Why Small Turbo Engines Are Not Efficient

[@teop7887]

My Alfa Giulia has the 2.0 turbo, and if I don't push it, the mileage is amazing. It really comes down to driver input.

[@juconkey420]

Had a Kia Optima turbo was getting around 31 in town. That's it you drive for economy and they deliver.

[@teop7887]

@ True, but there are plenty of FI vehicles, from Saabs to Volvos, petrol and diesel alike, that have achieved long odometer readings. By mileage however, I believe they meant consumption, not longevity. Cheers 👍

[@BluntEversmoke]

@@teop7887 Saab turbos break down constantly.

[@teop7887]

@@BluntEversmoke I know, but I didn't say all, I said many have managed to pull that long. Cheers 👍

[@nthgth]

And for some reason you don't think you'd see the same benefits from a modern V-6?

[@tokinGLX]

3:37 "as you floor it" well there is your problem right there. if you want fuel efficiency, why would you ever floor it, n/a or boosted?

[@joeyhayes3137]

Spool noises make me happy...

[@dmytrosednev9867]

Some people buy cars, especially performance models to floor them. These type of people never cared about the fuel economy. Bureaucrats told the car manufacturers to lower fuel economy across the fleet. They decided to cheat. They created these small turbo engines to trick the test and lied to us about their fuel economy. We ended up with inferior product in terms of fuel economy (for the way we drive), decreased reliability, and worse dynamic characteristics (in a way or lag). Environment loses out too. My 2l turbo from 2020 in a smaller car has about the same fuel consumption as my 2003 3.5l V6 in a larger car. Go figure.

[@stealthg35infiniti94]

@@dmytrosednev9867 Agree with you...Now some manufacturers want to put a 4 cylinder turbo in a full size pickup truck...It will very hard not to bury your foot pedal when loaded...I guarantee turbo replacement will be very common before 120K miles in these over taxed vehicles...The fuel savings money if any, will be negated by the expensive repair...

[@441meatloaf]

Why wouldn't you floor it? When manufacturers like Honda put small engines like 1.5L turbo you need to floor it to get the power and passing power you need on the highways.......

[@pharaongaming8617]

@@441meatloaf well that's the thing, if you want to get the best fuel economy you drive very very carefully and slowly

[@SpaceCadet4Jesus]

There's only ONE reason why my turbocharged 4 cylinder gets bad gas mileage.... REASON: It's because my foot's in it so far that the fan is clipping my toenails..

[@Dave5843-d9m]

An that's because its gutless ;)

[@ryansims9331]

You might want to trim your toenails.

[@ACERASPIRE1]

You're so cool Space cadet

[@campkira]

Don't had that problem with v6 or v8..... it is fine if you try to cruise on high way but yet again a Bugatti can cruise on the highway.... less power mean more rev and breaking and more rev.... while I just shipped down a few gear..

[@stevenjalopnik1342]

Yes you are correct. HOWEVER... let’s look at the 718 Boxster for example. The previous gen was a 6 cylinder and the new one is a turbo 4. They promise the same power from the new one with better economy. Perfect right? The problem is however that power is when the car is on boost however the fuel economy numbers are when the car has not hit boost. So you either have better economy or more power but not both. Therefore a turbo 4 is not a replacement for a na 6

[@233kosta]

People forget - your right foot is connected to a valve. That valve drains your wallet ;)

[@MFizzle777]

You mean that valve is then connected to your wallet!

[@MrFister84]

@@MFizzle777 Oh shut up.

[@leezhenxiang4146]

i smell the foot where it is burning the notes TT

[@keithgenegallo6675]

This aged like fine wine. 😭

[@sigmamale4147]

Agree, i can go through liters in ten minutes or 1 hour depending on how heavy it is lol

[@Kraigmire]

I always looked at turbo'd engines as having the smaller displacement when driven softly and a larger displacement when driven hard. Therefore, you will only get good fuel economy when you drive very easily, but you have the option of way more power when you want it. You just have to sacrifice that fuel economy when you want power. Kind of like cylinder deactivation, only more reliable.

[@siraff4461]

Apart from that smaller displacement being tied to lower compression or retarded ignition. Basically you have no power until it's on boost. It would make more sense to have the larger engine and turbo that to the same power level so it can run higher static compression and less boost.

[@goodmandiad2713]

I had (2) 2.0 Direct injection turbo engines, one in a Forester XT the other in a Sky redline. Both rated at about 250-260 HP. My 13' Accord with a 3.5L V6 (rated at 278 HP) and variable displacement was faster and got better fuel economy. The Accord ran on 3cyl when that is all you needed. Problem with a turbo is you are always into the turbo and asking more air and fuel to get moving and stay at highway speeds. If you paid attention to the whole video they reason for these turbo engines is not really fuel efficiency but to get the EPA numbers higher. That does not translate to real world fuel economy. Ask anyone with an eco boost Ford Pickup. The Accord with cylinder deactivation is 100% reliable. before 13' there were issues, especially on vehicles where people didn't step on it so much. Even in the older ones people easily got 200K if the changed the oil regularly.

[@TheNerd]

@Si Raff small turbo engines start boosting at like 1300/1400 revs... there is no safe "no boost" range cause if you drive it below boost you are going to damage your engine

[@siraff4461]

unheardNerd Go on then - what damage will it do if you drive off boost? This should be good.

[@TheNerd]

he did a very long video about this. driving in low revs. i dont remeber the name

[@MartinA-xh9ck]

A turbo engine is great power when you kick it and eco when you don´t. Its that simple

[@MMizie]

Which mean if I dont push the gas too much I can save more fuel?

[@unrealisticgoals]

@@MMizie if you dont push the gas at all you save all the fuel, amazin right?

[@rickeydriskill1096]

You have eco or boost. You cant have both.

[@Buzzzardtolife]

Carlos Soriano Q

[@stevepowsinger733]

Some say the flat torque curve means a turbo is less exhilarating to floor it. And a little boring to drive.

[@sruijc5250]

so.......what you’re telling me....is that they *ARE efficient* , but idiots keep flooring it while expecting to get 40mpg.

[@paulanderson79]

Exactly. No point buying a highly fuel efficient car and then driving it for performance. Unless we want to drive impossibly slowly then it makes more sense to buy a car that suits your needs and preferred driving style.

[@Boz1211111]

People dont have knowledge or patience.

[@spawnof200]

get a motorbike, you CAN floor them and still get 40mpg

[@Boz1211111]

@druss999 true. i am trying to drive as efficient as i can and most people find that laughable... when i calculate savings its a different story, though im not really sacraficing driving pleasure, efficient driving is my thing lol

[@thePavuk]

No, problem is that EU won't allow to make different motors so now you have 1 liter in cars where was 1.6-2.0 liter. Except some rare 2.0, biggest engines is 1.5 3cylinder.

[@jaredhoats1846]

I'm a proud owner of a 2018 Civic Si with the 1.5 L turbo that's pushing 20.6 psi from the factory. I get well over 30mpg under normal circumstances because I don't rev the crap out of it like some people do. They complain the mileage is bad; yeah it's gonna be bad when you're hammering the throttle all the time. These cars were built for the instances where you need power, but most of the time you want to save fuel. They're not supposed to be efficient when you're hammering on them

[@SoldMyHat]

I have an 18 si as well. I get better than advertised on the hwy. If I keep my foot out of it, very hard lol, I can get 40-42 mpg

[@yurrr7511]

I get over 41 with my 2012 Altima, and its rated at 32 hwy. my city mpg sucks tho lmaoo

[@rareginger2113]

18 Civic Hatch, hammer the throttle when taking off, slowly decelerate after getting about 5 over, barely hold speed with very light pressure on the gas pedal : 34-37 mpg city Same car, eco mode on, give as much throttle as I can while keeping a full green eco bar, 5 over to decelerate the maintain same as before : 42-43 mpg city 43-47 highway I only use Shell Premium

[@rareginger2113]

It's an EX Cvt 18 hatch (1.5L Turbo)

[@gwcrispi]

I'm going to buy one after the refresh. I'm going to hammer the throttle all the time. Who cares about mileage... Good thing I can afford all of the fuel I will be burning! ;) Great car.

[@LegacyIvyTerascale]

in short : you're Jeremy Clarkson , or James May

[@alessandromontalto823]

seems legit.

[@christianbro2]

Hammond doesnt count because hes crashed the car?

[@firdauszainudin7118]

hybrid of those two

[@GrockleTD]

@@christianbro2 he's very good at coming to a quick and sudden stop

[@wadimek116]

​@@GrockleTD Which is not very economical if you think about it

[@johnferguson7235]

Not everyone drives at sea level. Turbocharging makes a huge difference when driving at higher altitudes. For the vast majority of the time, the engine is operating at only a limited throttle opening. Sure, if you smash down on the gas pedal all the time, your fuel mileage will decrease. The advantage of the turbo is that the extra power is there when you need it; entering onto a freeway or climbing steep grades or over-taking slower vehicles. You must factor in the effect of the intercooler in any discussion on engine efficiency.

[@stevepowsinger733]

The air forces realized in WW II that superchargers ( turbos cousin) increased high altitude hp.

