Are smaller turbocharged engines truly more efficient long-term, or do they wear out faster than larger naturally aspirated ones?

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H0SS_AGAINST@reddit

Think about it this way:

-Modern Turbo 4 cylinders make NA V8 power.

-Energy, and therefore power, is converted from pressure to rotational energy at the crank. All other parts (valve train, injectors, etc) experience no additional wear by making more power.

-V8s and I4s have the same number of crank and rod journals. V8s just have two rods per journal.

-Make the I4 rod and journal bigger, no issue.

The next thing to think about is the turbo. Over the years turbos have become more advanced and more reliable. They're also usually water cooled so you're not cooking the oil in the turbo leading to premature wear.

Does complexity impact reliability? Generally yes but it is well mitigated. Also, a failing turbo is usually not catastrophic. You have some warning, and replacing a turbo usually costs less than a whole new engine. The weight savings help economy and performance.

Most of the lifecycle engineering and reliability risks of modern vehicles is in all the gadgets and emission systems. Your backup camera, touch screen, or control modules are likely to fail before your engine and those will be installed on your modern vehicle regardless of your engine configuration.

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beipphine@reddit

The best turbo 4 cylinder in a car today makes less horsepower than some NA V8s did in the 1960's.

Ford FE 427ci - rated at 425, actual was closer to 600

Chevy L88 427ci -rated at 430, actual was 550

Chevy Zl1 427ci - rated at 430, actual was 585

Modern NA V8s are more powerful yet.

Chevy LT6 333 ci - 670 hp

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Dramatic-Season-2959@reddit

You’ve never heard of the overinflated SAE gross HP ratings, huh?

Manufacturers overstated their power numbers on purpose.

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H0SS_AGAINST@reddit

Did you really just list off performance V8s as a specific power density comparison to economy turbo 4 cylinders that produce peak torque by like 3000 RPM?

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jones1st@reddit

And he went the wrong direction on all the hp numbers to correct to real

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7ar5un@reddit

Seriously lol My old 84 corvette crossfire 5.7L 'merican v8 made (advertised) 205hp and 290tq.

My tlx 2.0L turbo makes (advertised) 272hp and 280tq

A 10tq difference is next to nothing and funny enough, in the acura that tq is from 1,600rpm where the tq in the corvette is from 2,800rpm.

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hatred-shapped@reddit

If you follow the instructions and maintenance schedule to the letter, they should be good in the long run. I've had aftermarket superchargers in Honda engines that lasted for over 200k and factory turbo VE engines (gas not diesel) last over 300k.

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UniquePotato@reddit

Many that have the longer 12000+ mile service intervals are way to far apart. Many have reliability issues after 100,000 miles

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fprintf@reddit

Anecdote and no data. Typical for Reddit. How about you show your sources?

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UniquePotato@reddit

Typical of a Redditor to doubt something that is well known.

Have a google on JLR’s Ingenium engine or BMW’s N47 & N57. All have known timing chain wear issues that lead to catastrophic failures which are attributed to oil degradation because of long service intervals. The JLR engine also suffers from oil dilution and other issues. Obviously not every engine is going to fail and there are many factors like weather and driving style that influence. But if you want the beat chance an engine will reach 200,000 miles more regular servicing is key.

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xGreenWorks@reddit

“I don’t have an anecdote as I’ve never had an engine problem.” You are using your personal experience as proof, which is anecdotal. Then you are providing more anecdotal evidence via the motors in the paragraph below.

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CardboardHeatshield@reddit

We're talking about engine reliability here man, not trying to find the neutrino. If you discard stories people tell about their engines failing then of course there is no evidence. Who is going to fund a study that shows the engines that the entire market is moving towards are more prone to failure, not less? In absence of that, who is going to study it on their own dime?

Of course there is nothing but anecdotal evidence here.

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xGreenWorks@reddit

There are literally millions of oil analysis to look at.

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UniquePotato@reddit

I’m being anecdotal to oppose the point I am making

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CommonBubba@reddit

When you can find more than three sources that say the same thing, it’s not anecdotal and you don’t need to quote the source…

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Carbonbuildup@reddit

The first Mini Cooper S had service intervals of 25k (oil change). After 6 months and 1000s of motors it was changed to 12k. Personally I’d be doing it at 6

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Munster19@reddit

Honestly why not just do it every 5k?

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what_to_do_what_to_@reddit

That seems a little high. Maybe aim for 4k.

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Upbeat_County9191@reddit

After every drive an oil change

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RickySlayer9@reddit

The German way

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Invisible7hunder@reddit

Just keep the drain plug half open and pour fresh oil in as you drive.

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Odd_nonposter@reddit

Why not keep a drum of oil in your passenger seat and plumb up a single-pass system?

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shadire@reddit

Perhaps 3k?

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xSpec13@reddit

Username checks out, as far as the 2nd gen S models go.

I had an N14 (probably the worst one?) for a number of years and always changed it between 5-6k miles, and it still looked like well used diesel oil by then.

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DollarStoreDollars@reddit

There’s no replacement for displacement?

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Accomplished-witchMD@reddit

I have replaced my TDI turbo 2x BUT after the 2nd I did the fix delete and she's been doing great and her mpg is higher.

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Carbonbuildup@reddit

Turbo = stress. The reason grandmas old caprice lasted so long is low hp and large displacement. Lethargy is reliability. Smaller complex turbo motors are designed to make marketable hp while meeting cafe standards. As someone who’s worked for both GM and Chrysler at the corporate level I can confidently say that once the warranty is up, they don’t give a fuck.

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AdaptationCreation@reddit

Engines that come from the factory with a turbocharger were designed to handle the extra stress, so that's not added stress.

