It Turns Out, Hybrids Are Really Hard On Engines

[@EngineeringExplained]

**Let's address the common questions!** *1) Does this mean hybrids aren't reliable?* No! Just because something is challenging or problematic, does not mean there aren't solutions to overcome it. Toyota has repeatedly proven hybrids can be insanely reliable, as discussed in the video. Good engineering can overcome real problems. In the car world, it's often thought that "simple = better" but you can have something complex and reliable (Prius), and you can have something simple and unreliable (ahem, you know who they are). There's a lot of fascinating engineering that goes into making these things run reliably. *2) Are the problems overblown?* It depends! As mentioned in the video, it's completely scenario dependent on whether you build up water/fuel dilution over time. Modern hybrids will have algorithms to address this as much as possible - with scheduled longer run times to help boil off water. For long distances, you can get temps high enough, consistently enough, to get rid of water/fuel. Even still, versus non-hybrids, you will see lower average temperatures, and short trips can exacerbate this issue (especially if the engine is turning on/off during these trips). *3) How do older hybrids deal with these problems?* Many ways! One of the easiest solutions to ensuring you don't have too much oil/fuel dilution is a shorter oil drain interval. Changing the oil is a guaranteed way of getting those fluids out. The more frequently you do this, the less of a challenge it is. Modern engines are calling for longer and longer oil drain intervals - the video discusses a product which is designed to handle these longer intervals reliably. *4) What about electric oil pumps; does that help with start/stop?* Sure, in many modern hybrids you have electric oil pumps - this can help provide oil flow prior to re-starting the engine. But not all hybrids have electric oil pumps; plenty (especially older hybrids) have mechanical pumps that only run when the engine is running. When you don't have oil flow, you're reliant on the properties of the oil - what film is left behind, as well as additives (like ZDDP, as discussed) to protect the engine in these scenarios.

[@jbaidley]

Does this go some way to explaining why Hybrids are substantially more likely to catch fire than pure ICE cars?

[@scott8919]

The amount of hybrids on the market going hundreds of thousands of miles on the original engine is proof automakers have enough measures in place to compensate for the issues raised here.

[@androiduberalles]

Wait you're saying like, the owner never does an oil change?

[@MoMCHa96]

​@@androiduberalles No. He is saying that there are more good sides to hybrids than down sides. So even if there are some issues, in general they are great.

[@aspecreviews]

4:00 I have a 2001 Prius, and when I bought it in 2020, I thought it idled after initial startup for a worrying amount of time. Turns out it just waits until it's completely warmed up (coolant and oil) to go into full operation and be able to shut off and start up at will. It will idle continuously until everything is warmed up to operating temperature, and only then will it shut off.

[@antoniocirino8444]

@@aspecreviews exactly

[@workingguy-OU812]

Agree - yet another video from this channel to be taken with a spoon of salt.

[@Duckferd]

As a engineer who has worked in PCV systems, the first time we saw the condensation/moisture problem from repeated starts was not in PHEVs and hybrids... but actually normal ICE vehicles in dealership lots. During the winter, we noted that some dealers would move cars from one side of the lot to the other side as they clear the lot of snow. Over 30-40 of these 'cycles', they end up with substantial amounts of water in the crankcase, and we had to instruct dealers to leave the vehicles on to fully warm up to prevent this happening. Typically in small amounts this doesn't cause an issue, but as you imagine, problems started to crop up when that much water has accumulated in the engine. This experience was really useful when we got into PHEVs, because we developed two things: a counter to force the engine to turn on after a number of 'cold starts' to force a warmup cycle, and then an algorithm to modify (shorten) the oil change interval minder if the engine is still not given the opportunity to warmup (say if the customer has constant short drives). As a tangentially related topic, moisture in oil is also how some oil catchcan manufacturers mislead, or at least inflate, claims about how well their products work. Today's PCV oil separation systems are basically like science experiments and incredibly efficient under most circumstances, but they do not filter out fuel and water vapour (those go back into the intake to be ingested). So when you see forum posts from oil catchcan manufacturers showing how much fluid they're capturing from street driven vehicles not subject to high G-loads, chances are that it's mostly water and fuel, and they never put that fluid into an oven to evaporate it and show you the true amount of oil they're actually capturing.

[@EngineeringExplained]

Excellent comment - thanks for sharing your insight! And yes, "lot rot" is certainly a concern for dealer cars that just get shuffled around and never warm up to temperature - probably has to be frustrating from the OE side to try and implement a solution!

[@dougdanzeisen9608]

Thanks Duckferd, I see the algorithm in my '22 insight. The engine runs continuously until warmed up to what seems like normal op temp.

[@MaxPwr176]

@duckferd thanks for the insight! Would you elaborate on why you excluded high G forces?

[@bennyang8049]

Thank you. At least i can rename my oil catch can as fuel&water catch can

[@57WillysCJ]

Funny I learned this from older guys back in the late 1970s. When only drove short distances during the winter moisture would build up, hence why mufflers rotted out faster so once a week you drove a long distance to dry out the engine and of course short times between oil changes. If you didn't there would be foam around your PCV and likely the carburetor. Take a drive of 20-30 miles one way and it would mostly dry out.

[@kevinbrown1368]

Love your videos but this one is just a little too connected to an oil company marketing its product. Hybrid engines are known to last a long time. My family owns three hybrids and never seen any signs of water in the oil in any of them. As you point out, oil sticks to surfaces keeping a level of protection in place and this is especially the case for frequent hybrid start/stops. Hybrids are also often managed to turn the engine prior starting to pre-lube it before turning on injectors and ignition systems. Finally, electric oil pumps are increasingly being used which can operate independently of engine rotation. So, Mobil is really highlighting a solution to an already solved problem to try to convince people to buy their oil.

[@audi_fanusik]

It all depends where u live .. if u live in tropical country where is low rain or very little moisture like in UK u good.. In uk is lot of air and water cars rusting and degrading faster...

[@Jordan-ql6tm]

Ridiculous

[@gijoeljamesmaldonado]

OK, so... NO EGGS IN THE ENGINE OIL. Got it.

[@EngineeringExplained]

Finally someone listens. 🤣

[@v8motors.]

@@EngineeringExplained But eggs in the radiator in an emergency...

[@vandorb12]

What about beans?

[@jonjonr6]

I thought the point was, for best eggs, cook them in oil designed for hybrid vehicles

[@justincase9471]

@@v8motors. Just wait for the tow truck to arrive.