[@LunarStrike]

@@user-zv8qg1co4z I never had a time where my lancer es n/a 120hp engine had me wishing to have more hp to get on a freeway ramp lmao. And on my 18 wrx if I go above 10% foot pedal then rip fuel economy

[@theJ4ZZ]

All the Coloradans raise their hands 😝

[@SkylineFinesse]

@@LunarStrike mine could do burnouts in 2nd-3rd. Beast of a car for what it was

[@Explorerman1293]

All I heard was V8s are more efficient and I should drive my turbo car fast for better mileage. Don't correct me, this is the world I want to live in.

[@kunalsing8164]

Danny Daskalakis That’s my world as well

[@daszieher]

I like your world, which is why I have the best of both ends described by you: turbo-six :D

[@jamesavery6671]

Larger engines just make the power easier. Don't need all the turbos, cooling lines etc just to make 400 horse with a v8

[@Playboysmurf1]

Is your world Venezuela ?

[@MrCarguy2]

Playboysmurf in Venezuela there are no cars to start with

[@tyquanwashington.8510]

I swapped the tiny K03 turbo out for a larger gtx2867r on my 2.0 ecoboost. The K03 spooled almost instantly but power died around 5k rpm. The 2867 hits peak boost at 3.2k and makes power all the way to redline (6.5k). It's also making 150 more crank HP. Wasn't expecting to also increase mpg. I now get 32 mpg doing 80 mph.

[@FlatPlaneCranky]

This makes perfect sense. My 2017 GT Mustang gets 26 mpg on road trips. My Kia Optima gets 28 mpg on the same trip. You can guess which vehicle I prefer when I go!🏎

[@EvanMoon]

The answer is more stickers

[@guerrillaradio9953]

lmfao.....

[@mr.357mag4]

Evan Moon And the flame paint job

[@TheRealChilly]

"This sticker added 5hp"

[@boonvang708]

I started putting racing stickers on my computer i havent noticed a difference at all.

[@1barnet1]

The answer is water ethanol injection. Just look up the german BF109 late variants.

[@notmirelnam248]

You mean to say that when my engine is making more power, it's also using more fuel? Say it ain't so!

[@remissiveslave]

It's not so

[@topkek7003]

not necessarily, compression ratios play a pretty big part. two engines can be using the same air fuel ratio at the same displacement, and provided the fuel can handle it, the engine with higher compression will make more power while using the same amount of fuel.

[@christianbro2]

Its efficiency what we are talking about. If you accelerate little with a smaller turbocharged engine it is going to consume less than a naturally aspirated engine. If you accelerate more, it is going to consume more. Consumption tests are done when accelerating little, while in the real world, you may accelerate more, so consumption is higher than its rating, or higher than the former N/A engine.

[@marcuscook5145]

Not always, but if the extra power comes from forcing more air at once, then yes... because more air always requires more fuel to keep the same A/F ratio. You can make more power and gain efficiency by adding compression or reducing friction. You can also improve breathing, which while not cramming more air per stroke, does shift the powerband into higher revs... since you have to rev higher to make the power afforded by the airflow, you have more strokes.... so you still use more air (and fuel) overall if you want to take advantage of the power gains.

[@mkkm945]

I owned a Suzuki with a Fiat sourced 1248 cc 4-cyl diesel. Really small engine. 75 horsepower and 143 ft lb torque. I used to joke that my fuel economy numbers were directly related to my mood. During my 3 yrs of ownership, I recorded anywhere between 30 mpg and 62 mpg which almost entirely depended on how I was feeling and how calm I was driving. That engine was stunningly efficient at, say, 2000 rpm cruising in 5th gear. Push a little to overtake someone and it would be the exact opposite. I think that means that a good/sensitive driver will be able to get good gas mileage if he/she is paying attention but the average joe may struggle to replicate EPA.

[@panther105]

When my Firefly Turbo kicks in around 3000 rpm, it feels like an extra cylinder just started firing. My 3 cylinder, 1 litre suddenly becomes a fire breathing 1300. Hold onto your hats....!!!

[@EngineeringExplained]

Stay safe out there!

[@panther105]

It's too slow and fun to drive it recklessly. No airbags in 1991..... Easy to work on....but a death trap any way you look at it. Just incredibly cheap to drive to work.

[@Dockhead]

i see these engines being used in the new fiestas etc in the UK and really wanting to know are they really as effective and powerful as a 4 cyl engine with near enough same HP or even less, there is a fiesta ST model not sure on exact name of model, but its sports a 140hp 3 cyl turbo engine and im just amazed that old 6's didnt make that much more before.

[@anthonywebber2211]

panther105 i had a non turbo Geo Metro, and every two weeks was a massive $35 fill up lol, i now have a 2005 Chevrolet Colorado and $40 is only half a tank now

[@conman1395]

pescod96 look at Carwow's comparison between the 3 cylinder and 4 cylinder Fiesta ST

[@rnreajr9184]

I have a small (1.4 liter) turbocharged engine in my car. I have never gotten the mileage that I thought I should be getting, and this video helps a bit to understand why this is. The real blow that I got was when my car was in the body shop for a month (let's just say that it was the busy season, and that's all I have to say about that). I had a rental car that was a larger sedan with a V6, and it got better mileage than my smaller car. I still miss that rental car...

[@estuardo2985]

yeah, you have to drive like "that annoying slow person" to get those rates.

[@beenusirimanne]

So short version: you get a small Turbocharged car to drive it sensibly for economy, and to have some power reserved for when you need it. I own a 2006 Land Rover Discovery 3 with a 2.7 litre diesel V6. On the Motorway doing 70 it happily gets above 37 Mpg, whereas in the city, it drops to around 27. The key is just how much you put your foot down; that thing pulls away hard once the turbo spools up, but then the Mpg goes out the window. Its all down to driver input and how you drive it. A good example of this is the race that Top Gear did with a BMW M3 and a Toyota Prius.

[@Ozaneee]

Diesel engine are more efficient than a gasoline engine

[@mattdagger1480]

I’m surprised you didn’t mention the option of higher octane fuels to help reduce knock. Typically the factory turbo cars use a specific type of programming or ecu tuning called “adaptive octane logic” so the computer can tell how high of octane the fuel it’s using is. Most of the factory turbo cars tend to “recommend 91/93 octane” for this reason. Basically it allows you to use 87 if you want but once the adaptive octane logic sees the fuel is crap it can set a lower cap on the engine timing. So let’s say you use 87 octane. The adaptive octane logic may set the limit of the timing to 12 degrees(advanced) well once you throw 93 in the tank and the sensors sample that fuel it will increase the limit of the timing from 12 degrees to lets say 20 degrees (advanced) resulting in more power out of the same calibration all while keeping the engine safe.

[@mikep490]

True and a lot depends on how heavy your foot is applied. With a light foot the tranny can shift before the turbo kicks in. This eleminates knocking and the need for high octane fuel. In this scenario, lower octane fuels can get the same MPG w/o spending that extra 10% per gallon. Regular gas ignites easier and burns quicker than premium which can improve MPG in some scenarios. For the lead foot driver, premium offers more power and better MPG but offset by the fuel's expense.

[@thresh-]

That's because higher octane gasoline doesn't actually affect fuel economy. That sales point is a scam. If that were true, all car manufacturers would design engines for that type of gas, and all gas stations would serve only that type of high octane gas.

[@mattdagger1480]

@@thresh-idk if I’d use that as a blanket statement for all cases. Especially since if your engine is knocking and the fuel system has to retard the timing to compensate for it. Then in that situation the higher octane would result in better fuel economy. It’s not as cut and dry as most people think who haven’t studied the modern fuel systems in the past 10-15 years honestly. No disrespect intended. People just assume cause they knew long ago it’s the same as it was. And fuel systems and the methods engineers use to control the fuel systems have drastically changed over the past few years.

[@mattdagger1480]

@@thresh- for someone like me a master tech of over 15 years to hear someone say higher octane dosnt affect fuel economy it just shows people like me you don’t understand Timing, long and short term fuel trims, what octane actually does and how it affects an engine, or how modern fuel system works. Again no disrespect. But when people say blanket statements like that it really shows the uneducated ignorance unfortunately

[@skaownz234]

@@thresh-Domestic car companies are lobbying for a unified 95 octane fuel. Makes sense since we have so much corn ethanol. Lower octane fuel has a little more enthalpy, but not being able to compress it as much is costly.

[@benjaminturpin2749]

I used to have a modified jetta tdi diesel. That thing was awesome. No matter how hard a drive it. I never really got under 35-40mpg in town. On the highway 50-55 all day long.

[@Remenschneider]

Knock is not the only reason for having to use a rich mixture, exhaust gas temperature is also really important. Water cooled integrated exhaust manifolds really help increasing the lambda = 1 operating range. Current Miller Cycle engines like the EA888 Gen 3b can even run stochiometric in their whole operating range. Also, this video really should have had a bsfc diagram in it to show why smaller engines (higher internal pressure) are more efficient at partial load.