There's nothing complex about a turbocharger once you know how they work.

Some of the most reliable engines out there used a turbocharger. Like the VW diesel in the Jetta and Golf. My TDI was over 300k miles when I sold it and it still ran like a champ.

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The_Coalition@reddit

The difference between turbo diesels and turbo petrol engines is so big that there is no point comparing or extrapolating from that. A turbo diesel is completely fine unless the boost pressure bends rods or something like that. There's a good reason why almost nobody made a naturally aspirated diesels in the last 20 or so years. Meanwhile, a turbo petrol engine must maintain a delicate balance of boost pressure, throttle opening, ignition timing and god knows what else in order to simply not explode. Also, turbo diesel engines tend to produce about as much, or only a bit more power than naturally aspirated petrol engines of the same displacement.

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DonEscapedTexas@reddit

right

whereas a recent 5.3 Chevy risks lifter failure because regulation drove retrofitting of marginal systems for modest return

I'm watching the Dodge straight six hopefully

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ThePoltageist@reddit

Modern turbos and are a lot more reliable than they were fifteen or twenty years ago and the aluminum block may not be as durable but under normal stress it was designed for its fine, reliability isn’t the issue, they don’t build these cars to ignore maintenance anymore tho, because your grandmas caprice was always under stressed it could shrug off neglected maintenance more easily and even if it went too long for even that, the iron block didn’t warp out of spec and much less often cracked, these new engines will warp, will crack, if you ignore maintenance. There is no rebuilding these aluminum engines, there is only replacement.

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Carbonbuildup@reddit

What are you talking about? Aluminum blocks have steel sleeves, that are easily replaced, cam bearings are press in steel/nickel, main bearings can be easily replaced. Every gm v8 since 2015 (gen V LT series) is an aluminum blocks).

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ThePoltageist@reddit

Yeah do that broski, the head can’t be resurfaced, and it doesn’t matter how many sleeves you toss in if the block is warped out of tolerance and again refer to the cracked engine block, you gunna sleeve that one? Obviously I’m referring to a situation where something like a blown head gasket due to overheating happened. And tell all those machine shop bros that closed down because of this it’s ok they were wrong go open the shop back up?

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Carbonbuildup@reddit

“Can’t resurface aluminum”. I’ll let the machinist world know that head deck plates are total BS. Broski.

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ThePoltageist@reddit

So then tell me if all this is so possible like you think why does literally no modern engine get rebuilt? Because thy don’t… it’s not economically viable to rebuild a newer engine for less than buying a brand new one, literally for the reasons I mentioned?

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Carbonbuildup@reddit

I’m not into internet arguments, just read man.

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ThePoltageist@reddit

Ah yes required to pony up something realistic and you are done. Because I have read and well they think you are wrong. And reality reflects that because engine rebuilds are not a thing on new engines.

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Carbonbuildup@reddit

You will just argue. I could tell you I’ve raced 911s and vettes for 30 years and you’ll argue, It doesn’t matter to me. You’re right, I’m wrong and I apologize, can I go now?

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ThePoltageist@reddit

You know what I’ll let you off the hook, because I respect what you have done. we could get into semantics about how rebuilding a fucking race car is different and probably explains why you are out of touch with what the reality is for the rest of the automotive world. But again I respect that you probably drive really well if you aren’t just bullshitting so take care and have a good day.

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Sea-Requirement4947@reddit

As someone who’s also worked at GM, STLA, and Motorsports…I’ve been preaching this over-stressed engine bit for a while. No way I’m buying a 2.7L turbomax Silverado. I think we designed them to last the lifetime of a lease. Meanwhile my cousin has older 5.3 LS motors running around in his lawn care and plow fleet with well over 300k on them.

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lurkinglen@reddit

So strange the difference in perception of car related topics between US and Europe.

In my country those numbers would've been 1.0 for the small engine and 2.2 maybe 2.5 l for the large engine. And the abbreviation of liter is a non-capitalized l.

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Intelligent_Part101@reddit

Since you decided to nitpick, please stand corrected: the SI standard states EITHER a lowercase or uppercase L is valid for the liter unit. The American National Institute of Standards and Technology strongly prefers capital L because lowercase L is too easily mistaken for the numeral 1. Capital L is unambiguous.

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Reallybarb@reddit

In your country you're generally not hauling as heavy, going as fast, or having the same safety standards which weigh down cars.

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Unique_Watch4072@reddit

It stems from the fact that in Europe we traditionally have much denser towns/cities and not so much rural use apart from farmers, at least on the mainland, in Iceland we're a bit of mix of both and for me anything under 3l is small, but it's also relative to whether I think of suv/truck or a regular passanger car.

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Disastrous-Group3390@reddit

I’m used to 5.7 being ‘small’ and ‘large’ starting at 6.6-ish. I love that Cadillac chose to put badges on the early ‘70s Eldorado that said ‘8.2 LITRE.’ Wnd over at Dodge, they put a 2.4 litre supercharger on top if the 6.2 litre engine.

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oneaccountaday@reddit

This violates the NDA you signed.

Yes we know about the oil pressure sensor issue and the constant R2D banging slow shift issue behind the 5.3 and 6.0 but they’re still hanging together even with the exhaust hanging off.

Jokes aside these things are like old farm tractors. You put some half water half fuel in them, a little oil and some ATF and a quick jumpstart and they fire right up.

2 quarts low on oil, it’s fine, “low coolant” just a sensor, electrical issue, clear the code. These old rust boxes are tanks.

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Sea-Requirement4947@reddit

Ha! Yeah around here the truck will rust out before the 5.3 gives. The ole’ 4L-slippy will wake up one day and decide that all forward gears are now Neutral, but that’s a pretty straightforward rebuild for the money.

