Testing Fuel Economy Hacks

[@BigJohnLXV]

from what I've seen, in modern driving techniques, the most popular way to improve fuel efficiency is never stop for red lights

[@yeltsinhernandez7952]

lmao hahshah

[@masontorr6266]

Roll dem stop signs too, no cop no stop

[@wilfdarr]

This is one that drives me crazy: our mayor is always telling us how our cars are ruining the environment, but be dambed if he'll have the city engineers time the red lights!

[@kalmmonke5037]

they could limit speed limit enforcement to allow more momentum maintainence, less braking and powering up again, bc even with regenerative braking that is less effceint than maintaining momentum, and it decreases tire brake and battery electrics lifetime, which is less sustianble and adds to cost of living while wasting peoples lifetime on the road

[@wilfdarr]

@@kalmmonke5037 You could watch for the speed reduction and let aerodynamics do the breaking for you...

[@adamstahl8323]

Would definitely like to see Jeremiah make a big HHO generator

[@patrickmartin3322]

Yes, that would be awesome

[@Minecraft-md6fs]

So would i

[@ShaherIsmail]

1000000%

[@Psycho_912]

Curious to see what his system would look like

[@AndricKelton]

Yes

[@Bunnunoox]

Yes please! Make a hyper-miler!! Also you should power it with Jeramiah's engine. Side-note: Justin's really gotten comfortable and is a lot fun to watch as a presenter now!

[@charadunne]

Please

[@HenryMidfields]

Gotta say, everyone in general are great in hosting their videos. Whether it's Nolan (who got me into watching Donut), Jerry, or Justin, or anyone.

[@tokinGLX]

one of the best things you can do ties very well with the "watch how you drive, keep your foot out of it" line is to try to use your brakes as little as possible. obviously there will be times where you have to come to a stop, but there may be plenty of times where you can just let off the gas earlier and coast for longer, letting gravity and friction slow you down instead of braking.

[@marwerno]

Absolutely: My car has 178000km and still the first brake pads. May wife has a very similar car from same manufacturer and same weight. She had to change brake pads at 120000km EDIT: I just looked it up: they have even been changed at 90000km!

[@h5skb4ru41]

That is why I use engine braking, in some ways its much better than just abusing the brakes and having to pick up that speed.

[@dickJohnsonpeter]

​@@h5skb4ru41 Yep, especially engine braking down a hill. I can't stand it when people go fast and stop at the last second either, like why do that to your braking system? If you aren't racing you don't need your brakes as much as people think they do. I probably use my brakes twice as less as everyone else.

[@someguy9520]

I mean more brake pads and brake disc wear makes more tax dollars for the government 😂 I also almost exclusively use engine braking for slowing down. Only when necessary, the brake pedal is used Modern EFI engines also shut off fuel when engine braking. So when going downhill in the biggest gear, you burn no fuel

[@kadajawi6567]

@@someguy9520 Engine braking? Depends. Coasting saves fuel. Engine braking by changing down a gear or two or three does too, but your car won't actually generate any fuel. You simply save on brake pads by using the engine components as a brake pad.

[@OddBawZ]

Dude, Ecomod a small hybrid like a Honda CR-Z and then Ecomod something really uneconomical like a Hellcat to see which you can make a bigger difference on! That would be awesome.

[@benjaminwatson7868]

Odd, I know your secret now

[@dimitriskoulioumbis1082]

Ecomod an L3/33 lol

[@TaylorPhase]

im ecomodding a hyundai ioniq currently

[@kingjellybean9795]

Nah eco mod a hummer h3 that would be hysterical

[@bamastrac]

I drive 60 miles a day in a 01 grand marquis , definitely would like to see them do a ecomod on a big body car

[@NinjAsylum]

I can still remember the Mythbusters episode about the tailgate up/down. Literally one of the most definitive results in the shows entire history.

[@wise-dragon6776]

They did an episode with the semi also

[@LSFord]

@@wise-dragon6776 that episode was also surprisingly definitive. Like the semi made a huge difference and it got ridiculous the closer they got

[@WhiteWolfos]

What were the results?

[@drache444444]

@@WhiteWolfos iirc tailgate up was worse than tailgate missing, tailgate down was a bit worse than tailgate up, these nets that are supposed to replace the tailgate were best or second best, but covering it up completely was also very good.

[@thomasschwarting5108]

Yup, I saw that episode. With the tailgate open, the air DOES NOT flow the the way you think it should. I've been behind an open bed pickup and with a styrofoam cup back there and it just stays in the bed!!

[@impressivestory]

Justin is definitely a great addition to the team, and he's fitting in really well. Great stuff.

[@jetsamrover]

Came to say something similar. I've noticed a huge improvement, he's really coming into himself. Justin seemed awkward at first and was almost distracting, but he's clearly been working on his presence and probably receiving some coaching, and it is paying off.

[@ajman098]

Agreed. It was cool to see him host this!

[@jakuburban6289]

🙏

[@BusyB07]

geeez book a flight

[@pete-ph5xc]

It was super cool when Mythbusters did the hydrogen cell and it did nothing, but then turned around and showed that a regular carbeureted car will absolutely run off of direct hydrogen injection into the carb, at least until it backfired.

[@aaronfield7899]

What episode was that?

[@pete-ph5xc]

@@aaronfield7899 s4e10, exploding pants episode.

[@steam6626]

I mean, the hydrogen cell in the video here was powered by the engine, so there was no way for it to increase mpg

[@pete-ph5xc]

@@steam6626 fair point, though I thought the cell they were using had it's own power supply, but I could just be misremembering. In any case, the bigger issue was just that it couldn't generate enough volume any which way, even if it wasn't running off the engine.

[@josephoberlander]

Note that HHO kit actually "works" by tricking the O2 sensor into running the car lean. ($600 in snake oil and 10 cents in tinfoil) Yeah, repair bills might be in your future. Running modern cars super lean by tricking sensors won't end well.

[@OldManAzeban]

I think a hyper eco modded vehicle with Jeremiah’s hydrogen genny would be an interesting series. Start it in stages like Hi-Low and keep adding to it until you reach peak geek or startling efficiency!

[@censoredialogue]

replying to say i’d like to see this too

[@gurgleblaster2282]

Problem with hho generators and why they are a scam is they corrode. They will corrode before you get any cost savings.

[@lasskinn474]

just watch project farms video

[@chemieju6305]

@@gurgleblaster2282 they are also a scam because they use up electrical energy which one way or the other gets taken from the alternator. You take energy away from the engine, convert it from mechanical to electrical to chemical and then back to mechanical, losing a bunch of it along the way.

[@anydaynow01]

@@chemieju6305 Yep this, paying the conversion tax. It's not like they are using power that would otherwise be wasted like using exhaust heat or braking energy.

[@futureepix8801]

Justin did an awesome job hosting this episode. He seems so much more confident. Yet ANOTHER banger from the crew. Keep it up!

[@williamgallagher9891]

Justin is a forced addition that adds nothing to donut These bot comments, such as this one, are proof that they know this and are attempting to 'gas light' the audience into thinking there is actual support for this obvious shoehorn 🤡

[@MoonsOfEmpire]

Justin is fast becoming my favourite donut!

[@poppachoppa8956]

He sure is getting more confident, it’s actually cool to see the genuine shift from newbie to confident pro with the different hosts on the show as they join the team.

[@mgsPWlover]

It's so awesome seeing Justin get more confident in front of the camera, he's a great addition so far.

[@ViceFielder]

The savings with throttle and brake discipline is mind boggling.

[@josephoberlander]

Then again, it requires controlling your throttle in literal 1-2mm increments. Manual transmissions also win big here because the transmission isn't trying to out-think you.

[@dejangegic]

​@@josephoberlanderPedal shifters are amazing on automatics. Best of both worlds

[@josephoberlander]

@@dejangegic It depends if the manual mode is really manual. I remember years ago test driving a RX8 and it had a manual mode that unfortunately would out-think you such that if you pressed the brake to slow down, it would drop out of that mode below a certain speed. So at about 25mph when slowing down, it dropped to automatic suddenly. Zero engine compression all of a sudden. It felt almost like you shifted into neutral. And then had to re-start the manual mode. 1 2 3 2 (neutral, manual mode turns off).Stop. tap the thing into first from neutral to do it again. If you forgot, it went back to automatic. So only good for 0-60 runs I guess. GM - those are famous for letting you shift but once you get up to highway speed, it reverts to automatic. ugh. 1 2 3 4.. 9 (turns off trying to save fuel). You can defeat this with towing mode, but... really?

[@onur5737]

@@josephoberlander Automatics dont just shift whenever they like and try to out-think you. Simply put, they just shift when youre RPMs are too high for the load your giving or the power you need, so when its high RPM but youre acutally just driving constantly at 50kmh wiht no acceleration, it will shift up. Same with downshifting, if your RPM is too low for any kind of usefull load, then it will shift down to give you more "power". If you think that the Automatic transmission is trying to out-think you, then youre probably driving it wrong

[@josephoberlander]

@@onur5737 NO, modern automatics are all computer controlled and DO try to "help" you and "think ahead". Long gone are the days of old GM slushbox hydraulic-only automatics. I've had more than one rental shifting back and forth on a hill in slower traffic. 25mph, fairly steep mountain road, (driving over the mountains from the San Fernando Valley into the West Side) - typical morning commute. back and forth - give it a little gas and it would downshift - but the millisecond I let off ( since traffic is slow and I don't want to park in the person in front of me's trunk ) - into high gear it goes. Zero ability to hold a gear. While in my old slushbox (previous Buick I had before my current car), I'd just lock out 3rd by shifting to "2". This thing? Sorry, no gear selector - just a start button and a "D" button. Welcome to the new era of "automatics". Can't manually shift, can't lock out gears, and there IS no sport mode, even. It's basically as useless as a Prius.