[@funlovingJohn]

Toyota Hybrid engines use 3 phase veriable speed water pumps and oil pumps controled by the engine computer. Even though the engine may not be running the water and oil pumps are running while driving. So thats two reasons why Toyota Hybrid taxi's with 600000 are still running strong.

[@aspecreviews]

@@funlovingJohn my 2001 Prius doesn't. The only thing I hear under the hood while my Prius is idling is the inverter coolant pump and if it's on, the HVAC blower.

[@funlovingJohn]

@@aspecreviews The 2018 and up have no rubber belts, and the engine computer controlls everything to do with the engine.

[@MrD1maS]

The oil pump is driven by the chain. So if the engine doesn't run, then the oil pump doesn't run as well.

[@SvenTSchixe]

​@@funlovingJohn 2013 and up

[@Arman-tm1kz]

Nicely said, I'm a Toyota mechanic and we never have had issues described in the video. The only cars that usually do have mayonaise under the oil fill cap is usually on the ICE's and like 0.01% on the Hybrids. Long Live Toyota♥

[@saadalikhan4147]

My man has been hypnotized by Mobil 1 :( while all the challenges mentioned make Sense but they are not as major as explained. Besides that engineers also have taken these things into consideration while designing the engines.

[@singular9]

And yet toyota hybrids are THE MOST reliable vehicles in toyota's fleet of options. I know people who have 15+ year old toyota hybrids that have 300k miles on them, no battery replacements, and basic oil changes every 10k miles. Zero issues.

[@garyandtricia1]

But how many miles on the ICE engine?

[@micker9830]

@@garyandtricia1 What he is saying, is that you can go 300K miles in total and the ice engine will be fine, with all the starting and stopping, it's a 100% complete non issue.

[@raifparker3990]

​@@garyandtricia1Most of them are running on the original ICE. I worked at Toyota for quite a bit, routinely see older hybrids with well over 300k and all original

[@yootoobvyooer]

How many 15 year old hybrids on road? It's far less than gasoline powered even adjusting for numbers. Even with perfectly fine engine, dead battery means throw away due to high repair cost and only 1 year warranty.

[@garyandtricia1]

@@raifparker3990 missed the point, the ice isn't running the entire 300k is it? Probably under 100k on the ice.

[@aspecreviews]

Hybrids do not *cold start* their engines every time. My 2001 Prius waits until it's COMPLETELY warmed up to shut off initially. Ironically, that helps the engine stay off longer and under heavier throttle scenarios.

[@EngineeringExplained]

Yep, as discussed in the video!

[@adamkernohan]

..not all

[@carholic-sz3qv]

yeah ive seen some teardown video of the earlier prius and it literaly had like a kind of hot water storage or a heating system for the engine for it to stay longer in operation.

[@cooperp6429]

By completely warmed up, you must mean more or less warmed up. However it's kind of nice that the Prius has a small container for "warm" engine coolant, which is insulated, and when turn off your car, the coolant gets pumped into, so that it doesn't completely cool down. :)

[@nicmainville9954]

@@adamkernohanmind expanding on your "not all" comment or are you just being a contrarian?

[@GenghisKhanrad]

My dad has a Prius with over 350K miles and still going strong. He also has a Tundra, because life is about balance.

[@jamescreekmore3855]

Exactly one Tesla and one supercharged corvette! 😂 balance

[@Argedis]

I like your dad. I have a Mazda 3 and a Tacoma, completely polar opposite vehicles and I love them for it.

[@JanGoh-jb5ge]

My grandfather had a car for city driving, a big truck with a camper, and an SUV for hunting. It's honestly kinda foolish to have a single vehicle for everything if you can avoid it. Even a cheap used compact car for city driving will save you money and wear on your truck. It's absurd to see huge lifted pickups doing grocery runs with an empty bed. :/

[@garyandtricia1]

How many miles on the ICE as opposed to the elec?

[@GenghisKhanrad]

@@garyandtricia1 Hard to tell but I know my Corolla Cross Hybrid I just got shows me the percentage of driving that was EV only. That usually sits around 65-70% when I turn the car off. Mine is the new 5th gen hybrid system, so it's probably more than his. I'd assume his would be around 50%, so 175-200K maybe?

[@mschumacher1805]

A friend of mine from San Diego, is a Uber driver. His 2020 Corolla Hybrid has already 500k miles and the ONLY maintenance he's done was replacing coil pack/spark plugs and brake pads.

[@lanceareadbhar]

I assume the San Diego weather is a major factor as to why it's going so well for them. I would expect that they've done oil changes and new tires given the mileage. 2020 is also not that old and mileage used early seems better than the same mileage 15-20 years from purchase.

[@EngineeringExplained]

500k, that's incredible! Toyota has certainly figured out the reliability part.

[@kevinroscom]

​​@@lanceareadbharworking as a mechanic in CO, we see a lot of old Priuses in the 250k-300k range. I have had to do a few Prius batteries on some of those second gen ones, and I have had to do two water pumps, but most of the time you only ever see them needing oil changes and basic maintenance. Those cars really do last forever

[@mrfriz4091]

I don’t recognize the Toyota in the post but in my 2022 RAV4 0W16 required. 0W20 oil shown in video, odd I would say. Maybe he doesn’t look under the hood or read the manual

[@KanaalMTS]

n=1

[@MaxPwr176]

Ultimately- a low mileage car that spent it's life on short trips, has had a harder life than one with significantly more "highway" miles

[@林振华-t4v]

Yes, but lot less wear and tear on the chassis. Which the only thing you cant really replace.

[@Wordfishtrombone]

My 2013 hybrid is nearing 200k miles. It’s wild to know how much engineering went into making it last!

[@mlw19mlw91]

1:40 @1:40 Electric oil pumps are already a thing. So the parts can get lubrication before they start moving. Even the lowly Kia Optima employs an electric oil pump these days. Most of the issues raised in this video are mitigated already.

[@N0Xa880iUL]

Excellent point.

[@StormsparkPegasus]

Hybrids (at least the Prius), have electric oil pumps. These pumps are run before the engine is started, and generally while driving even if the engine is off. This almost completely avoids dry starts. I have not (yet) seen a non-hybrid that has an electric oil pump like this. Not saying they don't exist, I just haven't seen one.

[@Haploanddogs]

Basically all large diesel engines have electric oil pumps for the same reason.