[@rupunzel6299]

Not quite so simple as richer fuel mixture and retarding ignition timing to prevent pre-ignition (aka Detonation). Combustion chamber shape and piston top shape, detonation sensing, intake air temperatures and LOTs more factor into how good any turbocharged engine could be. To overly simplify turbo engines are less fuel efficient due to the need to enrich intake mixture does not factor in or account for how some manufactures have addressed these innate problems with turbo engines. Example: Saab-Scania's B234 & B204 turbo engines have a static compression rating of 9.2 to 1 and they achieve good fuel economy with balanced shafts (which consume power increasing fuel consumption). This is done by using a well designed pent roof cylinder head combustion chamber and a domed down piston top and intake/exhaust gas flow pattern control. These basic designed in factors work to prevent detonation with and without turbo boost. The more complete burn due to the afore mentioned design elements in the engine work to help the intake charge burn more complete which extracts more energy per intake charge, lowering emissions and resisting the potential for pre-ignition aka Detonation. To monitor pre-ignition at each cylinder burn cycle, Saab uses in cylinder ionic sensing of the burn in process via the spark plugs. Before and after the intake charge is ignited by the spark plug, the spark plug becomes a sensor to detect pre-ignition and alters when the spark plug is fired as needed, per intake cycle, per cylinder. To address intake charge temperature rise due to air compression by the turbo an intercooler is used to reduce the heat of the intake air. Intake air to the intake manifold is monitored for air temperature and air density. Both are figured and LOTs more factors are figured into the amount of fuel to be injected per cylinder. These factors work in conjunction with the ionic pre-ignition system using the spark plugs. The Saab-Scania turbo engine management system IS one of the most sophisticated out into production with with many technical features that are not recognized, appreciated or understood. Beyond Saab-Scania's turbo engine management system, the B234 & B204 engines are built really tough, durable and very strong to withstand the increase in torque of a turbo engine. It is also why a stock B234/B204 can be up boosted to 450 lb/ft of torque as delivered. Forged chrome-moly steel cranks with nitrided bearing surfaces, Forged chrome-moly steel con-rods, forged aluminum alloy pistons specifically designed for turbo engine duty made by Mahle with oil jets and additional oil cooling features. Stout main bearing and bottom end design, good coolant flow design to move the larger amount of heat produce by a turbo charged engine, oil cooler with thermostat to reduce the oil's operating temperature.... These are just a few technical reasons why Saab-Scania was able to produce a reliable-very durable turbo engine with good fuel efficiency for a given power requirement. These same turbo engines also features low emissions. Turbocharged engines are essentially a two stage pump system that recovers some of the heat energy that would have been lost via the exhaust to increase overall engine efficiency. The added plus of a turbocharge, lower exhaust noise due to conversion of that pulsed energy into rotational forces to drive the turbine.

[@AlanTheBeast100]

I've had a Honda Accord 1.5L (turbo) for about 2 months. The mileage is phenomenal for this size car (which also delivers up to 192 hp / 192 ft-Lbs over a ridiculously flat "curve" if needed). Using the OBD port and monitoring the wastegate position and manifold pressure, it's easy to see when the turbo is active. And that is when needed to get performance. Thus the small displacement engine consumes as little fuel as needed when cruising and more when power is really needed. That said, at higher cruising speeds the wastegate does close, but only enough to get the power needed. In effect, that exhaust energy is being recycled to help the engine breathe enough for the power demand. So, the small engine will use as much air and fuel as a larger displacement engine _when needed_. Lighter engine= less mass = less fuel to accelerate. And the consumption numbers v. my previous Accord prove beyond a doubt that a small turbo engine is a happy and efficient engine. And, BTW, no knock with 87 octane as recommended by Honda.

[@jonniemactyler7929]

I've got a 2017 Honda Civic Hatchback. For life of that car so far, I have averaged 41-42mpg according to the in car mileage tracking computer. So probably a little less than that, but I would put it at about 40mpg based on when I actually did the math of mileage/gallons at fill-up. I drive 40 miles per day and mostly on the highway going to work & back. Even when I've been driving around town (stop & go) and sitting in fast food drive through lines a lot, my mileage hasn't shown below 36mpg. I don't remember filling up where the computer showed less than 40mpg. Basically if you aren't getting 35+mpg in the current model turbocharged Civics, then it is your driving to blame. Most perceived gas mileage problems in vehicles are the fault of the driver.

[@monkeymind3067]

It is Japanese HONDA

[@Encryptus1]

I have a Geo that does 52mpg... 😂

[@shapshooter7769]

In the case of extremely high boost pressures, I remember seeing twin-fuel systems being implemented. Check out the Ronin Exige, which uses a separate methanol system that is injected into the engine after reaching a certain boost threshold. The methanol increases the octane rating of the gas being burned, at the expense and complexity of two fuel systems in a single car.

[@davidperry4013]

I usually prefer Naturally aspirated engines but, twin turbo 3.0 V6s are quite nice.

[@a124as]

Turbo lag is a killer though

[@jonkess2768]

I changed from a 1,4 litre four cylinder 90 PS to an 1 litre threezylindet engine with a turbocharger and 95 PS and i am down from 6,5 litre per 100 km to 5,5 litre per 100 km. For me thats a huge Deal because i save around 250 Euros a year.

[@satsumagt5284]

The biggest advantage of the smaller turbocharged engine is the low end torque, so that your new turbocharged car (might even be a Volkswagen) has more low end torque and can sustain lower revs at high speeds

[@Encryptus1]

I have an 993cm3 n/a from 1999 that does 4.6...

[@MikhailFrolenko]

Pedro Pereira but how much hp does it have that’s the question

[@Encryptus1]

@@MikhailFrolenko 56 bhp.

[@KarlAlfredRoemer]

My Polo 6N1 build 1996 1 Liter 4 cylinder Big Block needs 5 Liter\100 Km.

[@Wpjgdmtu]

For a little while I drove a '13 VW CC with a manual and a stage 1 93 tune to about 250whp. I was getting 28-30mpg combined and I could squeeze 36mpg on the highway. I think the real advantage to these turbo engines is you get all the fun while on boost and then when you're cruising on the highway off boost, it turns into a fuel sipper.

[@Intrepid175a]

I worked for a Lincoln/Mercury dealer back in the very early 80's. In my three years there, we sold one Mercury Capri with the 2.3L turbo four. It was a nice little car but the owner brought it back to us several times complaining about lousy fuel economy. We checked it out each time and it returned proper gas mileage when we were driving it so there was nothing we could do. We talked to her several times and could never figure out what her problem was when she finally said it. "My salesman said I could have V8 performance AND 4-cylinder gas mileage!" Ok, "now" this makes sense. The service manager resisted the temptation to tell her that her salesman lied through his teeth to her and simply said he was mistaken. She could have V8 performance OR 4-cylinder gas mileage but not both at the same time. She didn't like that answer and we were never able to satisfy her on this issue.

[@nissan2829]

Idk about all of that, but in my experience, keeping at a lower speed seems to do pretty well. I have a 2013 Ford escape with the 1.6 EcoBoost engine. Epa estimates it at 33 hwy mpg. I can achieve it if I keep it at 65-70. However in Texas most of our speed limits are 75 or hwy. If I run 75, it gets about 28. Well under the advertised amount.

[@kingsford6540]

This has to do with gear ratios, mostly. The beginning of your last gear is around 60mph, so under 70 you're still in the low revs

[@joecool4656]

@@kingsford6540 air resistance is also considerably higher

[@gototcm]

Keep in mind that the highway fuel efficiency ratings are due to the way cars are tested using a dynamometer and the the Highway schedule which is run at 60 mph, not 75 mph. Higher speeds means more drag (proportional to the square of the speed) resulting in lower mpg.

[@tempk490]

Interesting video. I have a 2017 Jetta with the 1.4 turbo. EPA Highway estimates are 40MPG; doing 65 mph I'll get 48+. I've been delighted with the gas mileage so far, however I'm not doing autocross or anything.

[@ManuJohn380]

Brandon M but Toyotas new 2.5L NA with 200hp is getting 45mpg at 75-80 mph in a much bigger car.

[@Iraqveteran-ke6qu]

Same here. It's been great to me.

[@jakegarrett8109]

What's funny is my 30 year old Mercedes gets better than "Highway EPA" while doing burnouts... I laugh at those ratings, so innacurate, I've never made that bad of fuel economy as they say.The diesel Merc makes 35-40 mpg driving wild, rated 27 from EPA My Mazda on the other hand is impossible to hit its rating (best was 19.2 MPG drafting a Semi for 150 mile run at 65mph in 6th, the EPA rating is not realistic). Normal in town is single digit, but who cares, its a rotary, drive it like you stole it!

[@Tonyx.yt.]

epa rating could be not so realistic but still much more realistic than current (soon replaced) european test... the worst one was a extremly small 850cc 2 cylinder car, official numbers said 56 mpg, real world town+countryside+highway is only 35 mpg...

[@flybyairplane3528]

Tony x the EPA tests, are done on a dyno, Indoors, no road bumps, no wind, and the fuel they use NOBODY can buy.

[@fracturedrealitygaming1326]

I’ve got a 2012 Chevy Cruze with the 1.4L I4 Turbo, and I’m completely turning this thing into a project car. I’ve got a wrecked ‘15 Cruze LTZ with the rear axle disc setup that I’m stealing for my Cruze, and I found a ‘13 eco that caught fire and was totaled out I’m gonna be cannabalizing the frame and splice welding pieces into mine to elongate the engine bay so it can accommodate a 2JZ engine with a twin turbo setup. And it’s thanks to watching your channel, among others, that I’ve been able to realize i can make this happen! Yours just taught me the how it all works at it’s base so that i can understand how my vision can come to life. So thank you man

[@TL1000S97]

Two things: 1) This is not only linked to "small" displacement engines with turbo. It is the same for any *gas* powered engine using a turbo. 2) This is only relevant for gas powered engine. Diesel-turbos is another discussion.