[@MyTrevonne]

Using cruise control helped me the most. Leave early and just cruise the speed limit

[@a105-t5m]

old car or new car, a heavy foot will hurt fuel mileage

[@tbag6600]

almost like the old government saying when trying to introduce the new national speed limit wasnt a lie. "55 saves lives and Gas"

[@turbo_brian]

Actually the most efficient thing to do is to "cycle" where you moderately accelerate and then coast. So if you're on the freeway and want to go say 60 mph it's more efficient to slowly accelerate up to say 65 then coast down to 55 and repeat this over and over. Super annoying, but more efficient. This is because your engine has pumping losses associated with the throttle plate being closed so running it more open when you are using fuel improves the engine's bsfc and then coasting uses effectively no fuel. It's also super annoying to ride in a vehicle doing this.

[@drippingwax]

​@@turbo_brian I called that leapfrogging when I bought my first car in 2000, but I decided it wasn't worth the annoyance. Hypermilers call that pulse-and-glide. It is especially helpful if you do engine-off-coasting, but I don't know anyone who does that anymore.

[@drippingwax]

I have always timed lights. I never understand everyone else speeding to reds and then braking when it is obvious they cannot possibly make it. I almost always slow down for a light before the vehicle in front of me. It is always fun to roll up to the light and pass someone who cut me off.

[@mhrkrnm]

Justin really is a dope new addition to the donut team, love to see him get more comfortable infront of the camera!

[@xherta]

yeah i think this is his best video yet

[@Asymmetrical-Saggin]

@Don't Read My Profile Photo You really need attention that bad? Ok... I read your fucking name.

[@BramH...]

Agree 100%!

[@CodySmith-ks5it]

His voice kinda reminds me of hert from hoonigan

[@stott2hot]

@@xherta and he’s been p good the whole time, definitely a great addition

[@willythewyno]

I'd like to see Jeremiah do literally anything he wants.

[@discoball725]

he's so funny 😭

[@schwuzi]

i love jerbear

[@salvador4911]

YES

[@TheYardLimit]

That's my "Roadmaster" (Its actually a Caprice Wagon) featured at 11:11. The guy i bought it from built it to hypermile and tow trailers. It has a 5 speed out of a Chevy truck too. It easily gets 30mpg. It can get even better mileage if you keep your foot out of it.

[@tiagobelo4965]

huh, that's pretty neat, ever thought about giving it a common rail diesel? they tend to be pretty efficient and torquey, so a smaller one should be able to move that beast

[@101Volts]

I took part in the built thread for your 1994 Caprice Wagon, before Funkhoss sold it to you. He was getting north of 40 in it with his techniques. I suggested to him that he could add a WMI (Water-Methanol Injection) Kit and then advance the timing to get even better MPG, he decided to not add one. This was a few months before he decided to sell.

[@RUNFROMONYX]

the fact that they still have the "supercharger" on the vw shows dedication

[@drshocking1229]

honestly I feel like when they add the mods, they just do it for memes and keep it there just because it's like, it's funny to meme around-

[@zeroforcemember]

The ecomod would be a great series. Myth busters also did an episode where they used a bunch of clay to make a golf ball dimpled car

[@trashbandit2449]

Did it work

[@Love2Cruise]

@@trashbandit2449 Yes, it worked as a proof of concept. They used tons of clay to create the dimples, so the car weighs a lot more. In steady state cruising, the dimpled car returned better fuel economy. In real world, that improvement would be offset by the additional weight of the car. It wouldn't be feasible unless you want to create dimples directly on the body panels.

[@drippingwax]

As XKCD said, Mythbusters isn't science, they fail at basic rigor. They do fun experiments, but they often commit basic errors. As MadisonMPG said on the Ecomodder website in 2009, they claimed an "11% improvement on gas mileage with a dimpled car." They did 5 one-mile runs at 65 MPH and claimed they went from 26.x MPG to 29. They switched to a separate fuel tank, which they weighed before and after, so that was good, but only 5 miles? In the same thread, Darcane pointed out the amount of fuel that would be measured roughly would have been 11 grams of fuel. Also, a basic concept on Ecomodder is A-B-A testing, so they should have replaced the dimples to see if they still got 26.x MPG or if there was another effect. They made 1,082 dimples, which took several people hours. It is entirely possible that other factors changed. One of the administrators of Ecomodder, MetroMPG, who has done extensive modifications, and substantial testing, pointed out that they didn't use cruise control, Jamie tried to hold his foot steady. Could human error cause an 11% variance? Hopefully not, but there are many variables here. One thing that MetroMPG has done extensively is tuft testing. I want to see how the air flows differently and this is infinitely cheaper and accessible than a wind tunnel. How much do yarn and tape cost? He also checked their math. Adam said they used 503 g on the clay car and 478 g on the dimpled car, but that is only a difference of 5.2%, so they fail at basic math? Someone else pointed out that they relied on Jamie changing tanks when they passed the start point. That also allows human error. We didn't have test data like temperature, wind, full drivetrain and tire temperatures, etc. Ecomodder has a physics professor named Aerohead. He said that if Jamie is an engineer he should have remembered that the Reynolds number states that dimples don't work on an object larger than a golfball. Also, dimples work on golfballs because they spin. Aerodynamics are different on non-spinning objects. In "Car Aerodynamics - A2 Wind Tunnel - Wind Camp Tech Theory" on MotorTrend's website, Gary Eaker, who worked extensively with windtunnels, stated "Golf-ball dimples [...] do not work on cars, regardless of the scale of the dimples, unless your car is a 1.68-inch-diameter sphere spinning through the air with no ground plane." I will believe his experience over television entertainment--or take the dimpled car to a windtunnel.

[@drippingwax]

Justin said he overinflated his tires, but then said that other characteristics worsened, and then somehow called the idea a scam. Just test this. Drive 20 miles at 65 MPH on the highway without traffic at 32 PSI, 20 miles at the sidewall maximum, and then another at 32 PSI. Then actually test these other characteristics. Don't higher tire pressures improve braking?

[@trashbandit2449]

@@Love2Cruise hail damage

[@NAPBAM]

Justin did a great job this episode. Please have him hosting more!

[@dave_id]

Yup, killin it

[@kennedycurran2494]

no offense but I didn't really like it that much

[@dropitlikeitshot815]

Installing that hydrogen cell looked like fun also

[@danielorr6576]

I'm not even a car guy, but do love this channel, got my cousin a car guy watching you guys, I think we need to put Jeremiah brain to the test.

[@lawracks]

I’m glad Justin’s taking a bigger role in videos, I really like him as the new guy

[@mattm4476]

Yea he's a solid member.

[@bczarrockbeast6264]

I agree.

[@mattm4476]

@@jayamburn1959 sitting in my toilet trying to push out my Taco bell I had for lunch. You?

[@Slizzo82]

DEFINITELY do some sort of eco modding series! That'd be a great watch guys!

[@fantastic_mr.f0x]

Yes please.

[@yungboicontigo9278]

They should do that on a hybrid car like a Prius. Imagine if you add more MPGs on an already fuel efficient car

[@Dre_23]

Agree they should

[@rcintron123]

Please YES!!!!!

[@hotandnasty]

@@yungboicontigo9278 that or an Astro van

[@rcmike09]

For the obd2 fix, someone that actually knows how computers works, went through the "micro chip" and found ALL it did was blink the leds. Only 2 of the prongs actually had power going to them. One positive, one ground

[@rob_over_9000]

Yeah honestly you don't even need more than a rudimentary understanding of basic circuits to pop it open and see. The 12V and GND pins are always connected.

[@kingleopold6011]

The hero we deserve! Thanks !

[@anthonyfoster2784]

Placebo effect is real, if you believe its making a difference you will see results your hoping for.

[@archygrey9093]

@@anthonyfoster2784 Plus when people plug in these devices they start driving like grannies and then get amazed at how much better economy they are suddenly getting, so they actually are getting better economy but only because of their driving habit change

[@Bangin0utWest]

It would be easy to tell it doesn't worn eco modes just change the shift points so it shifts faster than sport which holds the gear longer if you didn't see a change in shift points it would show its a scam

[@LevelUpYourFandom]

damn i would absolutely LOVE to see yall truly try to make a hyper-miler car. ecomodding is wild but i would LOVE to see it work ahah how sick would it be to get a mustang to like 60mpg

[@hyundaitib2]

Tell them again I don't think they look at these comments hit the discord

[@richardidgaf8002]

I really loved this dynamic between them two lmao. Justin ripping up the windshield wipers as if it owed him money was hilarious.

[@colehartel7206]

Thwarting parking wardens!