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johnb300m@reddit

That’s your management’s fault. Not the engine or turbo technology.

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Carbonbuildup@reddit

The LS hasn’t eaten it’s cam and lifters? They’re great motors and I have a LS Corvair, but lifters and cams are the norm, even the mighty LS7 would grenade the valve train - pulled rocker studs, bent pushrods. Etc

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Cobrachimkin@reddit

People knock on the 4Runner for being slow, but that’s why they last forever. A modern 4.0 V6 making 278 hp has very little stress being put on it.

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redditisahive2023@reddit

They had a lot of head gasket failures in the mid 2000’s. It was their 1st high output v6.

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geardownson@reddit

Of the newer 4 runners which ones to avoid? I've been thinking of getting one for a while. I'm looking around the 20k ish range on price so that puts me in the teens.

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Reallybarb@reddit

You can get any 5th gen 4runner and be perfectly good.
The ones with head gasket issues were the early 4th gen

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Cobrachimkin@reddit

I was thinking more of the 5th gen 4R, the second gen 1GR has an expected life of 300k miles with not a lot more than oil changes.

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Trevor775@reddit

Arnt the newer 4 runners turbo too?

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CarsandTunes@reddit

I have never understood how people can complain about an SUV being slow. It's a bloody suv! It's not supposed to be fast. And it's still fast enough to keep up the traffic, and still fast enough to get you a ticket.

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Environmental-Toe686@reddit

I just sucked some mouse chewed air filter media and good knows what else through the intake of my 3.4. It died on the side of the road and all I did was clean out the air box, start it up and floor it until it started revving again. A few backfires along the way but it's running like a sewing machine again. 289k miles. I would drive it 8 hours today and I started it for the first time in months yesterday.

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oneaccountaday@reddit

My 84 4banger auto could barely do a burnout on ice. Going 70 was a “miracle on ice” the thing should’ve been in the movie.

Worn out leather belt pieces for rod bearings, with a top end rebuilt by someone using sticks and stones and the thing still ran.

A V8 4Runner is on my short list, a 7 injector supercharged would be a close second.

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Pale-Ad6216@reddit

Also consider a Lexus GX 470. That’s my daily driver and it’s got the same V8 engine, just a bit nicer inside and it’ll have the 3rd row seats if you want/need that.

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oneaccountaday@reddit

I love the 470s, great vehicle. I’d probably end up going Land Cruiser with the diff locks though.

I just like the “special edition” ones, but not too special like AMG, R type, GTI, Platinum, Rubicon, GMT800s with a Duramax and sunroof, SS, grand sport, z06, SRT, etc.

I just love the size of the underpowered v6 4Runner a slightly less underpowered 4.7 makes it more fun.

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Pale-Ad6216@reddit

My son found an 09 2wd 4 runner with the v6. It’s in pristine condition. Got it from a Toyota dealer with 132k miles for less than $9500. It’s so clean. I’d drive that till the wheels fell off. He’s not crazy about the gas mileage. But oh well. It’s better than my GX.

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ofm1@reddit

My 0.6l engine Suzuki with 42hp should last till doomsday.

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CadetObvious@reddit

In my opinion, the 1GR-FE belongs in the same legendary reliability tier as the 300 I6. More often than not, the rest of the vehicle succumbs to age and corrosion long before the drivetrain ever shows signs of giving up.

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evildaddy911@reddit

The 5.7L, I think 3UR, in the Tundras was super reliable. We had one for a farm truck towing equipment to/from the fields, pretty much always overweight, until the bed was too far gone we couldn't use it. Just oil changes every 8-10k and brakes every 75k for about 15 years

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Dexford211@reddit

My 1 liter 60hp engine should last forever then.

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t-w-i-a@reddit

So what you’re telling me is I shouldn’t have bought the Ram with the hurricane lol (straight six turbo)

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Carbonbuildup@reddit

Just be on top of maintenance, change oil religiously, etc. we’re so used to a world of disposable appliances that we’ve ended up treating cars the same.

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nlevine1988@reddit

It didn't hurt that grandmas drive, well like grandmas.

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johnb300m@reddit

Cool story bro. GM and “the blob formerly known as Chrysler” don’t give a FUK about their naturally aspirated engines either.

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Skirra08@reddit

That's true but they've also never given a fuck after the warranty is up. And in the meantime design, metallurgy, and manufacturing have improved. You remember Grandma's old Caprice last g so long because of survivorship bias. I remember when 100,000 miles was considered a lot of miles on a car. And when you actually had to worry about your car starting every morning. That really hasn't been the case for most cars over the last 20 years. Sure every car company has dud engines or transmissions but they did back then too. Fieros lit themselves on fire, pintos exploded, and all of them got crappy gas mileage. Not to mention the occupants were the crumple zone.

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rdmodsrtrsh@reddit

Half the time it seems like they don’t give a fuck under warranty….. ie me trying to get the corrosion taken care of while under warranty on my jeep

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dinosaurkiller@reddit

Sorry, you should have read the fine print, car repairs aren’t covered under this warranty

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Dredgeon@reddit

They just now managed to get an acceptable rating on rollover risk for the Wrangler. And all it took was a single chassis beam change. Cheap bastards.

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Commies-Fan@reddit

Grandmas Caprice lasted forever just like grandmas turbo 4 will last forever. Grandma will never even get into the turbo. My MiL barely touched the gas on her Cadillac ATS the only time the turbo spooled up was when I drove it. Same with her ‘99 Deville.

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south-of-the-river@reddit

There are exceptions to the rule.