[@coryfogle5353]

I know for a fact the 2005-11Prius's oil pump is mechanical. Fuel and coolant oumps on the other hand are electric.

[@Avetho]

@@coryfogle5353 I think another comment mentioned the 2012 or 2013 and up are all electric oil pumps, so you're right that older Prius models have mechanical oil pumps.

[@Redhawk24]

But do the benefits of a hybrid out weigh the negatives? Electric motors reduce the strain on the engine.

[@EngineeringExplained]

Good question! I think the result of much lower cylinder pressures really helps, these typically aren't engines that are pushing the limits. Again, most wear comes from start-ups, so the electric assist is helpful in that the engine runs less, but a good question as to whether that's enough to offset start-up wear.

[@Redhawk24]

@@EngineeringExplainedagree. There are many other benefits to hybrids as well. Keep up the good work!

[@jmk9065]

​@@EngineeringExplainedAlso they tend to work at a near fixed operating point, keeping the revs/load near the optimal efficiency island on the BSFC map, so the engine is less exposed to varying demand, apart from the entire start/stop cycle of course

[@jaisingh-do2sw]

Does this also apply to 12v or 48v Mild Hybrids ?

[@jaisingh-do2sw]

@@EngineeringExplained does this also apply to 12 v/48 v mild hybrid technology?

[@TheOne24115]

I have watched many of your videos but this was one of the worst. First. Why use the advertiser as source? Hard to take you serious then. Second. All points you say is what maybe can happen. But seriously you think no engineers has thought about these problems? It would be much better with some statistics to see if hybrid engines actually needs any more repairs than normal ICE. For example take a car model that exist as both hybrid and not hybrid and see if it possible to see any difference how often they need to be repaired

[@MurCurieux]

Well said, he’s just being topical as most people are going hybrid and he knows it will get the clicks.

[@omnimoeish]

Indeed everything I've heard is that hybrids actually have less wear on the engine, and the fact that hybrids don't need a starter or alternator, and barely use the brake pads, also hybrids have electric AC and power steering so they don't have as many belts to wear out. I can see edge cases where people who only make short trips that hybrids might get water in the oil more easily but in those cases non hybrid gas engines would probably be barely better and with proper maintenance its obviously a very rare issue.

[@robertwright8844]

"But seriously you think no engineers has thought about these problems?" At 11:50 he complimented Toyota on its long-standing reputation for building durable hybrids, so of course he knows the engineers have considered and mostly solved these problems.

[@zakm0n]

I'm only 5 minutes in and I'm already done watching. What a way to destroy your credibility. This whole thing sounds like anti-green propaganda, and the fact that he's got an oil company sponsoring it makes it even worse

[@MrErichuizer]

@@omnimoeish Agreed, my hybrid does not have belts at all!

[@ThunderBird80085]

I'm pretty sure that the main reason my maverick gets lower mileage in the winter by a significant margin is that the engine almost never turns off. Pretty sure they made it such that it keeps itself warm enough to prevent excessive moisture accumulation.

[@needles_balloon]

The engine also gets cooled much faster when running the heater!

[@bizmar]

Recent research has shown that Nutella is a bad engine lubricant

[@taffy4801]

The Goober has a nut allergy :(

[@omnimoeish]

I saw that video. Very compelling evidence there.

[@EngineeringExplained]

The more you know! 💫

[@jamestverde]

Source?

[@jwalster9412]

​@@jamestverde Look for 'i replaced my Engine oil with chocolate'

[@trudgemankPhD]

Sounds like a solved problem, but I like being educated about solved problems.

[@maximac1515]

Well, hybrid vehicles are in sell for about 20 years and are more popular than ever. I think that problems mentioned in this video were already solved by car manufacturers some time ago. Also generally I don't hear about hybrid vehicles breaking more often than gasoline only vehicles

[@albert15986]

It's more of a click bait video to steer the pot in favor of EVs.. it's been well documented that 20yrs old Prius 2 has been able to get well over 300-500k miles with minimal engine failure.

[@MrErichuizer]

Compared to cars that my parents-in-law and friends drive (ice), our maintenance costs (hybrid) is roughly halve... Draw your own conclusion.

[@Frank00]

I thought the same thing, im sure this is happening but on a small scale.

[@Mr-pn2eh]

I still love hybrids Toyota hybrid engines are designed to warm up quickly.

[@romanc.5074]

Yeah, they do.

[@ABYTE64]

hybrids are the biggest garbage. Either full electric or full combustion engine

[@SoulTouchMusic93]

Mine does really quick. I kid you not, a kilometer down the road the coolant it's up already. It's nuts. And it won't even use much petrol power when first started. It just keeps it at a high iddle and moves on electric in the first 30 seconds. Unless the battery is hot, that's when it basically has to use petrol to move until the battery cools off.

[@b0bsaget007]

I am a mechanical engineering student, and I drive a 2019 Ford Fusion Hybrid. My main commute is 85 miles in each direction, with about 90% of those miles being pure highway, so I have no real concern about the oil getting hot enough to mitigate the water and fuel dilution problems. That being said, now I want to get some gauge to show me the oil and coolant temperatures for my shorter drives just to observe for myself how they change for my specific situations.

[@N0Xa880iUL]

Interesting

[@matthewbeasley7765]

In many fords the instrument cluster can be set to display parameters. Hold the odometer select button when you turn the key on. If the display changes your car is one of Ford cars that does. Cycle through for something labeled "OILT" or similar and it will tell you the temperature. I've had a couple of Ford Escape Hybrids. The temps are not an issue. If the engine starts cooling down, it will startup long before the temp gets to where condensation would be a problem.

[@67daltonknox]

The original hybrid, the Prius, is one of the longest lasting vehicles on the road. There are plenty of Prius taxis with over 500,000 miles on their original drivetrain.

[@RickJohnson]

For cold or idle starts, Toyota addresses the first concern by spinning up the engine to about 1000 RPM w/ the hybrid motor-generator closer to the engine (MG1) before introducing fuel and spark. This, along w/ anti-drainback valves in the filters, helps generate oil pressure more quickly. They've also tried various methods of pre-warming or quickly warming the engine, from hot coolant stored in a thermos (2nd gen) to routing coolant through a radiator in the exhaust stream (3rd-gen), though arguably, both of those strategies were more for emissions than wear.

[@matthewbeasley7765]

Pretty much every hybrid does that. It's wild doing a compression check on a hybrid. You disconnect the injectors and "start" the car. It spins away at 1000RPM while you compression check.