[@Gervino]

love to see an eco mod, the cars always end up looking so goofy, i’d love to see how over the top you guys go with the concept

[@pauledwards9210]

Same!! Would love to see them eco modding

[@mattwilliamson1714]

Yes! Use a Gremlin… maybe turn the seats & drive train around and run it backward! 😂🤣🤣

[@craftyukraine]

That "style" looks like you want to pack your car to ship it somewhere into Uglycarland, for example.

[@NoHanLuke]

Not even lie. Sometimes I watch old donut videos to make me laugh or to cheer me up because when I was homeless and living couch to couch this is really the only thing besides making music that entertained me while going through those struggles. To this day it still brings me happiness to watch the new shit you guys are posting. Please keep at it !

[@herbosmoker848]

Seek Jesus.

[@snapnclap]

@@herbosmoker848 bro what? This dude is just posting a nice little nostalgia story

[@allhall0ws]

@@snapnclap think he meant it in a nice way

[@Snowfireblues]

The windows up thing is actually variable. If you're riding slow, the air resistance will be naturally lower, and thus the impact of the windows being open is much lesser. HOWEVER after a certain speed threshold, the air resistance becomes much higher (the faster you go the more the wind resistance affects you), so having the windows up becomes more fuel efficient

[@TheIVJackal]

They got a lot wrong in my opinion, the EcoModder community I'm sure would strongly object to some of the "scams" here, like tire pressure! Didn't even finish watching the whole thing...

[@BogeyTheBear]

Somewhere above 40 mph, the drag of open windows hits the mileage harder than buttoning up and using the AC.

[@Jaburu]

there really should be more info out there about the speeds where the switch occurs

[@N0ENEMIES]

When I was a kid I used to tailgate tractor trailers on long drives and the difference was astonishing. I could use about half the throttle I was using before I starting drafting off of the truck. You gotta be like dangerously close though. Terrible idea but hey, it was for science.

[@jonscot8393]

Same here at night, never used head lights from about 50 yrds out so not to freak out driver of truck but after about 30 minutes at 4 ft out my nerves were shot. as you say, for science. I'd put it up there with Russian Roulette?

[@SlyNine]

One time that truck goes over something your car can't. All that saved money is gone

[@motohrs2835]

I’m actually Truck driver and i hate when cars tailgate me so i always slow down on purpose to make them not to tailgate. it makes me think troopers following me cuz i can’t see the car

[@dhag72]

@SlyNine a moose or deer make one hell of an "instant speedbump" thats for sure. Especially when its "flung" in the air by the semi

[@rootz420]

Idk the way I look at it is you got a huge shield in front of you that cannot stop faster than a car can stop. The semi would plow through whatever obstacle and you could slow way down.

[@skiskicmb]

Good to see that Justin got in the groove and got his confidence up! Now he is matching the energy level of the entire crew. Good for you Justin!

[@ImDying2Live]

For sure, I didn't care for him the first video I saw him in, but He just seems like one of the regulars now and is great!

[@FNESSE]

Props to Justin for getting into hosting his own segments and videos now. Great addition to Donut 💪

[@oscargardiner3168]

good video he has something new every time

[@jeffersonott4357]

Yea, it’s odd, all the hosts are entertaining. How bout a women? (Not saying they are discriminating, I worked in garages for a decade, and never worked with a women, so I’m sure they are hard to find.). But, may be entertaining.

[@dougcook7507]

Using cruise controls is a huge way to help increase your MPG.

[@TheYardLimit]

Yes. But if you are really trying to save fuel. You turn it off up hill and let the car slow down a bit when going uphill instead of just maintaining your speed over a short rolling hill. Then get your speed back up on the back side of the hill.

[@gibbyg2001]

@@TheYardLimit That's probably right but it kind of defeats the point of cruise control.

[@brantkensinger3398]

This isn't true. Cruise control doesn't increase MPG. It decreases it. "Manual" throttle control is more efficient. In cruise control mode, the car has to constantly open the throttle (sometimes the whole way) to achieve a set speed. Manual throttle response allows the user to find that sweet spot where the car doesn't shift gears. Yes, you may decrease speed. But most cars are more efficient at 60 mph than at 75 mph anyway.

[@dougcook7507]

@@TheYardLimit The logic you start is the very reason not using cruise control is far less efficient. You foot is constantly pressing and releasing the throttle which results in accelerating more often. Which results in burning far more fuel. a simple Google search will result in verifying this.

[@TheYardLimit]

@@dougcook7507 Cruise control works great for hypermiling flat land. But if you are in an average car, especially with an automatic transmission, if you put the cruise on and come up to a hill, the car will sense the load but it wont know how long the grade is, its gonna kickdown a gear and give a bunch of gas to maintain speed. If you are really good at hypermiling, what you do is anticipate the grade. Perhaps use a downhill section to gain some extra speed without using too much power from the motor, and then back off the throttle coming up the grade. Let the car drop down to maybe 50mph from 65 or 60 if the grade is short enough for you to kind of coast up. Thats really hypermiling 101.

[@davisfamily9510]

Would love to see an Ecomod or Aeromod car build! Could even have two cars and teams to compete with each other and see who can make the craziest and most efficient car!

[@leafrika6520]

💯

[@HenryMidfields]

Yeah! +1!

[@tomasoliverasala]

yesss

[@bigchillin9359]

Greatest improvement would be best, bc I like the idea of ecomodding a challenger

[@Gizmos_and_stuff]

yessss

[@gunshotmike]

Finally, Justin does his own episode. So cool to see this. And he seems more comfortable in front of the camera.

[@pauldauria5689]

Really cool to see Justin come into his own and take the lead on this video!! Was skeptical about how much I liked him compared to the other guys, cause yall are all so awesome! But after this one I love seeing his personality and what he has to offer! Cheers guys, thanks for another great video!

[@foxxifi6521]

i would most definitely want to see an eco modded car, that sounds very interesting, especially if you can get gas mileage over 50 at least, that’d be super cool to see. I also would love to see jerry make a hydrogen powered generator for a car

[@MustachioFurioso9134]

Yes! I'd love to see the Donut crew take on an eco mod, and 100% should be a stupid inefficient car like a hellcat or something. Would be hilarious and fun to watch

[@poleosis]

Regarding "windows down", mythbusters also tested this one not once, but twice. While windows up will always be better, if you need cooling AC is NOT always more efficient. Below 50 mph, windows down is more efficient than running AC, and above 50mph, AC is more efficient.

[@Pain9682]

This is exactly what I thought when I saw this, lower speeds just doesn't produce enough wind reisistance for that to be efficient. I wonder how effective it is at different temperatures outside though..

[@TheAlbaniaGaming]

I always wondered this, and logically thought so, that when you went highway speeds is better to use AC (espcially considering the wind noise) and in lower town ones its better to open the windows, you can also hear better around you. Now i have it confirmed.

[@geemy9675]

@@Pain9682 exactly. it depends on a lot of factors. how fast you're going, how long is the trip, how much you're opening the windows, and how hot it is outside. also if you have big windows, glass roof, ac is working much harder to maintain temperature. if outside temp gets close or over your body temperature, so high 90's, the more air gets in, the hotter you get. driving long distance on the highway with broken ac and 100+ F REALLY sucks trust me. but if you consider comfort/gallon AC clearly wins unless outside temp is nice

[@matthewmiller3392]

Dependent on the A/C unit. Many modern A/C units have the option not to compress air while you are accelerating, only when coasting - they’re almost an energy recovery system. And certainly, keeping the windows up results in less loss of that nearly free cooled air.

[@Insanias]

the below/above 50mph may be true, however if its too warm outside and you arent getting much cooling from windows down, may aswell just keep them up and use the ac to get a temperature and turn it off. dont lose the cold air by opening the windows again because when you close them you'll have to use the ac to cool the car again

[@scooby45247]

i would like to see you guys take a guzzler like a hellcat and make it economically viable.. what shape does it turn into? whats the final mpg?? so fun, make it a series if you want..

[@patrickdougherty1981]

Definitely wanna see the eco mods on a crazy car! And can only imagine what Jeremiah could build would love to see both! ! You guys rock watch you every night keep the good content coming!!!

[@chrissinclair4442]

Ecomod, yes. Employee blowing them selves up with a hydrogen bomb, YES! Never heard off an HHO, but I would use distilled water. Wonder if it would cause more corrosion in the cylinders?

[@101Volts]

Well, you could also hop over to Ecomodder to see some of the things they've done. There's a pretty good thread about the "Aerocivic," a 1992 Civic that was heavily modded. There's also one about a 14 MPG Semi Truck that has a lot of aero mods.