Those exceptions are often Japanese and run on diesel. I’ve seen turbo diesel hiluxes rust away before the engine packs it in

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GrenadeJuggler@reddit

Was gonna say this. You have to actually set out with the intention of blowing up a Hilux, and even then it is probably going to eat whatever you throw at it.

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SovietPatrickStar@reddit

Had an answer from corporate regarding a ticket on a transmission rebuild.

As authorized warranty replacement there was a repair set or a new transmission. Problem was that the repair set was lacking parts so the repair itself was only a delay of faileure instead of preventive.

New transmissions were out of stock.

Anyways the answer was basically: we don’t care if it fails again, as long as it doesn’t fail during warranty.

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RevolutionaryBeat301@reddit

As someone who has owned a car with a turbocharged 4 cylinder, this is 100% correct. It was the only car that I ever owned where the engine self destructed. It actually did it twice. The first time, I replaced the short block. After I sold the car, the guy I sold it to spun a bearing after about two weeks.

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Sea-Requirement4947@reddit

A fellow Subaru EJ connoisseur???

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RevolutionaryBeat301@reddit

Lol how’d you guess?

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Dredgeon@reddit

both GM and Chrysler

I think I found the problem. Plenty of great four cylinders coming from manufacturers with engineering departments that are bigger than their legal teams.

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uwpxwpal@reddit

Grandma's Caprice lasted so long because she only drove it to doctor's office, grocery store, and church.

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Sad-Warthog-4996@reddit

I have to disagree. Constant short journeys will cause problems. The liquids never reach their operating temperature. Like dogs, vehicles need a good stretch of the legs regularly to stay healthy and happy.

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KnoxVegas41@reddit

Yep. Oldsmobile 307 engines will run forever. Low compression, cast iron, slow revs.

Not much power but dear Lord are they bulletproof.

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vargemp@reddit

Check what mileages the 1.0 TSI does before anything goes wrong.

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Some_How_I_Manage@reddit

I will add BUILT engines to that metric, specifically ones that restrain HP to less than used areas like high in the rev band. You have high revving, high HP/displacement 4 cylinders that last for multiple trips around the moon.

The issue is being engineered for stress, and every single small displacement turbo engine are very cheaply made using very cheap materials.

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oneaccountaday@reddit

The honesty is real with this one. ☝️

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KostyaFedot@reddit

Turbo can't last really long. Usually just for extended warranty, which is under 200.000 km.

Typical operating speeds are 80,000–200,000 RPM for turbine.

While engine with large displacement will be at 5000 RPM maximum.

Higher RMP is, less it lasts.

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glasswings363@reddit

I'm not convinced. PT6A turboprops go 3,000 \~ 3,600 hours between overhauls, a Lycoming O-320 (naturally aspirated 320 cubic inch boxer that shouldn't rev faster than about 3000 RPM) is maybe 2,000 hours.

In car terms that's like 90k miles vs 135k.

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KostyaFedot@reddit

So, it lasts only 90k miles. Means junk.

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Nodnardsemaj@reddit

From my understanding they stress the engine and commonly go out before 80k miles. They're cool but impractical 😔

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Agile_Session_3660@reddit

Depends on the part and build quality. Anyone saying this is an easy answer doesn’t know what they’re talking about, and you’d need to provide specific examples. For instance the Audi inline 5 is hilariously overbuilt for the factory 400hp output and would outlast most other factory 400 hp engines on the market if kept at factory output.

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jrodicus100@reddit

Failure rates seem to support this, with Hundai/Kia having the highest engine failure rates followed by Chrysler, GM, Ford.

GM had huge issues with their NA V8, Toyota had issues with their V6 Turbo, and Kia has issues with… all of them?

It’s not the engine type, it’s how it’s designed and built.

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jnyc777@reddit

Agreed it’s not exactly a one size fits all, but op did say smaller turbo charged engine, I’m assuming is related to 1.4-1.5lt in most new cars

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Agile_Session_3660@reddit

Maybe, but you could compare for instance the Audi inline 5 to an equivalent 400hp larger engine, and the Audi inline 5 will basically outlast everything if kept stock due to how insanely overbuilt it is from the factory.

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jnyc777@reddit

Did the inline 5 have steel/iron cylinder liners? Another issue with most modern engines are thin either welded or cast into the aluminum sleeves. High combustion chamber pressures from a small displacement engine trying to make torque

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Agile_Session_3660@reddit

No, it’s that plasma lining process done on the aluminum block itself. Really good article that Audi produced that shows how overbuilt the engine is for 400hp. https://static.nhtsa.gov/odi/tsbs/2017/MC-10127901-9999.pdf

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jnyc777@reddit

I’ve personally had bad luck with “Lokasil” liners. So I’m biased on that part, the plasma/welded liners may be far superior🤷‍♂️ I know the inline 5 as well as the vr6, metzler and even 1.8t are/were great engines from VAG. There 1.4lt though???

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Tangboy50000@reddit

Modern turbos are designed to last longer, but most will fail between 100,000-150,000 miles. You have to be diligent about changing oil because of the way turbos operate. Most people don’t know about cooling cycles, where you idle briefly before shutting the car off to prevent “oil cooking”, where trapped heat in the turbo breaks down the oil left inside.

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K_Linkmaster@reddit

Don't some makers have an idle that runs until cool down is achieved? Meaning after you shut off the key and walk away, it does its thing and then shuts off. Coulda sworn it was a subie thing, but I've been wrong before.

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gropingforelmo@reddit

Not sure if any factory turbo engines come with turbo timers stock, but the ones I have experience with recently didn't need it because the turbos were plumbed into the coolant loop. Even without coolant circulating, there's enough thermal capacity there to handle most any normal situation, even for more performance oriented vehicles.