[@Bryan46162]

The Prius has proven to be the single most reliable passenger vehicle on the roads for the past 2 decades now. Hybrids may present a few different challenges for engine oil makers but obviously their advantages, when it comes to reliability, far outstrip any drawbacks. Primarily, I believe, the ability of the hybrid to dump the majority of the work onto the electric motor is key. This means that the gas engine can sit in it's most happy place for longer and just purr along, not facing the constant surges in demand that is inherent in driving. Electric motors are very robust and can better take the accumulated abuse over the years.

[@marshallargenbright7796]

6:20 Mayonnaise Explained

[@EngineeringExplained]

13 years of making KZbin videos, all building to this moment.

[@NETBotic]

Perfect, now I can send this video to the people that laugh at me for buying hybrid oil for my hybrid. Thanks.

[@NotOftenPoliteGuy]

Don't forget to buy lawn mover oil, bus oil, truck oil, scooter oil, motorcycle oil, etc

[@N0Xa880iUL]

​@@NotOftenPoliteGuy Username checks out

[@leanderzulu3494]

As they should because the oil shown here doesn't even meet the application required

[@matt45540]

motorcycle oil, it's typically designed for 4-stroke engines that are not water cooled. Meaning higher temperatures, an revs . They also make oil specifically for small engines like lawn mowers and all of the ratings I.e. "sae" are for different types of engines@@NotOftenPoliteGuy

[@TheAdventureAuto]

Its nice driving an EV and not having to worry about all this cold start, oil flow, stop start crap.

[@Gazer75]

Still have to be careful with the 12V battery. They are even smaller in EVs as they are not running a starter. At least most modern EVs actually charge the 12V when you've plugged in to AC charge over night. Some early EVs did not. The car actually had to be on and the HV battery connected for the 12V to get charged. Most common reason for road side assistance for EVs in winter here in Norway is a dead 12V battery apparently.

[@TheAdventureAuto]

@@Gazer75 I had to jump the 12v so many times on my gas cars. Not once yet in 4 years have I had any issues with my EV.

[@ledzeppelin1212]

Yeah, this is why I went from gas car to EV. It was a good call. I still think hybrids are good for many people. Plug-in hybrids could be a good balance.

[@DearSX]

Battery in Prius is 80 times smaller than a Tesla yet it still gets half the mpg rating. Not bad. Also batteries are pretty nasty to create, dumping a lot of emissions into the world. Really an EV may never be better for the world than an efficient hybrid. We won't be converting our grid to clean-ish energy for decades more.

[@Bambarbia2447]

I went the other way, from Tesla MY to new Camry. So nice not to worry about astonishing depreciation, very high insurance and expensive out of warranty repairs. Tesla was crazy fast though

[@TheKiltedGerman]

I wonder what Mobile 1's aim here is given how many and how long hybrids have been running reliably on the road. Missing the forest for the trees video.

[@jamesphillips2285]

Many automakers are pushing hybrids instead of full EVs. So Hybrids are expected to be a growing market.

[@Argedis]

@@jamesphillips2285 Tell that to GM/Ford/Kia who tried rushing the EV market. Hybrids have always been the answer and Toyota has been on top of that segment.

[@TheBeatenPaths]

I saw the forest.....perfectly.

[@peteranderson037]

To sell their brand of oil, obviously.

[@jamesphillips2285]

@@Argedis Toyota was the early entrant into the EV market. Their RAV4 EV was sued out of existence after Chevron bought up the NiMH battery patents. I believe the Tesla roadster used an overly complicated battery pack, with hundreds of commodity 18650 Li-ion batteries, as a patent work-around.

[@wileymonair]

My dad lived a 1/4 miles from work. He drives his SUV there and back and nowhere else often. He doesn't really drive anywhere else. He thinks he can still change the oil at 5k miles. I told him Atleast once a year minimum. Probably should go 6 months instead. Oil is cheap.

[@pooyakhalili406]

I love the way that the videos are super technical yet easy to understand. Thanks Jason ❤❤

[@EngineeringExplained]

Happy to hear it, thanks for watching!

[@terryboyle]

thanks for this, passed it on to my son who has a hybrid vehicle.

[@michaelnoah3795]

Many people saying “but Prius is so reliable”, That’s why only Toyota/Honda are being reliable with hybrid vehicles because they have so much experience doing this, meanwhile Hyundai/Kia/Jeep is already having endless power train failures on their hybrids.

[@checito2742]

Oh boy. At 1:51 he knows what he's saying is wrong; that's for a cold start. That means an engine that hasn't been running. He's standing next to a prius. Those things are on the rode for 200K minimum. Dude, you know better.

[@ValdrVideo]

He spends the full two minutes after that explaining that those numbers are about cold starts and not an engine that's been running.

[@EngineeringExplained]

Did you watch? Everything you mentioned is discussed in the video.

[@ephgee1554]

I used to work at Walmart Auto Care Center, and we had many prius's with over 300k, some with 350k, and still chugging along. Some were better maintained than others, but all still sounded fairly good compared to other cars with 300k. On an unrelated note, we had a Ford Explorer with 300k miles that had probably 12 quarts of oil in a poor v6

[@Drewcardello]

Damm! I fill my explorer v6 with 5 quarts

[@lincolnsampaiobr]

And them the manufacturer puts oil change intervals in 15-20k miles ... and he doesn't even talk about fuel dilution that occurs in each "cold" start-up ...

[@aaronbritt2025]

Mobil 1 sponsoring this video and having you feature their oil, when other oils might perform as well or better kinda gives me the Icks. I look to your channel for unbiased engineering reviews.

[@EngineeringExplained]

Just FYI, Mobil 1 isn't the only company that develops/sells a motor oil specific to hybrids. It's an understood challenge with understood solutions. I have a ton of oil related videos on my channel, and they've repeatedly lent their expertise to help answer the common questions. That said, I completely get the skepticism - I try to keep anything sponsored fact based, rather than subjective, so you don't really have to question my intent. We're all here to learn!

[@Rattlefish11]

This is likely a bigger issue in PHEV vehicles. For example, your morning commute requires a highway merge. The battery can in some cases be insufficient to safely navigate a short merge area. The engine is tasked with supplementing the power required to negotiate this merge. A cold engine is immediately required to produce power before the oil has a chance to lubricate properly.