[@peterkincaid6406]

@@chrissinclair4442 SORRY BUDDY. IT IMPLODES . IT IS A PURIFYING FIRE AND IS IN FACT IT IS THE PURIFYING 🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥 THAT PURIFIES ALL THAT IT COMES IN CONTACT WITH IN CLUDING URANIUM WASTE . MY FRIEND YULL BROWN HAD HIS RUNNING ON ABSOLUTE MOLECUL HYDROGEN 1,000 K TO THE GALLON. PURE WATER VAPOUR FROM RESIDUAL PURE FUEL ! I FIRST MET PROFESSOR YULE BROWN IN 1987. OBVIOUSLY YOUR BUDDIES ENGINE WAS NOT CONSUMING. NOT ABSORBING THE MOLECULAR HYDROGEN BECAUSE OF THE DIFFERENTIAL PRESSURE !! IE. HOW COULD I GET INTO YOUR HOUSE. .. IF I COULD NOT ENTER IN. AND IN FACT IF YOU KNEW WHAT HAS BECOME CALLED BROWNS GAS WORLD WIDE. YOUR PERSPECTIVE ON LIFE AND OUR FUTURE WOULD ALTER IMMENSELY. ! AND IN FACT THE WORD ALTER BECAME A LIFE TRANSFORMING EVENT IN YULLES LIFE BULGARIA AT AGE TWO !! P.S . THERE IS A MASSIVE CHASM BETWEEN THAT WHICH MAN SEES. OR DOES NOT. AND THAT WHICH HE KNOWS. .. AND DOES NOT !! GOD BLESS !

[@happybeagle13]

Please do more with Justin! You’re such a natural addition to the team. It’s like you’ve been there since the beginning. Keep it up boys!

[@Accion_y_Pasion]

I love that Justin is finally hosting he should get his own show he became an instant fan favorite

[@potatos_4_free]

And let's not even get started on his super cool name.

[@NeoAutodroid]

As a long time Prius driver, the biggest differences in MPG I've seen comes from 1. Good driving technique (rapid acceleration and deceleration kill fuel economy) 2. Make sure tires are properly inflated. Underinflated tires lower fuel economy substantially 3. Weather (not really something you can control) with hybrid vehicles the drive battery is adversely affected by extremes in temperature. On really hot or really cold days my MPG can drop as much as 8MPG. 4. Drafting actually works well on the highway but you don't have to drive as close to large vehicles as you think. Just keeping a safe 3 second distance from large trucks improves economy over following smaller vehicles.

[@Binski001]

Love to see a hydrogen fuel cell build with Jeremiah and an eco mod build with Nolan. A face-off to see who achieves the best fuel economy.

[@steampunknord]

I would love to see an eco themed high low. Even if it's not one where you make two eco cars you can still have fun in.

[@devonlambert9131]

Like a high low with two of the same car but modded for power vs economy? That would be really cool

[@steampunknord]

@@devonlambert9131 Well I was more thinking both modded for power while being economical but that would be awesome too. Cause we don't necessarily have to forgo power to be more eco..

[@Arellanog123]

I would too

[@Matt-vz5wy]

Just buy a Honda with a b series. Feels faster than it is, and stays fun to drive.

[@nuclear_legacy8689]

I've been a long time donut fan and just this week I got my license and my grandmas old Cadillac. Can't wait to apply everything I've learned from you guys. Thanks.

[@nickscarbrough9258]

Best of luck with the caddy! I know that's gonna be a fun ride

[@Makaya9s]

Please turn it into an American version of a bosozoku car. Everyone will either be scared of your car or impressed.

[@amsgamingandmusic]

Recently got my license as well- have bought an everyday car, now am buying a 1997 z28 camaro. I whole heartedly agree with you man :)

[@contraband1543]

Things gonna be wrecked in a month lol especially listening to these guys

[@nickscarbrough9258]

@@contraband1543 please take the negativity somewhere else man. Let the kid have their license and their fun

[@solarfinder]

I have to use higher octane, for detonation. Never thought I'd get better mileage, so I'm glad I educated myself. Good job guys

[@Simoxs7]

Don’t know about the US but here in Germany you get less ethanol in the higher octane fuels so they’re marginally better than E5 or E10 but cost way more so its more expensive in the end…

[@TheZXKUQYB]

They were wrong about top tier. Top tier gas is gas that has higher detergent it cost a couple extra pennies. Yes premium gas has, but it is all gas. It keeps your engine cleaner.

[@Arpan_akm]

Power petrol has a higher number of octanes than standard petrol. Power petrol reduces engine knocking, due to which the vehicle's speed and power increase. This is what we get for paying more for gas

[@nerdonabudget]

Expectations: "Testing fuel economy hacks" Reality: *no testing was actually done*

[@simonmarkis]

Exactly… disappointing video…

[@erlend1554]

This is donut media what did you expect?

[@nerdonabudget]

@@erlend1554 ​ I mean, in their recent "We Tested the Dumbest Informercial Tools" video they actually tested everything, and a lot of their other videos they're actually hands on and actually DOING stuff. This fuel economy hacks video was lazy, essentially just reading off answers that they found around the internet instead of actually testing it and showing the results from their findings

[@spamemael5129]

@@nerdonabudget because most of these are just logic, and they're experts on cars. Do you really need to test if removing windshield wipers works?

[@3p1ks]

@@simonmarkis Who cares. The test isn't what's important, the results are.

[@Dustinbuchanan76]

Yes to the Eco mod and yes to the HHO mod. I love seeing you guys build awesome things!

[@Megasteel32]

HHO does not work, no thank you. go to Project Farm and look at his thorough testing.

[@JSope505]

Eco mod!

[@manuelloureiro7076]

Eco Mod !!

[@kavenmendes]

Used to slipstream semis in my 71 VW Bus on road-trips. Helped immensely with engine load and fuel mileage

[@Trainboy1EJR]

Slipstreamed in a 98 Camry record 38.6mpg, I think my dad was only getting 26mpg. Slipstreamed in a 11 SX4 record 34mpg. The SX4 gets 18.8mpg at 70mph, facing the wind by itself. If I want to go over 62mph, slipstream is critical. Although if the wind is particularly sideways, nothing that can be done, and gas mileage is going to suck no matter what, and if it is super blowing in my direction, I have to keep the CVT in Manual 5 because it doesn’t have enough torque to overcome the wind in Manual 6.

[@Burlehmangus]

Depending on your car, your engine size/power, and alternator draw….the whole electrical stuff using more fuel can actually be big. Anyone who owns an older gem Honda Fit knows that if you have your lights and radio on, and try to roll up or down 2 windows at the same time, it feels like you lose about 30% power lol. Also, I think the manual transmission thing is because you can neutral and coast. I used to hypermile in my 02 Saturn sc2 by neutraling whenever I could and would get 80 mpg plus

[@HarpreetSingh-nw3ec]

As a guy who drives a 50 HP beater car, I understand and relate with your every word.

[@TheSuperBoyProject]

The manual vs automatic is a thing because the transmission fluid in the torque converter has parasitic energy loss due to it splashing around and converting the momentum of the fluid to heat. With the clutch that doesn't exist since all the rotational energy of the crankshaft is directed to the wheels. Automatics have only recently began to match or exceed manual efficiency due to locking the overdrive gear when cruising instead of relying on the torque converter and of course more gears.

[@jarilangerak9390]

Not the healthiest thing for your transmission however. Lubrication suffers.

[@DiustheZ]

Transmission thing has nothing to do with "neutral and coast" You're causing harm to your car by going into neutral at any high speed. You could get the same result by just "coasting" as your foot is not on the accelerator you aren't continuously injecting fuel into the engine at high RPM.

[@mariuscarausu9352]

Had a vw polo 2003,went on a 2 week holiday.Had to jump start the car,worked fine untill I turned on the light,when I turned on the lights I lost power steering.Everything was fine when I got a new battery.

[@NothingXemnas]

10:44 Adding to the talk: running the AC is more efficient if you plan on driving consistently above 40mph. In the city, window down doesn't affect fuel efficiency that much because the car is rarely fast enough for the aerodynamic drag to be so strong, so this tip is mostly for people who use highways for travel or work.

[@davidg4781]

Years ago, I had a 1 hour commute to work, mostly on the highway. When my ac went out, I drove with the windows down and saw a 2-3 mpg benefit, more in cooler weather. It might be dependent on the car, mine was a Ford Escort ZX2.

[@2A_Tree_Hugger]

Would it be safe to assume it also depends on how far your windows are down? Because of the amount of power my AC saps from my low HP motor, I usually crack the windows on the highway instead of running AC.

[@davidg4781]

@@2A_Tree_Hugger it might. My unofficial tests were between windows up, ac on max (I’m in South Texas) and windows down, ac off. Your mpg would probably be higher with windows mostly up, ac off.

[@McBenjiBoo]

@@davidg4781 Where you running your AC constantly when driving? One tip is to turn it on, get the car cool, then turn it off and use recirculation to keep the cool air in the car.

[@16driver16]

A 1.0L car will see a more drastic drop in mileage than a 6.0L+ because the engine will hardly notice the A/C compressor at that point. Also different size cabins to cool

[@TheDonutMan3000]

The best trick would be driving slower. At higher speeds most of the engine power is used to overcome air resistance, which rises exponentially. Double the speed means quadruple the air resistance

[@lilkris3008]

You just need to find what speed has the best return on mpg. For most sedans it’s around 65mph. I drive a Prius and find it’s about 68mph behind a truck I can get the same mpg at 75

[@TheDonutMan3000]

@@lilkris3008 seems about right for mine too

[@thetheatreorgan168]

Noticed this with airplanes, they’re flying slower now because an extra 50-150kmh makes the plane eat exponentially more fuel relative before peaking at Mach 1

[@101Volts]

​@@lilkris3008 --- I remember hearing of considerable aero drag starting at or around 45 MPH. Not to say you should go 40 MPH on every road around, though.