There have also been significant strides in improving engine oils, so drain down isn't as much of an issue. Every factory turbo car I've owned specified full synthetic, which probably contributes.

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OTPguy@reddit

I'm surprised that modern turbo vehicles don't come with an electric oil pump. Imagine being able to prime the 'internals' with oil before starting, and then having some sort of temperature controlled cool down timer.

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K_Linkmaster@reddit

Cool idea. Do you know if any makers had an automatic shutoff or am I imagining that?

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OTPguy@reddit

No clue, but since the 1990s it was very easy to replace your mechanically driven oil pump with an electric one for the 1960-1970 era big engine muscle cars.

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FaithlessnessEasy276@reddit

You mean fuel pump I think

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OTPguy@reddit

Nope. I mean oil pump.

One quick example here, and maybe the market has changed since the 1990s:
https://www.summitracing.com/parts/ear-op111erl

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woolash@reddit

My 2016 GTI had an electric pump that kicked in when motor was shut down to cool the turbo. I thought it was common?

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OTPguy@reddit

I don't think it's that common on modern day passenger vehicles. I know some of the big diesel Ford trucks have them, but I'm pretty sure most 'little gas' turbo engines don't have them. My turbo vehicles don't.

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FishFingerAnCustard@reddit

Turbo timer.

No idea if anything comes with them factory, but it’s a pretty common mod.

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DFLDrew@reddit

What are you talking about failing at 100-150k? Please show any evidence that this is widespread

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AdaptationCreation@reddit

Modern turbos are oil AND water cooled so oil "coking" doesn't happen. Oil cooking is something you do in your kitchen. Oil coking is something that happens inside a turbocharger when it gets to a certain heat range. It forms solid deposits when it hits a certain heat range.

Turbo timers aren't needed anymore because the water cooled part of the turbo continues to circulate after the vehicle has been turned off.

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Ok-Highlight-3402@reddit

Yes.

But car makers build them like cheaply, and customers maintain them even more cheaply.

That said I feel like mid-90s-2008 was peak reliability.

But a turbo car can go 1,000,000+mi just like an N/A.

Modern transport trucks are more highly stressed than they were in the past and last even longer than they did back in the day.

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No-Reason-2822@reddit

The biggest variable is maintenance. If the car makers could actually get around the regulatory reasons why official maintenance schedules suck, and offer official, professionally executed, maintenance plans that are actually designed around the lowest cost of ownership (aka: maximum usable life of the vehicle), they could sell high-cost, high-margin vehicles that last forever.

Instead we have this broken, race-to-the-bottom model where it’s every man for himself as soon as the vehicle is sold new. The only winners are the ones who understand vehicle systems and technology, and have the discipline to gather the data and execute the maintenance themselves because, trust issues. It’s like some f’d up game of monopoly where every time the dice don’t roll perfectly in your favor, you end up paying the OEM, the dealer/repair shop, and the bloody bank.

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Rexaroooo@reddit

If you look at the type of person that buys a newer crossover with a small turbocharged 4 cyl, who drives it from A to B normally and takes care of it, that engine will be just as reliable as a similar N/A engine imho

But if you look at all the professional race car drivers getting 2.0T VW GTIs, tuning them, and ripping them down the highway like assholes, that’s a different story

And no I don’t want to hear about your VW and how reliable it is.

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Bubbly-Pirate-3311@reddit

Would you like to hear about how reliable my Audi is?

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Rexaroooo@reddit

Trick question, there’s no such thing

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Bubbly-Pirate-3311@reddit

Lalalala I can't hear you

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moonlite_equilibrium@reddit

Would you like to hear how unreliable my vw is 😏

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johnb300m@reddit

This is bs. VW just chose to use a shitty, cheaper turbo then.

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Rexaroooo@reddit

You don’t have to, I have my own shitter GTI in the driveway that I can’t wait to get rid of

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oneaccountaday@reddit

Yes, and the $500 dome light sensors in the doors!

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StarsandMaple@reddit

Eh it's all about the same now.

190K mile B58 with hybrid turbo, tune, etc... making close to 500whp for over 120k miles no issues.

Technically yes a larger N/A motor with a moderate to low compression (8.5-9.5) will outlast on average a turbo engine but itll really come down to the engineering and maintenance.

GM 1.4t sucked, but like a B58 BMW motor is stout as can be, and B48 is similar.

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lpg975@reddit

And then I got 300k miles out of my 1.4 turbo LUV with just oil changes every 10k miles and bulletproofing by replacing the PCV system and swapping plastic parts for metal. Must have been a miracle, I guess. And I was FBO and tuned for 250k miles of that lifespan. And it still ran when I sold it lol.

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StarsandMaple@reddit

Yeah. Turbo engines aren't inherently worse, it all comes down to design, engineering, and maintenance. If turbo engines were so unreliable semi tractors wouldn't be i6 turbo getting 1.5million miles. I mean look at an OM606 Mercedes diesel .. there's probably hundreds with millions of miles, I know of two personally

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lpg975@reddit

I mean, diesels are built a bit different, but I get what you're saying. Still turbo'd, and generally much higher psi than a gas turbo engine too.

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Transmorgrafier_2024@reddit

Small vs Large engine displacement and reliability.
All depends on the engineers and the company ethos.
We see Suzuki Hyabusa 1300 I4 motorcycle engine in cars and motorcycles at Boneville producing a very reliable 600 hp with the turbo.
This engine is a legend. Most Suzuki engines (and they make a huge variation worldwide) have a stellar reliability record.
For sure, GM and Chrysler engineers have build good engines in large numbers. But unsure if the company engineers and management take them to “Kanpiki “. Suzuki made that step decades ago. ( I own a DR650 and a DR350 and can vouch for the unbelievable reliability of there engine under very difficult conditions) .02c worth.