[@electrictroy2010]

It applies to turbo diesel too. More air is more diesel burned (and my 51 mpg Jetta TDI drops into the 30s) .

[@petarmiletic997]

​@@electrictroy2010 More air is more diesel burned, but more work is done so efficiency of the engine is the same or even better. Of course fuel consumption is NOT the same thing as efficiency. Exampe: drive at 70km/h, engine load and efficiency is lower, but the car itself is more efficient since there is less power wasted to overcome air resistance. Double the speed to 140km/h, the power required to overcome wind resistance increases 8 times!! (since air drag power increases with the cube of the speed). Far more energy is needed to travel the same distance so the car is less efficient BUT the engine is more heavily loaded and runs more efficiently. Fuel consumption increases even if the engine is more efficient. IE fuel consumption doubles, but the work done quadruples, so the efficiency increses. Another simple experiment, try pulling up a hill in 5th gear and then try the same hill at same speed, so the power required is the same, but in 3rd gear. In 3rd gear load is lower, there is less boost but it will burn more fuel to do the same work as the efficiency is lower. There is no efficiency penalty for high boost on diesels because diesels don't require full load enrichment. In a gasser full load enrichment helps prevent knock but also causes decreased fuel efficiency, so a gasser might even burn less fuel when you downshift for less boost uphill, which is practically never the case in a diesel

[@kennedy796]

Then explain how semi trucks can still average 6-8 mpg towing dry vans when 10 is the most they ever will do?

[@yourbabyboyfriendonlyme2485]

@Chris Russell Shhhh elect........ might learn something. Granted it is 4 grade stuff. I just wish they had . well telling would be telling. sorry

[@dieselgeezer18]

@@kennedy796 these engine are like huge 14L V8 engines. How do you expect a good milage from such a huge engine?

[@humanperson900]

"You dont want that many cylinders" *laughs in Italian*

[@jammi__]

Yeah, the Italians drive mostly in small Fiats with tiny powerless engines and always did. I think you meant *laughs in top 1%-er*

[@arunkumar-ok4pm]

@@jammi__ I think he was referring to the Lamborghini

[@Giuliana-w1f]

*laughs in bugatti*

[@beezanteeum]

@@Giuliana-w1f Bugatti is French, not Italian

[@Giuliana-w1f]

@@beezanteeum i know, i'm just saying that bugatti has a lot of cylinders Just ignore my old comment

[@TheKingkingg]

Good day. We went on a road trip in our 2016 EX-T Civic with family of 4 and fully loaded trunk for a Trip from Timmins northern Ontario to Sault Ste Marie Ontario (557km) around Lake Superior with lots of hills. We got 690km on 1 tank before fueling up. So it cost $80 Canadian in fuel... that is amazing.

[@TCPUDPATM]

Please confirm this on the topic of cooling with AFR: Adding fuel beyond the stoichiometric ratio 14.7:1 does not add any more heat because there is no more oxygen to burn the fuel with. It extracts heat from the engine when changes phase from liquid to gas (as described in the video), and exits the engine unburnt with thermal energy that leaves the engine cooler. Diesel engines also use this technique, the side effect of this can clearly be seen as soot exiting the exhaust as black smoke. So rolling coal = blowing raw fuel out the exhaust. Not very efficient.

[@complexdevice]

Diesel engines don't use this technique. They are compression ignition and direct injection (in modern diesels) and therefore do not need to overfuel to avoid knock. Sometimes they will smoke a bit before the boost kicks in and cleans up.

[@TCPUDPATM]

I meant that they use over-fueling technique to keep EGT down, among other things. Not knock. Thanks for catching that. Can't have pre-detonation when there's nothing to detonate!

[@Trundle_fkr]

TCPUDPATM PORTS diesel's run lean. Over fueled the exhaust temperatures increase because of after burning during the scavenge cycle.

[@Bartonovich52]

Overfuelling cools the air and makes it more dense. This is why water injection is used in the same way even though it adds nothing for combustion-even on (especially on) turbine engines where there are also no knock considerations.

[@Trundle_fkr]

Turbines have extremely high exhaust temperatures and often use fresh air to cool perforated turbine blades. Excess fuel in a diesel is burned during the scavenging cycle causing high exhaust temps and burned valves.

[@Kaz-ct3vd]

I was very impressed with ford focus and its 1L 3cyl turbo, easily got 45mpg. It has a very low torque range so you could run it below 2k rpm and it still pulled nicely. I didnt get it for performance though, wasnt as peppy as a normal 2L.

[@Knel89]

Stay out of boost and your gas mileage will be good 🤷🏻‍♂️ (really hard to do sometimes)

[@mitch9521]

hard to do when it makes 9ft.lbs of torque without boost.

[@AlanTheBeast100]

Hook up an OBD to it (if you don't have a gauge) and monitor. Even in cruise there will be some boost - and that's okay - just means you're getting energy out of the exhaust flow to make the small displacement engine behave bigger. Lighter engine=fuel savings.

[@kurtsaenz4048]

Kris91790 Very true. Really difficult when the turbos start spoiling at 1,700 rpm though, but it saves gas.

[@yourbabyboyfriendonlyme2485]

@@AlanTheBeast100 Well I know OBD2 stats suck. The O2 sensor just sucks at its job(to freaking slow). Plus on some vehicles they have the o2 sensor behind the cat ALSO. SO WHAT IS THE SECOND CAT TELLING THE FIRST O2 SENSOR TO DO? DON'T SAY IT JUST TELLS THE ECU THAT THE CAT IS WORKING! When Pee my brain tells me that i'm peeing (1st o2 sensor) , If when i'm peeing my pee is black (2nd o2 sensor) brain says WTF!!! WHAT DO I DO! It freaking does something.

[@AlanTheBeast100]

@@yourbabyboyfriendonlyme2485 I'm not saying it's a substitute for a proper boost gauge, but it does indicate the MP albeit with a slight lag. (I have Bluedriver with an iPhone and it's quite good in this regard - other readers may be better or worse). The important thing here of course is not the OBD-II - it's that turbo on a small engine means more energy extracted for the fuel burned. That's the main point.

[@BigHeadClan]

Many v6/v8 drivers have been saying this for years, in a more performance oriented application a smaller turbo 4 engine often performs worse than larger engines in the real world. Happy to finally see a video from EE covering this topic. Most recent examples of down-sizing fail is the Porsche 718 Cayman/boxer, went from a 6-cylinder to a turbo 4 and make identical MPG to the old engine. Had them simply lowered displacement but kept it to 6-cylinders the same result would have been achieved without loosing it's wonderful sounds.

[@counti41]

BigHeadClan its not about power its about a useable torque curve. Turbo cars can have a more useable torque curve. If the torque comes on sooner less trottle/work needs to be applied to get the vehicle moving. And turbo cars normally have a 4000rpm range where the torque will remain higher than a NA vehicle which you only get peak torque at a single point in the rpm range.

[@BigHeadClan]

Gareth Wynter more torque means your car is in boost to generate that extra twisting force. Which means more air and fuel required the more torque that is generated and also no turbos also have only a single peak torque number the curve is just flatter across a larger range. Need to remember hp is an expression of how much work is being done.

[@BigHeadClan]

@wrxassa if you think Porsche shared almost anything with VW mechanically youd be mistaken. Some parts or a motor with Audi yes but that is a more premium segment. Also what does VW or Porsche have to do here?

[@counti41]

@@BigHeadClan hp is how fast the work is being done.

[@BigHeadClan]

@@counti41 yes and horse power is a Metric calculated based on torque you can use either Metric when discussing durability thanks for coming out.

[@DS-TRUCKS]

Also keep in mind how people drive turbocharged vehicles. When you're driving a big V8 you have to drive slow to get any decent kind of mileage. Where most people who drive turbo cars always have their foot down... Who remembers the old days when you could literally watch the gas needle move in a V8 truck?

[@otm646]

DonnaSean this is exactly the problem. These smaller turbocharged engines are usually dramatically more powerful than the naturally aspirated motors the owner was previously driving. Thus the driver accelerates significantly faster than their old car ( horsepower requires fuel either way) and then complains about the economy.

[@timfox2344]

‘71 Olds Toronado ... 455cid, kick in the 4 barrel over 70mph and just watch the gauge drop 1/10 every few seconds

[@lildeena1]

I just rented a Kia Soul that did that from full tank to a half a tank Driving 80 on a short 80 mile trip. Watched the needle move.

[@johnoehrlein8379]

70 Chevelle 396 ss w/cowl, yup it def was a race, those were the days

[@youkofoxy]

see the gas needle move? that remember my first car, i kind fixed it... but the ECU was think the engine needed more gas. in fact the poor thing barely moved.