[@lilkris3008]

@@101Volts this is true but at 45mph you aren’t going far. At 65 you can travel 100s of miles while only loosing 5-10mpg where as doing 70 would loose the same from 65. It’s diminishing returns you have to go highway speeds but you don’t want to waste any more than necessary.

[@kassanova5430]

Shoutout my guy Justin. You can tell he’s getting more comfortable with the squad and the camera! Also I like how the Donut cast helps bring each other up. Big respect to that. These guys are already automotive content legends in the culture!!!

[@raven4k998]

all that trash is also increase the wear and tear on parts in your car as well

[@lolwhodis7817]

@@raven4k998 ok

[@oldjeeper9174]

Testing hacks without actual tests- this is a new level of science!)

[@LunaWaves]

other people did the tests they're quoting them. that's efficient

[@EconomicsMate1]

No matter what hack you use, at the end of the day, Clarkson said it best: "It's not WHAT you drive, it's HOW you drive"

[@roducliaharenvol8302]

If I remember correctly he was comparing a BMW and another eco car. I believe he was driving the BMW in low rpm or perhaps another method he used

[@jaskajokunen3716]

@@roducliaharenvol8302 Yeah if you drive high performance car "normally" You can be as economical as a prius

[@EconomicsMate1]

@@roducliaharenvol8302 correct. It was the BMW M3 vs the Prius. The Prius was going full blast and the BMW was just keeping up. And the BMW had better MPG

[@candle_eatist]

@@𱁬 jokes on you I don't have to

[@tomaskysela5523]

I'd say What is pretty important. At least in Europe the rule of thumb is if you wanna have fun drive. If you wanna save money, use public transport...

[@seshelbow336]

I like how you bust all these myths based on how you feel rather than actually testing them. Science 👍🏻

[@sirjolly81]

other people have done these test. You can snap your wipers and mirrors off if you like and post the results.

[@sicjoubert]

Agreed, the problem is the title "Testing Fuel Economy Hacks" but they only tested one. Using mythbusters for an example, I remember they tested AC vs windows but they did not show that even. Results were lower speed windows, higher AC. Expectations were them testing the myths not just talking about it

[@siamanspaps]

@@sirjolly81 then any other hypermiling project does exactly that…

[@r4nd7r04d5]

"Based on how you feel"??? Dude, you have to be braindead to believe those 'hacks' gave any result

[@thanosianthemadtitanic]

Use your head most of these just sound stupid

[@DamagedF0X]

Years ago in my 98 ranger, I used to draft semis all the time (45 min commute on a freeway). No question I got better milage. There's a weird space you have to get into though where the vertical turbulence makes the vehicle rock side to side that you will definitely feel.. Punch into that area about 3 or so feet and you'll get far better mpg, but still deal with the rocking.

[@lo1bo2]

In my 2017 Colorado I played around with drafting semis. Being in that first spot behind (NOT dangerously close) definitely improved instantaneous MPG. Boring view, though. My impression is that this technique works better on pickups and SUVs than cars.

[@alanchantiefighterskuanlia627]

I did that with a scooter with pillion. The top speed went up effortlessly. Then comes the wobble of death from the wind pounding left n right.

[@jamesprice2163]

Did the same thing with my 2.2 Sonoma and got estimated 5mpg better

[@WaspMedia3D]

Yeah I noticed that with my 2003 Pilot. You don't have to be 10ft away to get some benefit, I imagine especially with non-aerodynamic vehicles. But yeah, the back and forth pulling you have to get used to.

[@stpbasss3773]

@Captain Cornbeef Esq "slingshot engaged" 😂

[@jassemalzahrani4502]

I would absolutely love to see an ecomod im trying to do this to my truck and would lobe to see what you guys go through also!

[@drache444444]

theres a few mistakes here and there. overinflating your tires by around 10% doesnt create uneven wear and also doesnt ruin your handling, but will do a tiny bit of fuel saving. just dont overdo it. better gas -> here in germany we have 5% ethanol and 10% ethanol gas. the price is so close that calculation wise it doesnt make any difference, but my dad uses around 5% more fuel with it being only 2% cheaper. i dont recommend the 10% based on that. cold and hot gas at a gas station -> of course the tanks also heat up a bit. every gas station that i worked on could check the temp of the stored fuel at any given time, and in summer the fuel actually had a temp difference from night to day. 40°F during the night and up to 52°F during the day. but the pumps are actually programmed to take that into account while selling. here in germany they are calculated to measure what volume the fuel would have at 68°F and they account for it being colder and thus taking up less volume removing side mirrors -> mercedes measured during the 80's or 90's that removing both sidemirrors would actually decrease aerodynamic drag by around 15%, which is ginormous. thats also why most new semi-trucks here in europe actually have side cameras instead of mirrors. modern mirrors most likely cause a bit less drag than what merc measured back when they did, but still you shouldnt remove your mirrors for safety and legality reasons. also cars without mirrors look weird. auxilleries -> AC is a very big one, which can dependign on your model take up to 5% of your total cars power, especially in economy cars. but lights for example were measured by volvo -> they couldnt measure the difference between regular light on and off on their testing track. keep your lights on guys. if you have a biiiiig aftermarket stereo tho, keep it down, that will eat energy and with that fuel. and now the big one; transmission -> most cars and/or most drivers will drive more efficient with an automatic. you cant be as precise or as quick as an automatic gearbox, even if youre a racedriver. they banned automatics and cvt's from f1 for a reason. but, and thats a very small but -> if you have an econobox and you know the speeds you need, and the gears line up with your needed speeds, and you are very very good, quick and consistent with your manual gearbox you might safe a miniscule amount of fuel as manuals are mechanically more efficient in transmitting the power and are generally lighter. this all falls apart the moment you do anything outside of these gear ranges or even start to drive more sporty with a lot of gearchanges. but rolling on the highway with a fixed speed the manual can be more efficient. thats the case maybe 2% of the time. works for my dad with his driving style and commute, doesnt work for my mom with her driving style. sooo there is a tiny spec of truth even today. but if you go for efficiency in all situation a CVT is actually the best, as much as it hurts us car guys.

[@peterdarr383]

They also got the air circulation in the pick-up bed wrong - - beer cans migrate to the front.

[@partyman6666]

I agree with most of this. There are tons of flaws and left out considerations in most of the conclusions that they came to in thus video. A really big one is that you can't use a scangauge as an accurate way to determine changes in fuel economy that come from modifications. The best way is to fill up at a pump without topping off, drive, then fill up at the same pump until the pump auto shuts off when full and divide your miles driven by volume of fuel put in. Establish a baseline by doing this before the mods then again after your mods and with similar weather, traffic conditions, driving habits and routes and compare the results.

[@Wheagg]

We got e10 here and e15 now whether we like it or not haha

[@drache444444]

that sucks tbh i remember that my old moped didnt even like e5 and i had to pump the v-power or aral ultimate stuff for it or it would sputter and be down on power.

[@Wheagg]

@@drache444444 yeah but if you need it there are ways to get more "pure" gasoline from hardware stores and stuff. America is weird like that.

[@hopesndreamsperformance7617]

I'm enjoying seeing Justin hit his stride and getting more comfortable

[@Ess_Chalk]

I got a peek at the results from a safe-driving project that gathered a lot of data, which showed that people who drove smoothly had the best fuel economy. Smoothly meant no bursts of acceleration or sudden braking, which usually extended to a more relaxed overall driving style too. People who went out of their way to do things like accelerate before going up a hill so their speed evens out at its peak (not while towing though) usually ended up having worse fuel economy. I like to think that means good fuel economy through your driving style is as simple as not overthinking it and just driving sensibly.

[@Ic3g3org3]

acceleration doesnt matter that much, breaking does. When you break, all the energy used for move the car is wasted... So driving style that needs less breaking is more efficient.

[@importslunglowful]

@@Ic3g3org3 Actually, Genius. Acceleration pushes more gas faster for the use to create energy at a faster rate, OR ACCELERATION. So Yes it does matter, to the highest extent.

[@Ic3g3org3]

@@importslunglowful I didnt say it doesnt matter at all, but the highest waste of energy is wasted is from breaking. If you wanna drive saving fuel, start with the most important thing and thats predicting, so you dont have to break that much.

[@Damologist]

I love Justin, he has great presence and personality, and is a joy to watch! :)

[@dylan-nguyen]

One thing about the octane rating at 9:10 If you put 87 when you require 91, you’ll get worse mpgs and spend more on gas in the long run

[@chazeroni455]

YA. Came here for this comment. I believe It retards the ignition and/or runs richer to avoid knock.

[@1xBublex1]

smartass here - it won't only increase your mpgs but might potentially break your engine (if knocking gets too bad, although modern ecu comes with knocking safety modes where your engine is run rich to reduce knocking, which in even more modern cars needs a mechanic to remove (check engine light comes on), with moderately modern cars it tests for better fuel in a given period)

[@LinusAkaPano]

@@chazeroni455 This. The ECU will try it's best with what fuel you provide it. If you give it something outside its needed rating, then it'll try work outside that parameter, making it much less efficient.