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N_ModeVN@reddit

Put good oil in them, follow the book with the recommended viscosity, change it every 5K you’ll be fine.

That said, in my ND3 it calls for 0w-20.

I use 0w-30 every 5K since the motor turns a lot of high RPM.

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Dan_E26@reddit

"Turbos are CoMpLiCaTeD!" and "SmAlL MoDuR bAd!" are two of the laziest takes I see CONSTANTLY in the car world

Automakers have been building turbo engines for decades. This isn't new technology. Yes, they tend to require that the owner is a bit more proactive on their maintenance (which, in fairness, most people are not) but there are plenty of perfectly reliable modern turbo engine platforms. VW EA888, Honda K20C, B58, Ford 2.3/2.7/3.5 Ecoboost

Also, OP: your question is sorta apples and oranges. Efficiency ≠ long term reliability.

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johnb300m@reddit

What’s shocking to me is I see claims like this all the time from people who claim they work for GM, Chrysler, whatever. That’s scary then. I’d that’s how their staff believe, the I’m fine with American autos going completely out of business.

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danielling1981@reddit

This is reddit.

How dare you stop me from claiming w/s I want to be.

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ChemistRemote7182@reddit

Keep in mind that all that extra plumbing for moving air coolant and water and the turbo itself, these are all things that age and wear

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Substantial_Team6751@reddit

Efficient and wearing out are two different things. I don't think car companies really care whether the engine lasts 300k miles.

The biggest problem with turbos is heat.

A Honda CRV used to be at the top of my list (legendary normally aspriated 4 banger) but now it's a 1.5L turbo. Nope, not going to do that. The hybrid though has the NA engine so that maybe be on our list.

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Striking_Luck5201@reddit

It all depends. Compared to what, to do what, and with what fuel?

A turbo on a diesel engine is a very different experience to a turbo on a gas powered car.

Nothing is stopping someone from designing an engine that relies on a turbo charger to make the system more reliable. It's just that no one ever does since the market is addicted to chasing hp numbers.

In the world of gensets and industrial engines, its done all the time.

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ottrocity@reddit

141k on my tracked, autocrossed, tuned small turbocharged engine shoving 27psi into itself.

Have anecdotal stories of many NA engines dying long before this doing similar things (or even less, L87, Ford 3.8, 2.4L Ecotec).

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Real-Mode-3417@reddit

Ford Ecoboost engine is very reliable. One of the better engines out there

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firm_hand-shakes@reddit

Most turbo cars need higher octane fuel also. Something to remember.

See a lot of complaints about gas prices (yes they’re high) but people don’t do the research to know that their potential new car uses higher octane.

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rwebell@reddit

Higher RPM, higher compression, more heat, lighter materials, more emissions control, more electronics, more complexity….none of these things are saying reliability to me. We are getting some better materials alloys and synthetic oils but running a smaller motor at higher RPM seems like a recipe for failure.

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rival_22@reddit

Related question, when they go, do turbos just fail, or do they lose efficiency/power?

Like at 150,000 miles, will one just run not as well, or is it all or nothing?

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largos7289@reddit

The answer is depends... I had a srt-4 that i upgraded the turbo to a 50 trim and bumped it from 10lbs to 20. It was able to take it because it had forged internals. You get that cast crap in there and they only put the boost up to 8lbs then your OK. I liked the turbo 4's they are really fun but i wouldn't want to own one again. I'm not turbo friendly.

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lpg975@reddit

Keep up on the maintenance and they'll last quite a long time. But I'll get downvoted because this doesn't fit the narrative of doom and gloom and new engines =bad!

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BothEntertainment00@reddit

They require maintenance done on time, but can absolutely be reliable for a long time. Most common people suck at maintenance and they can't neglect it like their old Toyota.

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Pale-Ad6216@reddit

My son has an 09 v6 4 runner.

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AgitatedHat5620@reddit

Yes and no. They are more efficient long term but they wear out faster. High compression in the cylinders puts more stress in everything. Turbo is a brand new failure part and have their own oiling and cooling systems that now have to be maintained. Turbos get very very very hot and can cause damage to surrounding components over time.

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Stunning_Two_1599@reddit

Lots of engines are having problems these days including the GM L87 6.2L. No turbo on those.

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Recent-Lemon-9930@reddit

It's a gradient.

Simple, reliable, proven, 40+ year old designs made properly and with a little turbo attached, fine. Especially on a petrol they can be surprisingly simple and cheap to replace.

In a new-ish designed 1.x litre engine in a 2-ton car trying to get 250+ bhp? Yeah, something's going to go quite early, and when it's replaced you'll fine out the newer weak spot soon enough.

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RicardoNurein@reddit

I asked my maintenance guy. He gave me the same side eye when I joked about blinker fluid and said I should early adopt driverless for my EV

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steak5@reddit

Wrong question to ask.

Reliability of an engine depends entirely on who made it and the quality control of the engine maker.

A Turbo k20 engine from Honda is going to be more reliable than a NA engine from Land Rover.

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rnewscates73@reddit

There is massive recall underway now ‘25 - ‘26 of turbo engines in Nissan/Infinity, Toyota/Lexus, and Jeep.

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Hersbird@reddit

Even if they last as long, they don't, but even if they did you have a whole separate, expensive system that will also be a point of failure. The turbos on a new Tundra are over $8,000 by themselves. On top of the more expensive longbock they sit on which are failing at a rate 100 times higher than the 5.7 it replaced.