[@ALMX5DP]

I've always wondered about that situation, and had concerns about PHEVs in particular not having enough motor output for such situations, even if that might be slightly less common.

[@EngineeringExplained]

Yes, and in that case it's immediately going from cold to high load!

[@toninhosoldierhelmet4033]

oil pre heaters and a auxiliary electric oil pump could go a long way, too bad manufacturers want to save every peny possible.

[@sridvan]

1 min before the merge put the car on sport mode. Until the merge oil circulates and everything is fine.

[@critten9]

@@EngineeringExplained I run a lexus PHEV and i dont have problems on EV alone power to accelerate/pass cars. If you are a high speed driver - probably shouldn't be into PHEVs anyway!

[@ArcherWarhound]

As much as I freaking love my Prius, and genuinely think given the age of it and so many others still on the roads that Toyota has sufficiently mitigated the issues mentioned here, this video confirms my opinion that Edison Motors design of a Diesel generator charging a battery pack for a fully Electric drivetrain makes loads of sense for getting the best possible performance out of synergizing both systems.

[@matthewbeasley7765]

A fully series hybrid is by nature much less efficient. Losses in a generator, two converters and a motor is much higher than in a gearbox. TRW invented the power split device initially used in the Prius and now used by just about every hybrid out there. They send most of the power through just gearing at freeway speeds.

[@hadtopicausername]

I remember on my old aircooled VW Beetle, if I did lots of short trips during winter, a certain amount of very mayonnaise like sludge would form on the inside of the oil filler cap. It would disappear after a long drive.

[@BikeFromTheBrink]

It comes as no surprise. Hybrids also use smaller engines which need to work harder. Many of my workmates chose hybrids as company cars as they didn't want to commit to full electric. They are only getting 30-35 mpg(UK) long term. Yet the 2.0 diesels we used to have did 68mpg(UK). Personally I had a 2004 E220 diesel, it did 52 mpg(UK) on my daily commute, later I had a 2014 E300 hybrid, same engine and only 42 MPG(UK) on the same commute. I went full EV for my company car now, but only due to the tax breaks. Still have a V8 for smiles at the weekend, and of course, the Cortina with 1.6 pinto.

[@rowmacg]

I just bought my first hybrid a 2024 Maverick, what a wonderful truck! I have been averaging about 45mpg per tank of fuel!!! That’s actually 3mpg better than the 42mpg EPA rating for city driving. I realized pretty quickly that it’s probably not good to start driving down the road in electric mode, and then the engine turn on under load while being cold from sitting overnight. Now I turn the gas engine on, and let it run for a minute before driving. I also put the truck in sport mode for the first 5 minutes or so, until the engine warms up. In sport mode the truck will not go into electric mode, once the engine is warmed up, I switch it over to eco mode to maximize electric driving. I have periodically checked the oil cap for that milky condensation, but it’s always very clean, so this method seems to be working well. I have been using Valvoline hybrid vehicle motor oil, to help suspend any condensation that could develop from hybrid operating conditions. Thank you for all your informative videos!!!

[@anthonyc1883]

A frustrating and concerning aspect of our Prius Prime, the plug-in version of the Prius, is how the cold gas engine will suddenly spring to life for the first time of the day after the all-electric power is depleted (usually after 25-30 miles of driving). This can happen anywhere under any circumstance, whether slowly moving through city traffic, cruising fast on the expressway, or accelerating onto an on-ramp where high engine revs are needed. Yes, it is possible to force the gas engine to run for a few minutes at the start of the trip to lube everything up if you know you will be driving beyond the all-electric range, but how many Ptime owners know to do that?

[@DrivingInFocus]

Piston rings are the no.1 source of wear, this has been reduced on modern engines with thinner rings, crankshaft offset from bore, better oil and pump designs. Start/stop is on most new vehicles because of emissions and fuel consumption.

[@AmericanRoads]

As AMD (The Car Care Nut) has repeatedly stated, change your engine oil every 5,000 miles or 6 months.

[@rockymountainjazzfan1822]

I've owned my Prius for over a decade. My Prius engine runs like brand new. Zero oil use between oil changes. I don't think that hybrid behavior is causing the engine wear--it's the fact that hybrid vehicles tend to be driven on short trips, but owners don't change the oil more frequently as that type of duty requires. I use good quality 0W-20 synthetic oil and change it at 5K mile intervals. Also, the Toyota hybrid engines are specifically designed to warm to operating temperature very quickly and maintain that temperature well once the engine reaches that temperature. Of all the manufacturers, I consider Toyota/Lexus as the only manufacturer that has gotten their hybrid engineering "right" all the way around. I would not hesitate to buy another hybrid from Toyota.

[@mungojack]

Brought to you by Big Oil

[@raybod1775]

Yes, but big oil are the only ones.

[@TurboHappyCar]

I only buy sustainable fair-trade single-origin batch-fractionation oil from minority owned businesses.

[@deurkl]

With the Volkswagen hybrids, the big starter generator (27HP) starts the engine at a higher RPM for a very short time and then drops it before putting load on the engine. The cylinders are also coated with some kind of Teflon.

[@ThisOldChris]

We also see this in ICE car when you work near where you live. The engine never gets warm enough.

[@vvevvevvvv]

11:56 300-400k miles is not much.Older Priuses and hybrid Corollas (also Auris) used as taxis have like 450-600k miles on them with the factory battery! Here in Poland a lot of Priuses are also converted to run LPG, which is 2x cheaper per liter than a regular gas.

[@ManuelFresh100]

The key to making these cars last is to drive them a lot. It keeps the battery healthy. If you have a long commute to work everything, hybrid is the way to go.

[@josephn944]

@@ManuelFresh100especially if you are frequently in traffic. The benefits of hybrid are maximized if you have to slow down / speed up frequently during your commute

[@CliffWarren]

I think you've just given me a good reason to drive my '07 Prius hard! I'll make sure to get that engine temp up there! 190K miles, runs like a champ and 50+ MPG.

[@georgeelder8415]

I keep mine in power mode all of the time, to help keep the engine oil warm...

[@needanameprojects]

Gotta love the industry for creating a world where I can buy an 08 Honda Fit and 07 Toyota FJ and just use them normally as family cars both approaching 300k miles. What a breath of fresh air from throwaway tech!

[@JSFGuy]

Beavis, he said hard on..😁

[@JNX07]

heh huh heh, hard on heh heh 🤣

[@digitalzomb]

Huhhuh huhhuh. Hard on.