[@LinusAkaPano]

In my BioPower SAAB i can run ANY %mix between gas and ethanol, and the computer will switch accordingly. (More % Ethanol, more HursPurs)

[@TheHenirik]

also because of computer controlled ignition and turbos (and to some degree injection), you can get a higher mpg on higher octane if the ecu is programmed right, but the consumption will most likely change less then the extra cost, and the change might only be on higher loads. its more likely you'll get a little bit of extra power, but again it depends on how the ecu is programmed.

[@gnaedigerfels]

Build the ultimate gas saver. Skinny light aero wheels with ultra efficient tires on it. get floorpans on the whole car, etc. Record the improvements after each modification to prove the theoretical knowledge you provided in this video

[@drippingwax]

Ideally you test each and every modification, remove them, and test again to ensure your data is from the modification, not external factors. That is called A-B-A testing.

[@drippingwax]

I believe that the original tires for the Gen1 Insight are the most efficient, but only at that tire size. Some guy put them on 4 spacesavers and put smooth wheelcovers on them.

[@filip000]

And that's how you get a VW XL1

[@Kottam_Yallawa]

4:54 low tire pressure increases rolling resistance and this loss is compounded by hysteresis loss, higher tyre pressure does add more miles per gallon ☮

[@kentaltobelli1840]

Yes definitely, sad that they dismissed this as a myth, it's well known that higher pressure improves gas mileage slightly and I run my tires about 5 psi over recommended. I suppose it was due to liability not following manufacturers recommendation.

[@Sugurain]

I drive a 80's Fiat which has really steep camber angle on the rear wheels from factory, I always thought they did that to improve stability in corners, but as it turns out, the main reason they did it is so that the rear wheels would mostly ride in the corners of the tires, thus decreasing the contact patch, thus decreasing rolling resistance, thus saving fuel. It's an cheap economic car, so it makes sense they'd do it to make the car as economic as possible. Not good for safety though! hahaha

[@3p1ks]

It saves more fuel for the cost of tire wear; it might not be worth it. The cost of new tires essentially cancels out the price of how much you saved compared to using factory standard PSI.

[@Kottam_Yallawa]

@@3p1ks maybe, I'm more of a 2wheeler guy (can't afford 4 wheeler 🥲). I've approached it theoretically, maybe in practice it will vary from vehicle to vehicle. ☮

[@seanthompson8071]

@@3p1ks Nope ... modest increases in tire pressure will not significantly change the shape of the tire and will not increase tire wear. The jump of 30psi to 45psi they did was foolish. Try a sensible 10-20% increase instead.

[@benpeterson7530]

On the automatic vs manual. Manuals usually weigh less (sometimes by a lot). That can make a difference.

[@Nordic_Mechanic]

and no pump losses

[@MetalLead]

@@Nordic_Mechanic Also when idle at a light or whatever the engine does not have to spin a heavy torque converter the whole time, and if you are downshifting to coast down a hill using engine compression that whole mechanism is more efficient. Autos usually use a lot more fuel if you don't bother downshifting in that scenario though for the same torque converter related reason. Most people don't downshift in autos and just coast and use their brakes down mountain passes and the like which means the engine has to use a small (similar to idle) amount of fuel to keep spinning the torque converter ready for you to press on the gas pedal. Doing this will make a difference on mpg going down a mountain, the same reason that you don't want to put your car in neutral going down a hill as some people think works. A good rule of thumb is that if you are speeding up at any sort of bike-like coasting rate while coasting down a hill you will be using a bit of gas in the engine, even in a manual. Manual drivers are simply more aware of this since they shift all the time and a manual car ecu will be truly putting 0 fuel into the engine in this downshifted, slowed by the transmission state. There have been many times (I live in a state with many mountain passes) where I have gotten 10-20 more mpg on a trip than I should have taking advantage of this at every opportunity in my manual car by simply sitting in 5th gear instead of 6th which maintained my speed down a hill. An auto with way more gears than a manual will obviously completely negate these negatives though like they said, just from general efficiencies during normal driving and depending on where you live and how flat it is, could make the hill stuff totally irrelevant. It's an almost negligible difference unless you don't downshift your auto anyways. If the road is not downhill or steep enough to keep speed constant or it is very steep (aka you are speeding up or not speeding up much while in the top gear), then there is actually a quite-complex optimization problem involved in determining whether coasting with a gear engaged and fuel cut or disengaging the engine and using some fuel to idle is more efficient, and a modern car with an automatic or automated-clutch gearbox will actually be evaluating conditions at all times to determine whether to activate a special "coast" or "sailing" mode where the gearbox is placed in neutral automatically and reengaged when power is requested again. This is the state I am talking about with an auto where it uses some gas going down a hill. It has to keep that torque converter running while it is doing all of this, and the computer has no idea what conditions it truly is in, unlike the driver. I guess what I am saying is that you should totally downshift your automatic cars and let the ECU know what it should be doing instead of cycling back and forth from idle back to engine compression. That's what the lever is for! Your wallet will thank you.

[@benjaminshaw852]

This is, easily, the most comfortable Justin has been in front of the camera yet! Love seeing him adapting to and enjoying the role! And yes please do the eco-mod and Jeremiah HHO videos!!!

[@macedindu829]

As far as efficiency of manuals vs. automatics, the gearing is one thing, sure, but as I understand it, the main thing was the torque converter. It essentially constantly "slips" a bit. Even assuming exact same gearing, the automatic loses energy because the manual is functionally locking the engine to the transmission once it's in gear and the clutch is engaged. Of course, the dual clutch transmission solves that issue.

[@JeremiahReddy]

Modern (2010+?) hydraulic automatics solve this problem as well by supporting torque converter lockup in most, if not all, gears. (Example: Mazda Skyactiv-Drive is said to support lockup in all gears)

[@fwebe2871]

DCT don't solve the net energy requirement, as automatic transmissions in general use more energy from the engine upfront to even work, which a manual doesn't. The slipping TC (which isn't even used in every AT, some use an electric motor instead) is one thing but the real problem is the base energy consumption, which makes them less efficient especially at lower speeds and which can usually only be compensated with using longer gears at higher speeds, as you can't use those longer gears at lower speeds. More gears can also decrease the gear steps, which reduce the overall rpm (and thus increasing engine load), when being light on the gas, but this usually won't compensate for the base consumption. Those transmissions usually use 8 gears where a manual uses 6 and have an additional 1-2 gears as overdrives. More gears increase the base energy consumption and the weight as well. There are other benefits to automated transmissions but efficiency isn't. For example the shifting strategy is consistend, which doesn't mean it is better at all times. To be clear, automatic transmissions have improved quite a lot, which reduce the difference between them and Manuals to a point, where the driver's profile makes the difference. On top they offer more options for hybrid power trains, which can in return save even more fuel. On the other side they cost more money, as they require more materials, software and maintenance. Nowadays it's mostly a decision between upfront car costs or overall consumption profile. For example a lot of german cars aren't cheap so initial cost isn't that relevant, but neither are they overly efficient which makes consumption more relevant for the manufacturers product line. In the EU manuals usually are used in cheaper cars or as an overall option to save money, as an increase of about 10% in price usually won't compensate in fuel efficiency against a manual, if it would do so in the first place. Automated transmissions really had their time when the NEDC was used for official consumption figures, as this cycle didn't allow an efficient use of a manual gearboxes, but any automated transmission could use the highest gears available. For example only at 50 km/h you where allowed to shift into 4th gear, even if 5th or 6th was the overall better option, while any automated transmission was allowed to use this same 5th or 6th gear.

[@petertroep9085]

@@fwebe2871 wow good read with a lot of information. Where can I read more about this? I would also like to add that the wltp cycle also sees manuals as more efficient with makes the price difference between manual and automatic transmission even bigger in countries with carbon taxes on cars (for example the Netherlands)

[@jime8532]

I'll assume the goal of increasing GPM is to save $. (duh). Question though, How much more does that 8spd electronic auto cost versus what a simple 3spd auto w/locking converter, just old vac and throttle signals to control shift would be?, and how long will it take for that small change in gpm to pay it back? If it needs service/repair I'm sure any gas saving $ is shot to hell.

[@petertroep9085]

@@jime8532 the change is probably more expensive than the economic value of such a car

[@shibusu4173]

13:27 I believe that older automatics also had less efficient systems to convey the power, since to allow idling while standing still older automatics use a torque converter with a fluid coupling to allow for slip. However, this is less efficient than having a clutch which can fully engage. Nowadays modern automatics can "lock" the torque converter at higher speeds, so it can achieve the same efficiency as a manual.

[@tylerblake3910]

All things equal, it seems clear that manuals still have the edge in efficiency due to the power required to run the automatic transmission's pump and the internal friction of the more complex gear set. Cars with automatic transmissions consistently show less power in dyno tests due to drivetrain losses. More drivetrain loss = less of the power your engine produces getting to the tires = less drivetrain efficiency. That said, all things are not equal when modern automatics have 8+ gears and shift so much faster and often more conservatively than humans.

[@SockyNoob]

Torque converter automatics require tons of gears in order to be efficient

[@joshjlmgproductions3313]

Locking torque converters have existed for decades. One of the biggest changes for automatics is having more gears (thus possibly taller ratios) than manuals.