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pwnageface@reddit

Hard to say. Depends how hard you drive it. Ive known people to take a turbocharged engine and get 200k miles before turbo needed a rebuild or engine needed gaskets etc. I think as time has gone on they've gotten much more efficient, but someone's definition of vehicle longevity varies greatly from person to person. I buy a car and expect 250k miles out of it. Most people are getting a new car every 5ish years. My current car is a 2016 and sitting at 50k miles. If I keep at this rate ill have the car another 25 years lol.

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GrenadeJuggler@reddit

Short answer? No.

Long answer? Also no.

More parts means more shit to break. More shit to break means lower reliability and lower long-term efficiency in the name of almost pitiful fuel mileage gains.

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s_nz@reddit

They are much more efficient if you stay off the boost (keep RPM under 3000 or so). This means they do quite well in economy tests.

But typically people drive more aggressively than the test cycle, and they are really thirsty when on boost.

They are more complex, and do wear out faster too.

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DFLDrew@reddit

A turbo 4 cyl is not more complicated than a NA V6. Honestly, turbos add a negligible amount of mechanical complexity

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OTPguy@reddit

You can have "eco" or "boost" but not both at the same time. ;-)

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D3athAdd3rz@reddit

My Fiesta ST has an Ecoboost engine that's currently averaging 20.4mpg... maybe I should lay off the boost half.

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buttsnuggles@reddit

Which is actually the beauty of turbos. You can get both eco and power based on your needs.

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OTPguy@reddit

Yup. That's why I own then, until I replace all my fossil fuel vehicles with EVs, which will be soon-ish.

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Professional_Bat9174@reddit

Exactly. As much as I love a turbo 4 or 5 cylinder, they are actually potential gas hogs.

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Cyndagon@reddit

My Golf R guzzles fuel 😅

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s_nz@reddit

Depend a lot on the driving style. If you are a gentle driver (who wants the ability to get out of a situation quickly if the need ever arises), then a turbo setup is a good pick.

But if you like hearing the engine roar, you are best not to.

Recall using almost an entire tank of petrol on a turbocharged subaru legacy station wagon, towing a 1500kg boat (racing yacht, so lots of stuff in the wind), just 228km. Could hear the turbo sucking air in for the whole trip.

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I_Have_Unobtainium@reddit

Ya my volvo wagon was getting 20mpg regularly. Inline 5 was thirsty.

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Informal_Draft_2347@reddit

I have one right now and I am not impressed. The projected 1-3 mpg city driving savings in my opinion is not worth it and the 4-6 on Hwy just isn’t enough for whining sound. We will keep it as a commuter car until it has significant issues. My wife wanted it because of the red interior and the seats were comfortable for her so I do not regret it but I do miss the V6.

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No_South_9912@reddit

Most engines from the 1980s needed major service/rebuild before 100k..

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OnlyCommentWhenTipsy@reddit

I would argue smaller turbo charged engines are less tolerant to abuse and poor maintenance. When maintained and used at optimal rpm there's no reason a (modern) small turbo charged engine is going to wear out faster than a larger NA.

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Nearby_Knowledge8014@reddit

“No replacement for displacement”

There is a reason that old American v8s just keep chugging along, in otherwise unspectacular vehicles.

It’s a proven winning formula. It’s being thrown out the window for smaller engines and turbos and hybrids just to make cars more expensive to repair.

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Ok-Office1370@reddit

Reddit car guys repeat myths from the 1900s as "fact".

Turbo cars existed prior to World War I and the only reason they went out of fashion was war shortages. Today's turbo engines can easily be just as if not more reliable than their counterparts.

Reddit keeps repeating "less parts more reliable". This is dumb. For example, the reason cars today have "more problems" are things like the OBD sensors catching problems before they become terminal. Old cars just ended up in junkyards because you didn't even know you had a problem until it failed.

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DueCartographer4915@reddit

Had well over 150 plus on my eclipse before I refreshed it. Looked great when it was apart but I also do maintenance on time

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MichaDaFox@reddit

As a general rule I would say based on my "help friends fix their cars" shade tree mechanic work, that all things being equal (ie Vehicle weighs about the same, Similar specific power output ) the larger non turbo engine is going to last longer or handle neglect better. There just tends to be more stress, more extreme heat cycling, larger cylinder pressures and temps that increase wear with turbos.

If you stay out of boost, then yes it may return better fuel economy during low demand use ( like highway cruising). As a general rule though, I have found that a turbo engine in the real world will roughly consume the same fuel as the next engine (2 Cylinders) bigger. So say a 2.0 Turbo 4, will post about the same peak HP and have similar fuel consumption to a 3.0 v6. A 3L Turbo V6 will post the same peak power as a 4.0 V8 and so on which tends to be the normal manufacture stratification or was for decades.

Anecdotally though this has variability based on the platform and specific design. My car is 30 years old and still on its original ceramic nitride ball bearing supported turbo, and the V6 Turbo is generally regarded as being more reliable and cheaper to maintain than the V8. The V6 Turbo was actually faster due to an earlier torque peak and more area under the torque curve, and got slightly better fuel economy. The V8 selling point was "a v8" and "smoothness" combined with longer oil and service intervals.

In my opinion : If you change the oil regularly (I do 10k KM or 6 months), Make sure you stop fluid leaks of all kinds as soon as you find them. Drive gently while the car comes up to operating temperature, and idle the car for 2 minutes or so after driving it to circulate oil/water and cool the turbo back down before turning the car off and it should last longer than you would want to keep the same car.

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Bulky-Travel-2500@reddit

New Turbocharged small displacement motors wear out faster than any NA motor. Plain and simple. They have ultra tight tolerances, run hotter, demand meticulous maintenance that average people do not perform and are much more complex.

Manufacturers are adhered to CAFE standards, as such they cram boosted 3 & 4 cylinder small displacement engines into vehicles like pickup trucks & SUVs.