[@somewhat-similar]

hnnngggggg hrrrrrhhhhhh hu hu huh

[@David_Crayford]

Well done. An engine for giving you a hard-on. 7 / 10.

[@mbiker345]

man, those Prius are really good looking cars.

[@EngineeringExplained]

They really are! Incredible how much of a turnaround their design language has had, they look great!

[@SovaKlr]

1:30 in I've got the solve already. Electric oil pump, constantly circulated with a valve to allow it to be used as a "cooler" for the hybrid system in order to keep the oil (and to a point the engine) temps up. I'll leave the fuel problem to someone else.

[@kipkipper-lg9vl]

or just use a diesel engine and avoid all this nonsense

[@overtoke]

there's a post on reddit today about a 2008 prius with 400,000k miles. my 2008 has 170k. it currently has a leak inside the brake actuator, but the engine works well. the battery has degraded but still works well.

[@larry4fire]

This video illustrates why the propulsion architecture of the Chevy Volt was such a brilliant idea. It operated as a pure EV for the first 40 miles or so before converting to a hybrid. The pure EV range was enough to satisfy 80-90% of the average driver’s trips, so no frequent ICE cold start’s incurring the problems you describe. If driven beyond the pure EV range, the ICE is fired up to turn a generator to develop the average electrical power necessary for propulsion. So on long trips the ICE tends to operate in a steady state fashion. In stop and go traffic the ICE does shut off frequently but the vehicle launches in EV mode before restarted the ICE smoothly and quietly with one of its two motor/generators. It’s important to note that in hybrid mode, once started the ICE is on most of the time and therefore warmed up and well lubricated.

[@jamesengland7461]

Meh- sort of. Volt was based on the Cruze, but when it was introduced, after the Prius, it actually cost MORE than buying a Prius AND a Cruze! There are claims that it actually cost GM DOUBLE the retail price to build each car. So... maybe there are less expensive solutions.

[@g.tucker8682]

The wife and I love our Volt. It charges overnight on 110v. We never plug in to a chargepoint, too much trouble. Just gas it up and go. We get phenomenal mileage. No trouble yet in six years. The one quibble I have is cargo capacity and the liftover rear hatch. Not bad, but was used to the Prius before I got sideswiped/totalled.

[@j-mo3129]

Sounds like we will be seeing electric oil pumps that could run before the engine is started

[@matt_d7828]

Rented a 330e last year and what I did before each drive was to set the car in sport+ to warm the engine up so that it will be ready for those high load highway merges. And for local driving, I relied on the electric motors only. Such a nice driving car. My first taste of driving a plug-in hybrid.

[@imzjustplayin]

Meanwhile in my '02 corolla, 10 seconds after turning on the engine, I'm on the freeway doing freeway speeds. My reasoning? on cold start the engine is doing about 1500-2000 rpm at idle. When I'm cruising on the freeway, I'm doing about 1800rpm. If I accelerate onto the freeway at less than 2000rpm, then the load on the engine isn't much different than at idle. It only takes about 30hp to cruise on the freeway. I've done this for several thousand miles, it hasn't had a negative effect on the vehicle at all. The car currently has 209K miles.

[@matt_d7828]

@@imzjustplayin I’ve had a 2010 Corolla which I religiously warmed the engine to operating temp before driving. I know how reliable and solid Corollas are. I’m not here to compare apples to oranges. I’m just stating that new cars drive so well that even less experienced drivers will likely not even notice. Nice that you take care of your 02 Rolla. I know it will give you many more years of reliability.

[@3akoscielski]

"So, that's why I've started making my homemade mayonnaise with Mobil 1 oil!"

[@EngineeringExplained]

Hahaha oh no please do not drink it!

[@subwhiffy02]

I've seen a 2022 toyota sienna with 250k miles without any issues, which is surprising considering that last generation sienna starting to have issues on lower control arms, timing cover leaks or rear main seal leaks when its at certain milage ( commonly at 120k+ miles ). besides doing a maintenance like oil changes and so on. it is a solid car, the only thing for me is that im not sure if this sienna that I've seen had been changing oil every 10k miles or every 5k miles because i have didn't bother looking at the history of this car unless there is a issue.

[@lomein2186]

I dont want eggs in my engine oil? Everything says i need eggs in my engine oil

[@EngineeringExplained]

No eggs in your engine oil!!

[@GoTigas]

I have a 2022 Corolla Hyrbid, enjoying it so far. Im definitely very interested in how it holds up over time with all the start/stop. I highly recommend people to use cruise control on the freeway so that the engine runs on the freeway. My car will try to go to EV mode with light throttle under 75mph without cruise control and depending on the traffic you can start/stop way to often on the freeway.

[@sf7234]

Putting a sandwich over your tailpipe helps absorb the unwanted mayo

[@TurboHappyCar]

Forbidden mayo...

[@ryanp135]

This is why Porsche, Land Rover, Bentley, Ferrari, & Audi are telling hybrid owners to, at least once a week, put the vehicle in " sport" or " sport + " mode to keep the ICE running and heating up, and drive it on the highway for at least 35 mins with the engine above 2,000 RPMS so that all fluids get hot and stay hot to burn off condensation and environmental containments, which will also burn off carbon buildup on catalytic converters. All engines should run for an hour of more every week or expect issues. This Hybrid, plug-in hybrid, EV push is only a 1/8 baked idea, it still has a min of 15 years before companies figure things out, then it will be another 10+ to get close to a viable solution. ICE engines & oil & diesel and & gas will be pumping for 3-4 more decades at least.

[@dankgankster4100]

Imagine, if you will, my happy place. A place where all the vehicles have an inline 6, rwd, and nothing unnecessary

[@jaggerdfletcher1618]

Amen 🙏

[@thijs5931]

N/A inline 6, RWD, Manual

[@dankgankster4100]

@@thijs5931 with optional 4wd of course

[@Mahoujanai]

One thing I noticed in other cars about the engine shutoff is it's really hard on the 12v battery. It has to be replaced more often.

[@alex548554]

That's not a concern with most hybrids, they use the electric drive motor to start the gas engine not a starter motor. There are some that still used a starter motor I think but Toyota most certainly uses the drive motor to start gas engine.

[@Drewcardello]

@@alex548554fords and Honda also use high voltage motor to start engine too.

[@Rambleon444]

Oh no, my Prius with 243,600 miles is prematurely wearing out with cheap Costco synthetic oil. What to do?