[@chokeeweebee]

@@joshjlmgproductions3313 and one of the easiest ways to have more gears is to throw away the gears and use a belt and pulley to create an infinite amount of gear ratio's. Manuals would still win fuel economy tests if car makers didn't adopt boring CVT auto gearboxes.

[@drippingwax]

People insist that automatics are more efficient, but that is just to justify being lazy. They rarely have a source, just what they want to believe. The thing is, automatics aren't designed to be more efficient, they are designed to balance efficiency, longevity, smoothness, and probably other factors. There are absolutely factors that an automatic transmission cannot take into account, so they won't necessarily be as efficient.

[@InnaciKorushka]

I have tested the tire thing myself. It 100% increses mpg. "Overinflating" is indeed bad and will likely cost you more, but inflating to the max rated psi on the tire or just slightly below that increased my mpg by about 2mpg. For perspective, i was getting about 13/14mpg in my F150. Now im getting around 16mpg depending on how aggressive i drive. Havent changed anything else.

[@matthewgamman4303]

i would not consider that 2mpg being worth me risking a blowout, and tire wear increase though

[@nthgth]

Yeah, I'm still gonna go by the manufacturer sticker

[@josephoberlander]

Ah, those crummy low rolling resistance "eco" tires most new cars come with... Yes, I get 2mpg less in my Mustang running proper summer tires. But it also is roughly 50% better in rain, traction, and more importantly, stopping. It also rides much smoother.

[@nthgth]

@@josephoberlander better mpg in rain with summer tires? And better ride? Wouldn't expect that, but icing on the cake

[@josephoberlander]

@@nthgth No, worse MPG overall. But grip in the rain and ride/handling was easily 50% better. It went from light and (overly) "agile" to planted to the road.

[@davidtaylor6772]

Tailgating a semi works. When I was a terminal manager for a trucking company, I had to head from Atlanta to Florida for a trip. I coordinated with one of my drivers and tailgated his trailer while in a Prius and got 89 mpg on my first tank.

[@piedpiper1172]

A DIY or Don’t for making your own underbody aero plate would be really good. It’s a very common eco mod but also works as a performance mod. The rough underbody is often the biggest source of drag on cars and easiest to significantly reduce.

[@ElijahRoks]

Back in 2000 i made it from Southern Illinois to Phoenix (~1200 miles) on just under 3 tanks of gas. Over 400 miles per tank, in a 93 sentra auto. By drafting behind semis the whole way. Never got that good mileage again. Did it again across the valley(48 miles) in my '18 sentra and got 54mpg. Drafting works. But it's stupid dangerous.

[@dauf69]

Yupp. Even on a bicycle with a much smaller frontal area, drafting behind a car made pedaling much more effortless. Can't imagine how huge the effect must be for cars behind semis.

[@supergoat94]

I would have loved to see more of these actually tested even though going in we know it won't make a huge, or any, difference. Fun video overall though. But I would have loved if you tested a lot of little things and see what, realistically, the average person could do to save fuel. For example, a combination of windows up and accessories off and add in some of the other myths to see if the average person could actually drive like that and save 1-2mpg. Basically how unlivable would you have to make your car and driving experience to save gas without going full eco-mod.

[@LinusAkaPano]

That necessitates them paying for a full tank of fuel, and then paying multiple employees just to drive around and burn that tank of fuel. If 99% of of their sources claim it's unnecessary, it's better to take that at face value.

[@Ic3manWaddy]

Who doesn't want to see a Hellcat get 100 MPG

[@TytoMobile]

Problems with the HHO generator: -Energy used for electrolysis comes from the alternator, which loses some energy in the process. -Electrolysis is about 30-50% energy efficient for turning water into hydroxy gas -The HHO is being combusted by an ICE which is a 20-40% efficient process. -HHO tends to detonate, not combust at a sociometric mix, meaning engine knock

[@jungobango4815]

Stoichiometric*

[@mr.m2gilane]

And adding to all that, I don't think the car counts that as extra fuel without messing with ECU. It still will pump in same fuel amount specified in fuel map and whatever extra you can add through intake, it may or may not make a little more power but not save from fuel expences. Basically a dyi nos? Thats why LPG devices have their own controller to cut off main fuel and run on lpg. If you just squirt gas through intake without any modification to software, it just burns with same amount of fuel and...well, may send some pistons to low earth's orbit.

[@CreeplayEU]

@@mr.m2gilane That's why it's only worth it to get HHO equiped cars from some specialized tuning shops that do it. As I've seen here on youtube, they have their own controllers for the HHO and they even tune the ECU so you get better MPG and a bit more torque and power since it's hydrogen, and they get pretty good reviews from people that use it for like 5 years. There is also a guy from like Slovenia who modified his old Renault to run directly on hydrogen from water and there are even some more lazy ways like directly injecting water with gas into the engine and get higher MPG and it actually works, but that doesn't mean it's good.

[@patheddles4004]

If you install an HHO generator and you manage to get everything right, which is difficult, then you're basically just modifying your fuel: - Higher octane rating (probably not much higher) - Higher combustion temperature: increased engine wear, but likely some increase in fuel efficiency. Note that this design is only using the hydrogen, and discarding the oxygen - with the oxygen included it probably would cause knock, but the hydrogen on its own should reduce knock. I'd honestly be pretty impressed by anyone getting a net improvement in mileage using an HHO generator. Fun fact: I have seen HHO detonated at modest scale. Australian army was running a mock battle at an airshow, and they were detonating 2L plastic bottles full of HHO to make sound effects for the field gun. Very dramatic, and turned the bottles into hunks of melted plastic. I definitely would not recommend mucking around with significant quantities of that stuff. (also HHO is technically what powered the Saturn V rockets, but that's a whole other story)

[@scrumpydrinker]

A few more problems, The units shown on these videos are too small to produce HHO gas in any significant quantities. Feeding the amount of HHO that they do would have no effect whatsoever. When these units are shown working the water level in the tank barely falls(and the tank doesn’t seem to hold more than a couple of litres) If anything was happening one would expect the level in the tank to fall rapidly. Electrolysis yields are dependent on current levels, automotive electrical system do not have the output to run any meaningful electrolysis units. Most importantly, would you be really happy to have what amounts to a fuel air bomb running around in your car. There is a good reason why oxy propane and oxy acetylene torches have two separate feed lines as the gases are only mixed at the point of use for very pertinent safety reasons. With HHO the fuel (hydrogen) and the oxidiser (oxygen) are already mixed and it only needs a spark for it to go boom.

[@gabemccoy]

"Top Tier" doesn't mean high octane/premium. Top Tier is a third party certification for gasoline detergent types and amounts. I've seen no data to show if it improves gas mileage or not. You're right that an engine needs the octane that it was designed for, but Top Tier is separate from octane.

[@drippingwax]

Top tier is less likely to get clogged up, but how often is that a real problem?

[@abigails4088]

I noticed an improvement when switching to higher octane in my old NA Miata I used to have. but go figure a performance machine would benefit from something like that XD

[@jmoyet]

@@abigails4088 placebo effect. If you're engine doesn't require higher octane fuel it will just burn it like regular fuel and not make any better use of it.

[@iamstd2]

@@jmoyet depending on age and environment, an older car could have enough carbon buildup that it actually increases compression in the engine to require slightly higher octane. However... 1. This is extremely rare and the engine is usually toast before it happens 2. Any knock-controlled engine management will just lower the engine power if this happens.

[@miked9986]

Doesn’t improve MPG but can help with engine wear and carbon build up.

[@Saadlolwhy]

Justin has such a chill and laid back presenting style. Quite the infectious smile too.

[@joshuagomez3600]

Lol yah the point at the end I think is the most valid. There are a ton of things that can VERY slightly change your MPG. But the biggest one is your own foot.

[@blackdragonxtra]

12:08 A/C doesn't go through the alternator on most cars, which run their compressor directly off of the belt. Where as the alternator must always run to keep the engine going, powering off the A/C disengages a clutch on the compressor, almost completely removing the load on the engine, thus increasing efficiency. It can also be used to give yourself a little power boost when trying to accelerate with a weighed down car, while towing something, or just going up hill.

[@BoxFlyHaydn]

Absolutely. That's why in my track car the AC disengages at 100%. Because the manufacturer knew that when flooring it drivers want the total power. Just means that on a hot track day the driver melts!

[@bradnoyes7955]

@@BoxFlyHaydn Every Ford I've owned shuts off the AC at WOT.

[@pflaffik]

On a small expedition in the Cordilleras mountains of Philippines our old Lancer got severe brake fading going back down again, we had to rely mostly on engine braking but the small 1.5 litre Cyclone engine didnt brake much - fully loaded as we were. It was much too cold for aircon but turning on the aircon helped a lot on the he engine braking. It got painfully cold but the aircon got us down from the mountains in one piece (this Lancer was made for tropical climate and had no heater system at all).

[@Feintgames]

I would love to see you guys do an eco mod version of a truck, making it egg shaped but still a practical vehicle for hauling 4x8s and bags of fertilizer.

[@TaylorPhase]

a few people have modded their trucks actually

[@jonlawrence6338]

Australians have something called a ute. Remember Subaru’s Baja?

[@migueldorado7690]

this comment is weirdly specific

[@dylan8650]

@@migueldorado7690 someone had to say it. Thank you

[@drippingwax]

An aerocap, a tapered truck camper, helps with fuel economy, although you can't store as much under one as a normal camper.