A few examples: a Jeep wrangler I was given as a rental. A 5000lb 4 door jeep with a 2.0L 4 cylinder that guzzled gas @ 16mpg highway/8mpg street and sounded like it hated life when accelerating (even nicely). Another is the ford bronco sport. They come with either a boosted 3 cylinder 1.5l or a 4cyl 2.0l engine and weigh almost 4,000lbs. One last example is my wife’s former vehicle, a 4800lb Buick cascada that looked fast but came with an overworked & anemic 1.6l turbocharged pile of shit that you had to push to get it to move with traffic. These size motors would do wonders in an escort, Corolla, geo storm or a civic of the 90s variety (lighter); not what they’re being used for now.

Plainly… They’re overworked, underpowered for the vehicle application & cost an assload of money to maintain & replace when they do break down. Which will happen.

This is why they made cash for clunkers. To get you out of that reliable Buick century with a 3.8L just to buy a new “efficient” Tacoma sized vehicle with a Toyota Yaris sized motor with ZERO improvements in MPG & guaranteed turbo replacement profit.

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SuspiciousGarlic4798@reddit

They can be more efficient. But theyre usually stressed more than an NA engine. Because theyre usually trying to get everything (fuel economy, power, emissions) Theres also more things to go wrong.

Also. Oil changes need to be done on time. If you miss one for too long bye bye turbo.

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kingForOneDay@reddit

Both can be true

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MotelSans17@reddit

I refuse to play the "small turbo engine" game, so I ended up with an EV.

I totally believe this is why Toyota went all hybrid for the RAV4, so they can offer great fuel economy without Uber complicated drivetrains (Synergy Drive hybrid powertrain are surprisingly simple, the "transmission" is just the EV motors joined with planetary gears, there are no belts and no shifts).

Unfortunately getting a new RAV4 would have been more expensive than a bZ.

CX-5 was another option, but hate the new "touchscreen only" interior. And fuel economy is not great.

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YogurtclosetDull2380@reddit

I'm fairly certain a blew the motor on a brand new Grand Cherokee the other day while passing on the highway. That thing stunk bad once I got it back to the dealership.

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topbeancounter@reddit

I always opted for the largest engine option if given a choice. I’ve owned a couple turbos. Never blew either up, but not for a lack of trying!

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tnsipla@reddit

NA will last longer than a turbo anyday everyday, especially between an NA 3.6l and a turbo 2.4l, you’ve shifted to a turbocharged smaller engine to get a similar ballpark in power and output at the expense of long term reliability and turbo lag

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WeakConfection1360@reddit

Smaller turbo engines are garbage

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SpaceCat72@reddit

Little turbo engines live short and hard lives. Big old engines that loaf along last forever. This mini turbo engine stuff was done in the 80s too. Almost none of them are still around.

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eXo0us@reddit

Volvo had been building decades of small turbo engine and they had been nothing but reliable.

But their main bearings, bottoms are also really beefy, which you can't say for some other brands i4.

So it depends how you design your engine. There is more stress per surface on a turbo engine so need to increase the surface. Not that hard to understand

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adultdaycare81@reddit

They test better lol. But real world doesn’t seem as good. Hybrid does seem to work well.

At least from the people who on balance make good automobiles. If a car manufacturer can’t figure out electronics at baseline, don’t buy their hybrid.

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scrappybasket@reddit

Efficiency and longevity are not the same

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PckMan@reddit

They are more efficient. Wear and tear is a complicated issue because it's actually rarely the turbo itself that develops issues, but rather other things in the turbo system. For example stuck boost solenoids, leaking boost pipes or intercooler or a stuck wastegate are the more usual causes for turbo failure rather than the turbo itself. Turbos are just more susceptible to damage from ignored maintenance, but as long as you keep up with regular maintenance schedules they're generally very reliable. The only thing that requires extra attention is changing the oil at the appropriate intervals, sooner than the manufacturer recommends, and using high quality oil.

The rest is stuff that affects other engines as well. Turbo engines are direct injection and this causes carbon build up at the valves worse than intake injection engines. Many natrually aspirated engines also have direct injection, in fact most nowadays, but turbo engines always have direct injection nowadays as well. Turbo engines are also under more stress and to reduce costs they're cutting it closer to design limits than NA engines. This doesn't mean they're inherently unreliable, it's just, as I said, that they don't take as kindly to neglect. You should never neglect your car's maintenance anyways but some cars fare better than others in neglect.

Long term the larger, less stressed engine, has the upper hand, but that doesn't mean that a small turbo engine can't be completely fine for 15-20 years.

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Hanoverfist101@reddit

There’s no replacement for displacement.

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dcsenge@reddit

People get rid of cars say they blew up. When they say a car blows up its just an expensive part that can be replaced, think Head gasket, transmission or Turbo, All are 1K+ servces. A turbo Car will likely need a head gasket and turbo replaced at some point in its life. They are servicable parts that are costly.

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huh_say_what_now_@reddit

Whatever sized engine if it's turbo or not is build to the standard to produce it's given HP, it's such a broad statement you're making it doesn't take into account if you talkin about a Rolls Royce engine or a Hyundai engine there are too many variables

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Nervous_Olive_5754@reddit

Yes. You have described the tradeoff. The best manufacturers are choosing a middle ground. Either they're not cranking the boost that high or we're going to higher compression NA.

They're also playing games with very smart control of boost and very sensitive knock detection.

When you start to see 30psi of boost on a factory engine, and it's making amazing hp and decent mpg, the reason is the tune is balanced on the head of a pin, and the second something isn't running perfectly as expected, things break.

But I trust a Honda with a little bit of boost, come on guys.

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