[@EngineeringExplained]

What do you mean? As discussed they can last with regular maintenance - good on ya for staying on top of it!

[@HEMI345S]

It was proven so many times that Costco branded synthetic oils are no inferior to brand names oils that clueless people are wasting their hard earned $$$ on 😀😀😀

[@benjamineastman9429]

​@EngineeringExplained OK, but then why is this a video about hybrids if the lesson is to maintain your engine (which is way below your personal paygrade in my opinion. )

[@imzjustplayin]

Is this a sarcastic post? If you're really concerned, get a used oil analysis test. If you buy a quality vehicle and maintain it regularly, most people chuck the vehicle before the engine gives out.

[@Ntmoffi]

​@@imzjustplayinhe's probably being sarcastic because this video is showing off Mobil 1.

[@erickbernard8208]

Your fuel type matters too, E85 pulls moisture from the atmosphere too, methanol is even worse, its best to run gasoline when storing/not driving

[@tdmap2241]

I am planning to buy my first hybrid. Lexus UX 300h F Sport to be exact. I was afraid this video was going to turn me away from hybrids. Thanks for the explanation of the mechanics behind this technology and putting me at ease at the end of the video. I am getting my UX next month.

[@matthewbeasley7765]

I can also state from personal experience that this isn't a problem. I had a 2006 Ford Escape hybrid. I put over 250K miles on it, then gifted it to my daughter. She's still running it at about 330K. Still the original battery. I now have a 2012 FEH at 270K, still going strong. There is no sludge tendency in these engines. I've had sludgy engines, but not these two for sure. On factor that EE isn't considering is that the load on the engines is much higher in a hybrid. The power always comes from the gasoline, just over a shorter engine run time. The engine is off when there is no or light load. When the engine does start back up, it often has to recharge the battery. This means the engine runs under more load as the battery catches up, adding more heat.

[@JordieG8]

I’ve done oil analysis on my last 2 oil changes on my Kia PHEV. The first one had a fuel contamination of 5.2 percent. Crazy high, almost pointing to an injector leak. For the next oil interval I made sure to run the engine harder once a week to get the oil temperature up and boil off any water or fuel. The next oil analysis showed zero fuel in the oil. Lesson learned, make sure to run the engine a bit harder from time to time.

[@yayitsjepoy]

I was kind of confused by the title at the beginning, its early here on the west side lol. but, I didn't know about the water in hybrid engines, so I forsure learned something new today. thank you always :)

[@louisstennes3]

Good video. Learned a lot. My wife's RAV4 Hybrid XLE gets high quality oil changes (SP oil) plus high quality WIX filter every 5,000 miles. No problems. Manufacturers telling you 10,000 mile oil changes are the problem. Yes if you put in fresh oil and filter and drover across the country three consecutive times, you can get by with a 10,000 mile oil change. For the rest of us if you don't want to buy a new vehicle at 75,000 miles, do 5,000 mile oil changes.

[@enzomatos2307]

Jason's work in this channel keeps amazing me at how entertaining and educational he can be, a great online teacher for engineers (and curious people) all around the world!

[@marcinmerrimack1726]

Seeing him product shilling now is disappointing.

[@Ollie2846]

Thanks for explaining hybrids in a way only you can. I always feel I learn so much from your videos, even if I don't fully understand everything.

[@pnw_jordan]

I’m never going to understand why hybrids don’t work like locomotives. Essentially, the combustion engine is a generator completely independent of the drivetrain. It feeds electricity to the battery, which then powers an electric motor, which is what powers the wheels. This allows the engine to run at its peak efficiency all the time.

[@EngineeringExplained]

Some do! Series hybrids work this way, parallel hybrids do not.

[@zacksstuff]

Would require a bigger crankshaft motor/generator and a bigger drive motor, both of which weigh and cost more. Toyota gets away with fairly small motors on their hybrid setups because the engine is there to help provide full power.

[@TheEquationSlayer]

Honda’s current hybrids work like that (serial hybrid). The engine only connects to the wheels when cruising at highway speeds. Very simple design with no real “transmission”. But since it can’t vary gear ratios, it’s less efficient than Toyota’s system at higher speeds (like 70+mph).

[@SniperSnake50BMG]

All of that after solved by several Chinese New energy manufactures. Look a little to Li Auto, Yangwang among others more affordable

[@robertbutsch1802]

Locomotives don’t have drive train batteries that amount to much do they? The electricity gets generated by the diesel motor/generator and goes straight to the traction wheels I think. Diesel-electric locomotives can’t power away from the yard after sitting a while strictly on battery power.

[@Mrblueridgeman]

I had two Toyota Camry Hybrids. First one was rear ended and totaled at 169K miles. Engine was like new. Never used oil and never gave me trouble. I traded the second one at 150k only because wife wanted a German suv. It was still mechanically perfect. I changed oil every 5K with synthetic.

[@superjesus4307]

PHEV are more issue than traditional hybrids because they keep the engine off until power is actually needed. HEV usually warm up the engine right away unless you press an EV mode button. Toyota's and Honda's 200k+ mile consistent reliability proves these issues either aren't really a problem or engineers have accounted for them in the design. What we really need are turbodiesel hybrids. This will give the great hybrid economy in city/mixed driving but great engine economy AND power for highway/long distance travel. The turbo oiling issue can be easily overcome with an electric oil pump, like Toyota does to lubricate their transmissions. The issue with efficient NA gassers on long trips is they like to revv their nuts off when any amount of power is needed, can't be having that at 80mph for hours.

[@zibingotaeam3716]

oil is not the problem with cold turbos, they get oil just fine. The problem is that the oil is exposed to exhaust because the turbine is cold and thus hasn't expanded to its operating size yet. Its especially a problem on petrol vehicles, because the turbo there hits up to 1200°C, with Diesels being somewhat cooler, but its still several hundred °K that you have to account for in design. exhaust on the oil means it cokes up/carries a lot of soot, which then blocks the oil passages in the turbo and it subsequently dies of oil starvation because the engine can't deliver oil pressure through blocked passages. TDIs aren't nearly as efficient as you'd think. Diesel is just a lot denser, so when you measure it in volume, you need less, but when you measure it in weight, fuel consumption becomes only slightly skewed in favor of the diesel by a really marginal amount. The main problem is that with emission regulations, you can't have high diesel compression ratios because that produces a lot of... unpleasant... NOx gases, and compression dictates your efficiency in a major way. So ultimately I'd argue that a PHEV with an engine setup that intends to use the ICE for long distance travel exclusively and the EV part for city driving almost exclusively is ideal. Now, if you told your car through the navigation software about your planned route, the car could optimize its power strategy accordingly and you would end up never overtaxing any component of the system.