[@80PercentAshamedOfU]

Drafting definitely works. It’s simple fluid physics. And myth busters easily confirmed it. The problem is rock chips and any road debris those semi tires kick up.

[@raven4k998]

does coke o cola burn?🤔

[@ReplayX2X]

Always love when Justin goes Hulk mode and rips things apart!

[@Marcus-uo5uh]

Fuck those windshield wipers 😂

[@vance836]

Drafting behind a semi definitely works. I had a 2013 GTI that I was able to get almost 500 miles to a tank on the interstate because I spent an hour driving behind a semi going 75 mph. Typically I could get around 425 - 440 miles to a tank (depending on conditions) but when I drove behind a semi; I was able to get from Tampa, FL to Atlanta, GA without my low fuel light ever turning on and pushed it to around 485 miles before I finally pulled into a gas station. If you are out driving; try to get behind someone with a taller vehicle (doesnt have to be a semi). The added gas mileage is like getting a free gallon of gas everytime you fill up.

[@NarwahlGaming]

As a truck driver I don't really mind being drafted. My only request though; TURN OFF YOUR DAMN BRIGHTS!! We might not be able to see the physical car but our mirrors are like the James Webb Telescope - a pin prick of light will illuminate the entire cab of our rig.

[@philipcsiki8033]

How tf can semis do 75mph, in Europe they can do maximum 90kph so about 55mph

[@Ej-en2lz]

My 2015 GTD (diesel GTI) has adaptive cruise control… drafting behind lorries is so easy and saves a lot on fuel… don’t even have to brake of accelerate ha

[@Ej-en2lz]

@@philipcsiki8033 in the UK I think some trucks also have auto braking if they go above 56mph when doing down hill

[@KurtisandHurdle]

@@philipcsiki8033 Europe is small and probably easier to drive through. Our highways need to take people hundreds of miles and trucks are very important for getting everything across our big country with over 3 million square miles.

[@sorinelpustiu5674]

I'd love to see you guys mod a gas guzzlers into a hyper miling machine

[@Black_Beard96]

For real, if they can do a 21 Tacoma with 33s and a lift, that would help😂😂

[@landonmatthew]

Brought my MPG average up from 30mpg to 35mpg just by driving with a lighter foot. Kept it consistent for over 1000 miles. I've got a manual civic and drive with a heavy foot normally so it was hard to adjust to 😂 but totally worth it.

[@orangejoe54]

I went from 25mpg to 32 in my RAV4 by not hitting the "sport" button every time I start it lol

[@landonmatthew]

@@orangejoe54 nice man that’s dope

[@drippingwax]

I have a manual 2000 Civic HX and had 50 MPG tanks from timing lights and driving the speed limit. Lean burn helps. :)

[@4450krank]

yup if there ever was a time for cruse control its now😄

[@amsgamingandmusic]

I'm in the process of buying a muscle car, and after I test drove it, I was very excited for the power in that thing. Of absolutely no connection at all, definitely, my everyday car's mpg went down noticeably 😅

[@TheStrawbunnyPrincess]

XD I used to love manuals for snow driving. in the 90's I felt like I had a ton more control in the snow when I could shift, but as tech got better... the advantage vanished

[@craigcampbell8560]

Manual transmissions still have an advantage when it comes to control, meaning you can hypermile better with them as well. That said, you have to actually try to hypermile for it to be an advantage. Most people driving manual transmission cars these days are more interested in the one HUGE advantage they will ALWAYS have over automatic transmissions which is they are a lot more fun to drive. Even econoboxes can be fun to drive with a manual trans.

[@igorokinamujika2073]

@@craigcampbell8560 Important to note that people outside of the US don't necessarily use manuals for fun. I certainly don't.

[@chriscrafting]

Manual vs Automatic transmissions: torque converter lockup- mechanically locked the torque converter above a certain speed (30-40mph) or in the top gear, reducing the hydraulic loses of the TC impeller/vanes and increasing efficiency with the engine directly driving the transmission.

[@Ancplaehh]

I think the "top tier" myth was referring to gas stations that are certified "top tier," not different octane gas. Like shell, gulf, Exxon (top tier) vs. BP, speedway, 7/11 (non top tier)

[@coalthedergsune]

don't forget costco!

[@peachy_panic]

Correct, top tier does not refer to octane, it refers to the detergents in the fuel. Top tier fuel is better at cleaning engines.

[@Pretzulkj]

There's also a kernel of truth to the "premium gas gets better fuel economy" myth, at least at some specific gas stations. Depending on where you fill up your tank the premium highest octane option may have less ethanol in the blend as compared to the regular/plus options. In many states almost all fuel is blended up to 10% ethanol, but some brands and/or stations will sell their highest octane fuel as a 0% ethanol blend while regular and plus are the standard 10% offering. 0% ethanol fuel blends give you noticeable increases in fuel economy, but generally not enough to make up for the difference between regular and premium prices at the pump.

[@RobertEmery]

@@Pretzulkj nothing to do with octane though.

[@Pretzulkj]

@@RobertEmery correct, which is why I specified it’s only at specific gas stations and it’s only happening because the premium blend has lower ethanol content. The octane is irrelevant other than that the ethanol blend at gas stations can be different for different octanes.

[@jasonconrad4314]

Really digging Justin as a more permanent part of the channel. Besides that, friends have been doing HHO for quite a few years, big enough system will show an improvement, but how much is really left to be seen. Jeremiah Def needs to build a bigger one and see what happens.

[@drunkenhobo5039]

Sorry but no - HHO generators in cars are complete nonsense. Doesn't matter how big they are, they run off the battery so will always be less efficient than not having one.

[@morsikpl]

"If you're driving a manual, you're doing it for fun" - me laughing out loud in Europe where very few people own automatic, and most would even not drive it because they don't know how, but they do know how to drive manual :D

[@igorokinamujika2073]

Same.

[@Eric2300jeep]

Loving the idea of you guys building an Eco car. Take it to one of the MPG drag races!

[@netronet1383]

Great episode, Justin. Speaking of fuel economy hacks, I've been watching ThunderHead289 get big improvements on mileage from putting a lawnmower carb on his Maverick's V-8. But it's not a simple hack he's doing. On the HHO thing, I remember a mechanic had a video on youtube showing people how to add hydrogen to the fuel mix by using an inexpensive passive system involving ingredients like baking soda and distilled water. It supposedly improved mileage, improved hrsprs and cleaned the engine according to his videos. Supposedly.

[@CRneu]

adding hydrogen to your intake mix will only hurt efficiency unless you redesign the engine(how it combusts the fuel, materials used, etc). Anyone claiming they added hydrogen and saw "immediate benefits" is lying or falling for sunk cost fallacy.

[@netronet1383]

@@CRneu I mean, I used the word "supposedly" a couple times for a reason. That said, I have read about legitimate research being done on purpose built hydrogen-enhanced combustion engines that are geared toward improved fuel economy.

[@Pheatan]

@@netronet1383 they’ve already made hydrogen powered cars that work well and are quite efficient. James May owned one. However it was rather expensive and if I remember correctly there was literally only one hydrogen fuel station in all of Britain at the time.

[@netronet1383]

@@Pheatan Yes, I am aware of the Toyota Mirai and the Honda Clarity as well. The research on hydrogen-enhanced combustion engines I referenced is different tech, though, and could be more affordable and a good transition to new, more expensive technologies.

[@Selendryle]

thunderHead's 40mpg in a v8 by way of a 'controlled vacuum leak' through a lawnmower carb.... i mean dang he could make a product out of his carb setup and tuner and save millions of people on gas :0 you definitely lost out on HP though

[@refreshing_ac6371]

great job hosting this Justin! loved seeing seeing more of him, he seems very in the zone. I’m surprised windows up always gives better mpg! i thought Muthbusters did an episode on that also and concluded that windows down at lower speeds (city driving) is better, and AC for higher speeds (highways) is better. maybe that’s outdated now, idk

[@p75369]

Yeah, I think MB concluded the cutoff was at about 50mph. Less than that and the windows are more efficient, more than that and the AC is more efficient. THough it'll certainly depend on your car.

[@Whxr3]

I love how descriptive the captions are as someone who has a hard time hearing the captions are truly a godsend

[@Goss5079]

Definitely down to see an EggCat Hypermile build and Jeremiah building an HHO generator. Make it happen for the people, Donut!

[@withintheglass2170]

This would be great if there was actual “Testing” involved

[@The_Real_Slim_Diesel]

As someone who works with gas for a living (fuels in the USAF)the temp actually does effect gas. If it’s closer to 60 degrees that’s the true and accurate weight Reading . We work mostly with above ground tanks but tanks under ground do need to have a daily conversation factor when we issue from a tank. Tho it is a very minor difference at small amounts in automobiles

[@drippingwax]

I was an Army fueler for 8 years. JP8 doesn't taste good!

[@drippingwax]

@@jayamburn1959 What is the expected response here?

[@robertt9342]

The gas pump thing also is corrected to a temperature, 15 degrees Celsius in Canada. Also I believe the myth busters segment shows you can be quite far back from a semi and still have a measure able gain to mpg.