[@Godlyhank]

Using a suzuki baleno 1.0 RS (112hp one) here in UK. I can confirm torque and power crossover is very volatile if you are heavy footed...however. if you know your pedal and maintain some patience you can find that very small sweet spot that allows very very high efficiency on the road in it. Basically where the turbo wastegate is cranked open the tinyest amount to allow the increase in torque without the near 2x hp jump.

[@dj_paultuk7052]

Just to say, Saabs never suffered from knock. Or at least they prevented Knock. They Developed APC in 1986. (Automatic Performance Control). They used the spark plugs as a sensor and detected the onset of knock from the ionisation within the combustion chamber. If knock was about to occur, then timing would be adjusted. And/Or, boost levels reduced. This meant it effectively detected the Octane of the fuel. Better quality of fuel = more power. A Saab 9000 Aero has standard compression ratio. And yet with 98 Octane RON fuel, it can run 1.4 BAR (24 PSI) boost pressure with no knock. Giving a max of 310bhp from its 2.3L 4cyl. Ford are only just getting to that now with the Focus ST and RS.

[@Bartonovich52]

No SAAB 9000was getting 310 hp stock... and modified it wouldn’t have lasted as long as newer cars.

[@eaglefat9398]

Most OBD1 and Every OBD2 car i've ever worked on had a knock sensor which is basically just a microphone on the engine block, you can pop the hood while the engine is running and give the engine a light tap with a wrench and you will hear the idle drop because the ECU will pull timing, All ECU's do is advance timing until it senses knock then retards timing back down until it stops thus getting the best ignition timing possible. Nothing special or new.

[@buggs9950]

"No SAAB 9000was getting 310 hp *stock*..." Did he say stock? No he didn't.

[@flybyairplane3528]

Paul Taylor too bad GM killed the SAAB.

[@dj_paultuk7052]

Yes @ 310bhp the B234R is at Stage3. My point is, a stock engine will run at 1.4 Bar boost with no Knock when using higher quality fuel. FYI: The above is a just a remap. A B234R can be taken to 500bhp on a completely stock engine. They are fully forged from the factory so dont need to be touched. ALL Stock hardware goes to 310bhp. Then you just change the turbo and injectors and head for 500.

[@JohnnyAmerique]

Got a 2017 GTI. If I drive it conservatively, it gets fantastic fuel economy, around 30/36. However, if you even begin to open it up, that drops dramatically - even routinely getting into boost range a bit cuts the fuel economy in half or more. Overall though, it’s a fantastic engine: The power is there when you want it, and for the 90% of the time you don’t, it’s as economical as a Civic.

[@xXlURMOMlXx]

Tyler Brown damn I get like 25-27 max driving normally 😅

[@johnferguson7235]

Exactly, if you drive like a mature adult, the turbo doesn't cause any dramatic decrease in fuel economy.

[@sykokilla77]

Word love my 1.8 Passat. 40 hwy 33city

[@xXlURMOMlXx]

John Ferguson I’m under 2k rpm 85% of the time! I don’t even use more than half pedal often bc I’ll be far over the speed limit at that point, even stock!

[@marco1173]

"25-27 max driving normally" You're not driving it "normally", trust me. Those engines are so eager to rev it's easy to overdo it. I love my 1.8T but I know I could be getting better MPG if only I could bring myself to ease off on the gas pedal a little bit. It's pretty much impossible for me, though lol

[@BabyBugBug]

They are extremely efficient. My Jetta gets 42-48 mpg on the highway depending on how fast I drive. In the city it is around 30 mpg. The car goes from 0-60 in about 8.5 seconds. I couldn’t be happier with it. The only problem with the TSI engine is that I will have to get a carbon cleaning in about 60k miles to keep it in top shape.

[@hackfreehvac]

It is more efficient to go with a turbo 4 over a V6 but the problem is the power, especially the very low RPM power of the Ford EcoBoost, is addicting and people have a hard time not putting their foot down from a dead stop. LOL

[@ericverster4069]

lol the 2.3s are wicked fun. 5.0 not too shabby either.

[@Hollywood49]

@@ericverster4069 I miss my 1.6 Fiesta ST. Always had power whenever you needed it, regardless of what gear you were in. Too bad the seats killed my back, otherwise I'd still have it.

[@vikeskie]

lmao my moms Escape with the eco boost is fun as hell to drive. it’s quick at the low end

[@billydavison3134]

I'd personally take the duratech family of engines over any of the ecoboosts in terms of reliability.

[@thetechlibrarian]

I would take a good v6 over a turbo 4 any day

[@amp888]

It's an interesting discussion, but it's missing real-world data. The lower displacement turbo engines are less efficient in specific conditions, but you haven't presented any data about how often those conditions are actually encountered, in average driving situations for average drivers. For example, do most people spend most time driving in stop-go traffic (inner cities or congested roads) and constant speed (highway), with low throttle percentage?

[@Lazerecho]

amp888 look at this guy critical thinking! Just like the "mpg" is based off a specific test, and if you aren't driving that test at the same altitude/temperature why should you get the same results?

[@slanahesh]

I think his point is more towards the performance oriented driver, who may be considering a lower volume engine as a way of having their cake and eating it too. In normal day to day driving you don't usually floor the throttle very often.

[@amp888]

Sure, but that doesn't support the video's title. Perhaps "When Small Turbo Engines Are Not Efficient" would have been more appropriate.

[@neptronix]

That's a good point, my dude

[@peterm3861]

I think so, too. The video is not wrong but as always you can't speak generally. I'm sure Jason knows exactly what is going on and he also didn't say that the shown scenario is the case in every situation. But yeah, your video title would be a bit better for sure. I think he could have mentioned the words "downsizing" and "right sizing" since that is the topic here.

[@g1981c]

good video. what i like about Toyota hybrid system is that no matter how hard i drive it fuel economy stays good. it's really incredible - the combination of naturally aspirated engine and regenerative braking makes for a system that pretty much doesn't care what your right foot is doing - it always returns the same good fuel economy. of course some people may dislike the feeling and sound of an e-CVT but to have responsiveness of a V6 with over 40 mpg in real world driving - i'll take it.

[@Mgoblagulkablong]

Finally someone talks about this! Here in europe all we got the last decade were tiny 1.0l - 1.5l (mostly 1.0) turbo engines, because the official fuel economy numbers were measured by a method called NEFZ, which was pure protectionism of the europeans thanks to lobbying. In that test only 5 hp were used on average. So turbo engines did not use their turbo at all in the fuel economy testing and the official fuel economy mostly depended on how small the engine was, the smaller the better. In real driving these cars depend completely on the turbocharger to make power and use at least 30% and up to 50 % more fuel than the official numbers say and their emissions became much more toxic than 20 years ago (and they were allowed to emit 10 times more and a much more dangerous kind of particles than diesels, extremely harmful to the human body). You americans don't know how lucky you are that you have EPA, best fuel economy testing on the world.

[@slanahesh]

exactly, those tiny 1L engines suck so bad.

[@philipph3421]

Mgoblagulkablong sorry, but I want to see your sources. I highly doubt that the stated numbers in your comment are true. It is true that the recharging of the battery, applying duct tape to the gaps, changing camber and toe, having higher pressure in the tire, lowering weight by removing additional stuff, and tuning the ECU to maximise efficiency is allowed within the NEFZ, but with an additional error of 4% the difference of the date isn't that high. The cycle is a standardised on with 66% of city driving and 33% of highway. It includes the coldstart and even fuel and temperature and air pressure are standardised. The resistance (rolling and air) is mesured and applied to the dyno on the forehand. The thing is that every vehicle runs through that cycle to be able to compared. But in the real wold the variables do change more. And especially the position of your right foot, if you know what I mean. The thing is that speed and throttle position do matter more in the real world through air resistance at high speeds and the lamda value and thus the enrichment of the mixture. And it is obvious that if it's floored that it's neither efficient nor clean, because what you are doing is solely asking for acceleration. If you want to achieve the bumbers stated you need to shift early, slightly touch the accelerator pedal and use the same things the manufacturers do. But it is possible to achieve good numbers close to the ones mesured in the real wolrd. F.E. the Honda Jazz is stated with 5.3 l/100km. I achieved 5.5 myself. And this while the battery was charging and haven't used duct tape. Nobody said that it is easy to achieve the numbers, but nor impossible. In the USA the cycle is not that efficiency focused. This results in numbers closer to the ones achieved by most of the users. Both cycles are there for a reason and NEFZ gives the manufacturer the ability to let the engine mork in it's most efficient way. This is not the most realistic but it shows what the engine can do. But when asking for power the car has to deliver. It's the same thing with BMW and the "Deutsche Umwelthilfe" who tried to sue them for manipulation of the diesel because when the car was floored or reached high rpm (so there was asked for power) the EGR valve closed. That's becaue they we're asking for power and therefore fuel needs to be burned with fresh air. It's obvious that EGR needs to be closed in this scenario. And it's obvious that if you use the accelerator pedal and ask for some power that fuel needs to be burned. The emissions do mostly are clead out by the cat. But they depend on how you get the fuel in the car. Having a look on the emission classes I belive that most new cars are much cleaner than before.

[@Tonyx.yt.]

agree... european test is totaly fake, 0-50 km/h in 27 seconds... WTF that's why smaller is the engine, higher is the difference between official and real world consumption... my car has a small 4 cylinder naturaly aspirated engine and despite claiming worst consumption than tiny 3 cylinder turbo, in real world has better consumption, yes it lacks of torque but who cares, just drop a gear.