[@1HeatWalk]

Amazing video! I didnt know making engine oil was so complicated. I will have more appreciation on these prodects from now on and realize there are differences between motor oils.

[@ittimjones]

For anyone curious, LSPI is a big killer for Fords Ecoboost engines. Use good oil, and change it regularly and BEFORE the recommended intervals.

[@Drewcardello]

Every 5k miles should be changed in ANY vehicle

[@ittimjones]

@@Drewcardello I have evidence saying otherwise. I have a Focus RS. I sent a sample of oil to Blackstone with 1 year and 6k miles on the oil. They responded with extending to 7k miles between oil changes would be absolutely acceptable. I used to change my Focus ST oil at 7500 miles, and I didn't have any issues (with a performance tune) out through 150k miles when I traded it for the RS. It really depends on the vehicle. My Silverado on the other hand actually feels sluggish if I go past 6k on oil changes.

[@ManuelFresh100]

2011 Prius with close to 300K miles here. Still runs like a champ

[@MrPruske]

Paid for by literally big oil. Imma take this with a bit of salt

[@jamesphillips2285]

Salt also damages your engine!

[@zacksstuff]

My 2010 Prius has 135k miles on it now and it hasn't given me a single issue. Most expensive single part that's been replaced so far is the spark plugs.

[@ABYTE64]

135k miles XD? Do 600K

[@zacksstuff]

@@ABYTE64 working on it, give me a few decades.

[@ABYTE64]

@@zacksstuff bruh, it wont do it

[@JMNTN]

i always wondered how engine wear is on performance oriented hybrids because they usually kick in the engine when on full throttle so it cold starts and immediately gets hammered.

[@EngineeringExplained]

Yeah, basically the toughest scenario! If the oil is already hot, it can get circulating very quickly, but if it's cold it's a challenge.

[@Themitch343]

It’s one thing: 🗣️MaYoNaIsE

[@danielboudreau6680]

Why are you using 5w20 and 5w30 while using a M20A-FXS engine? This engine exclusively uses 0W16…. You also didn’t mention the selective coolant valves that are also unique to that engine family that can together with the thinner oil remedy the issues you talked about. Basically, you used the technology that addresses the problems you mentioned, as a tool to demonstrate those problems without pointing out that specific car and brand fixed those problems

[@LAG09]

They say that a full on cold start at below freezing temperatures puts on about the same amount of wear on an engine as 500km (300 miles) of driving. Because of this engine block heaters are legally mandated standard equipment for cars sold in northern Europe. So over the long term, even if its not this kind of cold start, additional engine wear on hybrids is obviously no joke.

[@chrisw.2492]

So does the stop/start function on ICE only cars also cause extra wear on the engine? Note: I'm not an engineer.

[@leviathan5207]

Yes it does. Why would it not?

[@bing-chilling1713]

yes, id say that so much so that it's not worth turning that function on. ac needs engine power.

[@Neodymium5312]

Yes it does because the main bearings and crank bearings do not have oil pressure up to a few seconds into the cranking and starting procedures. If you have oil pressure the bearings do not actually touch the shafts when you have no oil pressure you get wear, every time you start an engine you're going to get a small amount of wear because you do not have oil pressure yet, more starts means more wear. In industrial engines we have a pre-lubrication pump that sends oil up into the journals and bearings before the engine even rotates, and gives you oil pressure because the engines are so big and heavy that they cause extreme amounts of where when there is no oil on the journals and the cranks are so heavy that they push the oil out from underneath them and you do not have a film to protect the bearings without oil pressure

[@florian_d]

Yes it does. As does driving only short distances.

[@EngineeringExplained]

I think it's common to assume it's hard on the battery/starter-motor, but obviously these are sized appropriately, and as for the battery, most start/stop systems will only activate if the battery charge is high enough. Otherwise, the engine remains on as the battery continues to charge.

[@KonaBlueSVT]

It is also highly dependent on driving habits and is exaggerated by plug in hybrids (PHEV). Someone that drives their hybrid at highway speeds, is likely getting the oil up to temperature regularly. The vehicle that lives in town, stop and go traffic, short trips, etc. will have way more of a problem with water in the oil. The misconception is you either don't have a problem or your car breaks down. These are not mutually exclusive. You can have an issue that is slowly affecting wear, without knowing it. Preventative maintenance is key. All fluids and parts have a useful life and if you exceed that useful life, there will be wear.

[@kitehman]

Oh boy, your community engagement metrics are gonna be off the charts for this video 😊

[@rtroyer8963]

Great explanation on the condensation problem! Cheers!

[@danielgiesbrecht7448]

It's fun to watch a video that's so conceptually accurate, but not at all true in practice. Way to create unnecessary anxiety! Dear hybrid owners: Just keep doing what you're doing, and don't fear anything you heard "Engineering Explained" explain.

[@diwulechao]

I have a hybrid. And yes I have both water in oil fuel in oil problems. One easy way to check water in oil is to check your oil fill cap.

[@MidnightMustang]

I'm not sure how this was a surprise to anyone at all, it felt like this was pretty obvious straight from the get-go.

[@russh6414]

Great Video and explanation! And this is why I only use OEM oil in my 300k mile 2nd gen Prius and keep it regularly maintained.

[@saop94]

But toyota recommends 0w16 and i only see mobil 0w20

[@MaxPwr176]

Right! Our manual states 0-20 may be used, but must be changed to 0-16 at the next interval

[@howebrad4601]

To those folks complaining about advertising, get over it. Just because a company helps provide data and support doesnt mean the claims made arent also true. I find value in getting info like this even if its source was an advertiser. If the company itself is reputable most likely the accompanying info is also reputable

[@tiagoadcosta]

i don't know in general terms but Toyotas are really great and have a series of advantages in terms of durability on hybrids. I drive a super rare (specially in Europe) gen 1 Prius nearing 200.000km and it drinks absolutely no oil between services. It's still on original water pump, disc brakes i don't think won't have to be changed for another 200k, and disc pads were just changed at 190.000km. And that's with 5w30 oil, which was they recommended in new and i keep putting on. really bulletproof