[@nokobz2624]

@@philipph3421 'herzig' nice jew name. Don't believe him, this jew was born with a snake's tongue like all of them are and never stops spitting outr lies and confsion to the gentile slaves....

[@paultasker7788]

I had 1.4tsi and it did 45mpg average. The worst I ever got was 40mpg and best 52. Gave it back at end of finance deal. Only Kept our other car a 1.6 naturally aspirated does 35mpg in same conditions. The turbo is a lot faster yet more economical. Not as economical as promised but still very decent for a mid sized petrol car. Before that had 1.2tsi and that did 43 with 38 worst and 60 best. So that could do more in right conditions but on average did less. Makes me wonder if 1.4 is about the sweet spot. I test drove a 1.0 turbo and most of the time was only in mid 30s economy.

[@DomitionX]

I used to drive a 2012 Buick Regal GS with a 2.0l Turbo LHU engine (manual). It would regularly get 23 mpg as I drove to work. I bought a 2018 Mazda 6 with the 2.5l turbo a month and a half ago, and now I typically get 35-37mpg on the exact same route. I know the 2.5l is tuned very differently and it's a lighter car, but still even for those numbers.. Mazda's real world tuning is legit for my use-case.

[@ryanclark457]

DomitionX it depends a lot on the manufacturers because they all default different heat sources by using extra fuel, some of the newer engines use water injectors for cooler temperatures during combustion which requires less wasted fuel to keep the temps down. Also several newer transmission setups involving many more gears allows for cruising at higher speeds at very low rpms which produces much better fuel economy. 9 gears vs 4-5gears lmao what a big difference it makes

[@JonathanHart-n4t]

The shape and mass of the vehicle determines fuel mileage given an appropriate engine size range

[@chir0pter]

Great video! It'd be interesting also to see how say an LS motor stacks up against a DOHC V8. It's interesting to compare how the E92 M3s compare to the Corvettes of the same era in terms of mileage, for example.

[@MaliciousSRT]

A 2.0L @ 14.7psi boost is now a 4.0L. Its really just displacement on demand, going down the highway its a 2.0L again, but when you pass its back to a 4.0L.

[@justinjones5281]

SP392 not exactly but first comment worth giving a thumbs up

[@MaliciousSRT]

close enough ;)

[@siraff4461]

The big difference being flow rates, intake air temps and active vs static compression but you're not all that far off.

[@kurtperdew2391]

There is no replacement for displacement.

[@goodmandiad2713]

I had (2) 2.0 Direct injection turbo engines, one in a Forester XT the other in a Sky redline. Both rated at about 250-260 HP. My 13' Accord with a 3.5L V6 (rated at 278 HP) and variable displacement was faster and got better fuel economy. The Accord ran on 3cyl when that is all you needed. Problem with a turbo is you are always into the turbo and asking more air and fuel to get moving and stay at highway speeds. If you paid attention to the whole video they reason for these turbo engines is not really fuel efficiency but to get the EPA numbers higher. That does not translate to real world fuel economy. Ask anyone with an eco boost Ford Pickup.

[@Whyteeford]

Only time a small 4banger turbo gets better mpg than a 3-3.5L V6, is when your in bumper to bumper traffic. On open roads, your gotta rev up the 4banger turbo alot more to achieve the same speed. Therefore using more gas, the turbo is dumping more heat in ur cylinders.

[@scottxp800]

Turbo, no turbo, gas, diesel... If you drive it like a sports car you get sports car fuel mileage. If you drive it like an economy car you get economy car fuel mileage. Power takes fuel, use more power and you use more fuel. I have a 335i with a tune that makes 23 psi boost. But if I drive economically it gets 19 mpg city 29 mpg highway, when it's making 500+ hp (440 at the wheels) the fuel mileage is considerably lower :)

[@RWoody1995]

The problem is, I think you can go too far the other way. On the lowest end of the range you sometimes don't really get an "economy car" anymore, probably because compromises are made to make the base engine as cheap as possible and keep insurance down for young drivers who get fucked if they have anything over 1.2L, I drive a 1.2L ford fiesta at the moment and while I get higher MPG than people I see on forums who claim to be driving economically I still get less MPG than people driving the 1.6L engine seem to achieve, while i could probably equal/beat them i'd have to start impeding traffic to do it as accelerating with the flow of traffic *almost* takes "driving it like a sports car", only now its 1.0L T vs 1.4L N/A with more modern cars than my 12 year old fiesta :/

[@martinlang9615]

I had a Holden (Opel) 2 litre 4 cylinder diesel intercooled, manual hatchback (like a golf) and THE WORST fuel efficiency was 10 liters per hundred driving very hard around town. That is very very good economy.

[@Ziegfried82]

No matter how carefully you drive a V8 or V10 it's gonna be a gas hog. Will it be slightly less of a gas hog with granny driving? Sure! But then I gotta ask why the hell did you buy a car/truck with a big engine?! With a V4 or V6 turbo the granny driving actually brings a huge efficiency boost. RWood1995 makes a great point about underpowered cars though, if they are too weak they can be inefficient for highway driving. A key element of Scott Gaines example is having the custom tune on his 335i, what about the stock tune? Obviously custom tunes are gonna be better than stock, hell I'm using a Cobb tuner with an OTS map on my WRX and the fuel efficiency, power distribution and power is way better than the stock tune. 32 MPG highway vs the 27 MPG highway I got with the stock tune.

[@lang9872]

Could gasoline with a high octane number minimize knock and also minimize the injection of fuel to cool the cylinder temperature? It sounds like fuel consumption could also be significantly reduced at full load at downsized turbocharged engines. What are your experiences?

[@aldeacristian4582]

@Engineering Explained, your explanation is partially correct, a modern Tcharged engine is efficient at low and high loads, first way to reduce engine knock in modern forced induction engines is EGR valves, secondly water cooled intercoolers. I've driven 1.2 TSI Vw group car for 60.000 miles(company car), city, highway and mixed cycles, it got way better MPG then a naturally aspirated 1.6 MPI(equivalent power natural induction engine), both having around 100hp,

[@joshuagies4900]

Also the fact that non-turbo engines also use richer mixtures under load/to create power.

[@jaredgates4310]

Wow so basically when you are driving under normal highway conditions turbo 4 cylinders get great fuel milage but when you floor it to make boost/horsepower they make bad fuel mileage.... Surprise!

[@upsidedowndog1256]

My 85 Kawi 750 turbo motorcycle can get 45+ mpg steady state cruising at 75+ mph. Around town and under high boost that drops to about 7 mpg! Small price to pay for the fun though.

[@brendanvasser1]

2017 Chevrolet Malibu. 1.5L , When I set the cruise control at 65 I normally get around 43-47 on the highway. Now go to to 70-72 around 36-39. Having the A/C on “eco- car shuts off at red lights with A/C on.”will bring it down about 6-7MPG less city and highway. So far reliable! 73K.

[@rayberlin]

Why would anyone buy a turbocharged car and expect high fuel efficiency? I bought a turbocharged vehicle for its high reserve power from a small lightweight engine and drivetrain. That to me is efficient! I still enjoy reasonable fuel mileage by keeping my foot out of it. When I need a boost of power, it's there. I previously owned a naturally aspirated 1.6 L Ford Fiesta and I routinely enjoyed 40+ miles per gallon at 70 to 75 miles per hour but Ford was punished for inefficient drivers claiming that 40 miles per gallon was not obtainable and Ford had to lower the claim to 38. Why buy a Toyota Prius, drive it at 80 mph and complain about efficiency? The technology does not compensate for idiocy!

[@thetechlibrarian]

Right because you can definitely drive a regular car or even hybrid a certain way and get really good mpg

[@kevinb9407]

I used to drive the "turboed" vehicles back in the 80's (yes, I'm old), and it was the same deal back then -- you had to stand on the gas to get any power. Seems not much has changed since then.

[@SSChambers1]

The technology has changed for the better with more efficient turbo designs along with better cooling. But the main principle is the same. They're still a blast to drive but will drink fuel like an alcoholic when you put your foot down. They are designed to do this not only for the demand for more power but to richen the mixture so you don't lean out and fry pistons. One of my favorite turbocharged vehicles is the older Porsche 944. Primarily gutless but had power when you needed it. Not to mention, one of the easiest and smoothest manual transmissions I've ever driven.

[@rivahoff]

I was about to say it all comes down to power to weight ratio... But now that I've read many comments I got to say *it all comes to learn how to drive people*

[@daos3300]

nice! would love to see more on superchargers. tons of available info on turbos, comparatively very little on blowers.

[@bloqk16]

Turbo is nice to have when the vehicle is still under factory warranty. But once the expense of engine repairs becomes out-of-pocket for the owner/driver, watch out!

[@pauld.b7129]

Well the turbo itself is a wear part... But besides that not really. The pistons, rods cams etc are fine, unless those fail" your all good. Ive seen volvo turbo with 300k+ miles that never had an issue.

[@turboseize]

My car (with a turbocharged, downsized petrol engine) is out of warranty since about 32 years. The car has tons of problems - the electrical wiring is disintegrating, the body is rusting badly, and there have been issues with the drivetrain. For example, after half a million kilometres I needed a new alternator, and shortly after that the gearbox had to be rebuilt. But the engine itself is bulletproof. Small turbocharged engines CAN and DO last. All it takes is an owner with a minimum degree of mechanical sympathy and who does not neglect maintenance.

[@bloqk16]

@Martin Rudolph . . . I'm impressed with the durability of your vehicle's engine, turbo, and alternator. The half-million kilometers for an alternator is astounding, as here in the US, the average life expectancy I've had was around 161,000 kilometers when it needs replacing.

[@jammi__]

@@bloqk16 Simply stop buying American cars then. Here in Finland, we judge them as having roughly Soviet style build quality. Get Japanese or German instead, but avoid the Chrysler era Mercedes-Benz.

[@zipper978]

Modern turbos are very reliable. It’s old turbo designs that were not as reliable. Keep in mind semi trucks are turbo diesels with 300,000 miles or more

[@RockStarCrisis1]

My 2019 Jetta with a manual seems to do better mileage wise than expected with a 1.4L Turbo. Rated at 40 mpg on the highway, I've done a 45 mpg trip, recorded by the cars computer. Still fast enough to punch it on the highway as well, doing zero to sixty in about 8 seconds.

[@TheLeonardoRF]

Love this video finally answer my question about why i get better gas milage in a 2.5L L6 BMW than a 2.0T in a Tucson

[@jelanifane7530]

2.0 better gas 2.5 go fast

[@Ricardo_C]

I didnt buy a twin turbo 3.5 ecoboost for mpg , I bought it for power !

[@rogerk6180]

Ricardo Chavez high five! Boost is for fun, not economics. Got best of both worlds, v8 with a turbo on either side of it. Like driving a rocketship!

[@rangerrick1859]

If you buy it for power then buy the V8. The most reliable engine in the f150. Then you do not need to worry about the turbocharged headache of an engine in the future when it wears out

[@dpracing1]

This tutorial is 100% correct. With a small turbo engine let’s say a 1.5 liter, you’re constantly in a boost situation (even during light acceleration) and you will burn more fuel. I went from a 2.4 liter Honda Accord to a 1.5 liter turbo Accord and the average on the 1.5 is about 3 mpg worse than the older naturally aspirated 2.4. However, during steady cruise on the highway, the 1.5 is about 3-4 mpg BETTER.

[@robc8468]

It's all about "cheating the EPA" numbers in even on the highway in heavy traffic you can't run steady.

[@ICYUNVM3]

I see this a bit on the 2018 wrx. I have to downshift going up hill to keep it out of boost to see any decent MPG . Gearing in that car always keeps boost at the ready. Good for hooning in the twisties not for road trips lol

[@mobilePCreviews]

they're efficient enough as long as you stay off boost. my girlfriend has a veloster turbo and averages 8.0l/100km(30mpg) and that's with pretty much only city driving through the east end of toronto. Shes scared of the loud noises of revving the car out so she almost never goes into boost. ya a 1.8l n/a 4 banger would be more efficient, but it would also be ungodly slow when she wanted more power. the idea of the turbo is that you sacrifice a little bit of fuel economy to just have it there driving normally, but it's there if you want more power, at the trade-off of a bit of extra gas. but if you don't need the power it will still be better on gas on average than a bigger n/a engine making the same hp/tq edit: someone else said eco/boost. that's exactly what i'm talking about, if you drive it normally, you get eco. you want more power you have that option at the tradeoff of more gas. Maybe i'm just baffled by this, but does anyone actually think that adding a turbo makes it more efficient on gas?

[@ryanclark457]

dos Santos precisely, the key to high fuel economy in a boosted engine is to use boost as little as possible lmao. Lots of highway cruising geared for low rpms and you’ll easily have 30 mpg in a 2.0l turbo

[@cheshirecynic4524]

My Evo X is more efficient when I'm in the boost range, but it's admittedly a bit heavy for a 2.0L without the boost... I Best MPGs are in the lower range of boost (3000-3500ish RPMs), adding power without revving the crap out of it.

[@lsswappedcessna]

>Buys Veloster "Turbo" >is scared of turbo noises wat

[@NAGOSKY]

@@lsswappedcessna women

[@jaapfeitsma559]

8/100 is not very economical actually. Its a 'modern' engine with direct injection. Dissapointing really...

[@DS-xl2jb]

I baught last year a 1.0 TSI Skoda Octavia 115 hp, 200 Nm. I am verry happy with it, i don''t drive it fast until the engine oil gets to 60/70 degrees Celsius, i got an average of 5.8 L/100 Km till now, and that is excellent. It has 1150 KG without the driver, so the weight ratio is 100 HP/Tone which i think is enough. If people learn how to drive a gasoline turbo engine, everyone will see that is more efficient and fun to drive then natural aspirated gasoline or diesel engine(in my opinion).

[@MatthewTaylor3]

Boost is life. Fuel economy can remain an afterthought. 😎

[@rogerk6180]

eM BOOOOOOOOST. It is so addictive man. Best invention ever.

[@arthursutherland205]

Until gas prices go to $10/gallon

[@rogerk6180]

Arthur Sutherland it is allready here though. 1.80 euro per liter shouldn't be far of i think anyway.

[@Trades46]

If you drive like a street racer and punch the throttle all the time, the boost is always on = bad fuel economy. I manage to get 6.5L/100km average on a 200hp 2.0T engine all the time on a small hatchback, so not impossible.

[@rogerk6180]

Trades46 i do 19,5 liters per 100km average. Wooha lol.

[@KevBoy3D]

That is really good for 200bhp, you do mostly highway driving?

[@Trades46]

About 80% highway I would say yes.

[@al3oqab128]

I average 7.5l/100 km on my 1.2 TSI 110 hp ahahaha

[@martins5176]

6,5l/100km city driving, 6l highway, 12/15 track (1.5t chatch)

[@8__D]

This is a good explanation of why fords eco boost had valve carbonization issues when used under load. The rich air fuel mixture used to cool the combustion space resulted in incomplete combustion allowing soot to build up on the exhaust valve and eventually ruining the valve and it’s seat

[@mikerich32]

I don't know a lot about engines, so don't flame me, but would adding an intercooler fix the problem of engine knock in this scenario rather than relying on the rich fuel mixture to cool it down?

[@sukruthrajesh2378]

AERO BLKHWK32 I think even though ur using an intercooler, the amount of air in the cylinders is much higher and as a result the pressure is much higher. So, as pressure increases, temp increases........even though you are supplying cooler air.......

[@davemoore2972]

AERO BLKHWK32 Yes. An intercooler (if there's only one turbo, technically it's called an AFTERcooler) reduces knock. Video explains what happens when boost arrives and the ecu increases richness to protect engine. Premise of video is that we all spend >30% of our driving time with foot on floor. In most countries, this is drivel, as your drivers license will be gone before the contents of your fuel tank. Most driving is done with 0% to 15% throttle. Happy place for turbo economy.

[@swayingGrass]

Even with same intake temperature and compression ratio, as there is more air (denser) it heats up more when being compressed in the cylinder.

[@ForTehNguyen]

you can only cool it down so much

[@miagi1337]

He didn't mention it in this video but there is nearly no point running a turbo or compressor without intercooling the gas before it goes into the engine. Also the rich fuel mixture is there to cool the turbo mmainly at high rpm (we are talking about 800°C instead of 950°C+). We made some tests on the engine-bay and as we excellently forgot to turn on the "rich fuel mixture for cooling" in the software, the Turbo-Temp *quickly* went up to 850°C, 900°C is the absolute maximum that system may reach and that is rather over short times. The knock is a different problem to the overheating turbo that is cooled by rich fuel mixture. Cooling the exhaust gases before the Turbo with a intercooler is not easy and shall not effect the efficeny of the Turbo. VW has a watercooled exhaust connector to the turbo that tries to reduce the need of rich fuel mixture. EE already made a video about that thing.

[@DaPepster]

ANY engine with forced induction will be less efficient when under boost when compared to operating it during low idle and cruising conditions.

[@jamest.5001]

Water/ methanol injection will help it alot! With a free flowing intake and exhaust. Along with a cooler thermostat than the factory tends to use. Drop the intake air temperature. But large engines are more effiecent anyway. I wanna put a 3cyl or 4cylinder diesel in a 1/2 ton truck. Maybe a vw tdi diesel . with a compound turbo. So it can make low rpm boost. And higher end boost. Without restriction in the exhaust. From a small turbo! I'm sure you know a compound setup uses a small turbo fed by a larger turbo. So the boost is staged. The boost gets boosted. Along with water/ methanol injection. " windshield washer fluid" and a large intercooler. It should approach 80 mpg. With the proper gearing. Maybe better. (Overdrive ratios,tire diameter) the main thing is keeping the O2 density up while increasing pressure. Great video.....

[@strangeclouds7]

Reminds me of all these 1.4 liter turbocharged 4 cylinder engines that are in the Chevy Cruze etc. Makes you wonder how efficient they really are.

[@sneakysnakepie1]

StrangeClouds there're actually not that bad but it all depends on the location. Like weather, hills, etc

[@Westkhost]

StrangeClouds they're not. My wife has a 1.5L EcoBoost powered Fusion SE Nice car, a little bigger than I prefer but I swear on everything that I hold dear, I have watched the Fuel Economy hit 3.5 MPG when burying the throttle. For being a larger "mid-sized" sedan, the 1.5 does pretty well and perhaps in a small application could be a really fun engine but at times I'm certainly reminded that it's not my older Legacy GT. Though it is leaps and bounds more "Luxurious"

[@skurtov]

Owning a Chevy Sonic that has that same 1.4T. Its everything it's cracked up to be. I get 32-34 average with mixed driving.

[@Tonyx.yt.]

StrangeClouds Well... 1.4/1.5 still decent size, in Europe is plenty of 1.0 3 cylinder turbo engines, not only for small but also midsize cars...

[@jd-py5nm]

i owned a cruze and with that engine got 32 city and 37 highway so not bad and it was fun to drive thanks to the turbo and i live in a mountain state

[@timsmith854]

I appreciate your video but I feel that after owning over 30 different cars, I have a valid opinion. Golden rule: You can put a V8 in a small car but you cant put a forced-induction 4cyl in a family sedan. I had a heavy Chrysler with a 360 in it. Extractors, large exhaust and an aftermarket 4bbl. Perfect engine to shift this car. Was no traffic light weapon but heaps of fun doing burnouts and it did 125mph I also had a Nissan 97 200SX (same as your 240SX) with the legendary SRDET 2.0lt turbo engine. I did not crack this engine open. Just a new fuel pump, 3.0" exhaust, Chinese eBay intercooler, pod filter and a dyno tune remapping the factory ECU. ABOUT 1300 USD in total. I got close to DOUBLE the factory power atw, same with the torque. No crazy boost, pump gas and easy drivability with the a/c on during a hot Aussie summer. Both engines were suited to the vehicles they were put in. Although the Mopar suffered from heat sink thus high running temperatures and really needed after market cooling. But I challenge anyone to coax 50% more HP out of a V8 for around 1300 USD? The surprising thing was that the turbo engine was still easy to get around 350 miles out of 14.5 Gallon tank. On a pure HWY run I would easily get 385 miles out of a tank. I love all engines as long as they go quick or sound great or both. Oh and our 'government milage' stickers on new car windscreens ain't worth sqwat.

[@dimmacommunication]

Big cars need big engines , small cars drinks a decent amount even with big engines and do ok with small ones.

[@jamesgriego9729]

Knock is not from two flame fronts, multi-plug engines have mult fronts. Knock is from the hotspots you mentioned igniting the fuel charge before the piston reaches top dead center so the explosion force is applied to the piston while it is still travelling up.

[@dexterjsullen]

That's why I drive a twin turbo v12

[@vladlelcu5316]

Dexter Sullen 'TRUTH' what do you drive?

[@dexterjsullen]

Vlad Lelcu sl600

[@SoI_Badguy]

So... You mean biturbo?

[@Rickcrazy100]

sorry bud but I don't think your sl600 has a biturbo v12...maybe a N/A v12...but zero turbos on that old crap

[@SalvadorSTMZ]

This comment makes no sense. Same exact problem happens in any turbo fed engine, whether sequential or twin or single turbo v12 or v6. Problem is manufacturers are pushing engines to do more with less volume.

[@athalfridhu]

How to downsize an ICE: E100 Ethanol, low inertia turbo, variable compression (infinity), direct injection, plasma ignition, colder spark plugs. That is the way. E 100 eliminates knocking, low inertia turbo performs better in small exhaust ports, variable compression extracts the better efficiency for every fuel (TRUE FLEX) and every engine demand, Direct injection for efficiency, plasma ignition for faster burn with less advance and better cold starts, colder spark plugs to drain out combustion chamber heat... Electric cars are not necessary...

[@milchomarkov8158]

sounds like you want to drive your laptop

[@jayson657]

When I was leasing a turbo was fine. Now that I own, can’t go wrong with a nice large displacement natural aspirated engine. Mazda 2.5 L Skyactiv 4 cylinder here.

[@keny46]

The reason would be that people drive them harder. If you would drive it like a 4 cylinder without a turbo you'll still get decent mpg.

[@Ballacha]

as a "proud" 4b11T owner, can confirm the engine has a compression ratio of just 8:1, is slower than mobility schooter when below boost threshold, and gets 15L/100km or worse fuel economy. all that just for them 22psi factory boost (28psi on evos). glad technology has moved on.

[@Maxx2k8]

I have the Hyundai version of that engine. Can confirm, not efficient at all.

[@Ballacha]

Max Castillo isn't Hyundai using 4Gxx?

[@peterm3861]

That's why for example older Evos and Subies have ridiculously high fuel consumption. Rather big laggy turbo, high boost figures and low compression ratio. So most of the time you drive it like a N/A car because the turbo hasn't spooled yet in normal driving conditions but you give it more throttle because it doesn't move with it's 8:1 compression ratio and isn't efficient at all...

[@anthonywebber2211]

Discoloured Buttflaps 4B11T is different from a 4G63T

[@anthonywebber2211]

Discoloured Buttflaps, i was able to get 9.5L/100km out of my 2004 Chevrolet Impala, but on the other hand i was able to watch the needle on the gas gauge go down when the gas pedal and carpet were best friends lol

[@ze3bar]

i have a GM 5.3 L V8, tuned, with DOD turned OFF and i'm averaging 9.8 L/100 km highway 13.8 overall. very happy with it.

[@budaklapaq2885]

Mazda Skyactiv for life.

[@2dansonfan]

budak lapaq amen

[@littlerhino2006]

I might buy one new, despite my hate for dealerships

[@nickcaesar7650]

Those variable compression engines are extremely complex and has a lot of extra parts. Long term reliability will be interesting.

[@Mgoblagulkablong]

Toyota atkinson cycle hybrid even better.

[@littlerhino2006]

Nick Caesar pretty sure that's Nissan, not Mazda...

[@Connor4x4]

Ecoboost engines at least in the trucks get worse mileage and can't tow as well as a typical v8. Ecoboost are only good on paper

[@ecoboostedfuze]

I’m struggling with the fuel economy with the 1.5L ecoboost in my fusion. If I’m going for fuel efficiency I have to barely use any throttle lol.

[@daimon9]

I had a car with a 1.4L Turbocharged engine and the way I got around it was putting in premium gas. Everything normalized in the car once I started putting that type of gas in the car.

[@electrictroy2010]

I drioe Ford’s turbo-3 cylinder and got 70 mpg on the highway, so yes it can be highly efficient if you stay out of the turbo .

[@Transphoenixbiker]

Hey lookin to buy that same car. How many miles do u have and any issues

[@Transphoenixbiker]

Ya i know that much but how reliable is the engine?

[@dieselgeezer18]

@Deez Nuts manual transmissions are more reliable and cheaper to maintain

[@Fasttowpro]

In all the turbo builds I've done I consistently run an air fuel of 14. 7 to 15. 2 long as you can avoid high egts you're okay one thing not considered during the video which I understand why, is the timing of the ignition curve. Pre detonation can occur but if you set your timing more retarded as you advance RPM you can stay relatively safe depending on application. Also there are other remedies such as water meth injection that are great for keeping cylinders cool and adding power. Great video and very knowledgeable and if you guys want a main drift off what he's saying, the companies lie about their numbers lmfao!

[@R777-RLM]

I had a 2000 Jetta 1.8T, I took excellent care of it, but my best mileage was 26 mpg, worse than that was that over 80,000 miles, routine maintenance and lots of problems, costed over $6,000. Our new 2017 Camry 2.5L naturally aspirated 4 cyl. is getting 35 mpg.

[@R777-RLM]

@xHarux3 The Jetta was driven on the highway about 85% of the time, and only floored to pass on two lane roads.

[@chawenhalo0089]

Thanks for that. I could never figure out why most 4 pot turbo bangers with around 250-300 bhp used more fuel than my S54 inline 6 with 350 bhp.

[@PatrickRich]

Jason I think you might need to do a video explaining the engineer (protecting) benefits of sun screen.

[@berkk29]

Patrick Rich it makes your right front tyre rounder

[@mdfel1]

I went from a 1.5L Yaris (solid 5.9LPH) to a 1.2L-T Fabia. The Fabia can occasionally get down to 5.0LPH but any sign of traffic or high load and the economy dies. Also bear in mind it is infinitely more complex than the Yaris ie: turbo, liquid intercooler, regen alternator, idle stop, higher octane. I'm not convinced a small turbo was the way to go it is a bit more torquey but that's it. Great vid.

[@alimzia1]

Does this also lead to the emission of unburnt fuel at higher loads when more fuel is injected for the cooling effect?

[@noseefood1943]

ok, so nissan's variable compression turbos are on to something.

[@mikegirard4388]

My Honda Civic 1.5t is insanely efficient. Runs lean with no boost and gets 50mpg with a light foot. But yes, if you use all 170HP, you get that relative economy. Honda figured it out. I suspect the turbo location (integrated with the exhaust header) and some enhancements in head and piston shape make it work.

[@MrMacroJesseSky]

I always ride the thin line of great fuel economy, and lugging my engine in 6th gear at 1500 rpm