Vehicle complexity and reliability - Your opinion

[ExtraSlow]

I'm pretty active on truck forum, and it's a common refrain that a V8 truck will be more reliable than a turbocharged gas engine. This opinion was also brought up on this forum when discussing Volvos super-turbo "twincharged" engine.

I doubt solid statistics can settle this argument, so let's see what everyone thinks.

Are turbocharged, supercharged, or in some cases both, engines less reliable than naturally aspirated engines in current cars, or has the technology and engineering been proven long enough that reliability is about the same?

I sure know I enjoy driving a turbocharged engine more than naturally aspirated, especially in a pickup, but that's beside the point.

[Mitsu3000gt]

IMO these days it isn't much of an issue so long as you're buying from a reliable brand (I can see how it could be a bigger issue on American trucks/vehicles). I think in the past, it would be fair to say forced induction cars were usually less reliable overall.

Any time there are more parts, there is technically more that can go wrong but that isn't limited to forced induction hardware. These days it's pretty unlikely those sorts of things outright fail in a reasonable/common vehicle ownership period of say roughly 4-7 years. People keeping cars 10++ years, you're probably just as likely to have a different major component fail as you are a turbo. I suspect FI vehicles are still slightly less reliable, just not to any significant degree that would impact the average consumer.

There are other factors too, for example if you have a N/A engine that has to be driven really hard all the time just to keep up with traffic, it's going to be under more stress than a similar motor riding a wave of low RPM torque from its turbo.

Volvo's engine might be more of a special case with it's unnecessary over-the-top complexity, I wouldn't be surprised if that had below average reliability as a result. A standard single-turbo, simple 2.0T motor or something similar from a good manufacturer though I wouldn't ever worry about. Vehicles in general these days are so much more reliable overall than they were even 10 years ago. Many of the brands now that have built their reputation on predominantly boring, reliable vehicles (Honda/Acura, Toyota/Lexus, etc.) are using forced induction in some of their most popular volume-sellers, and they definitely wouldn't be doing that if they thought it would damage that precious reputation. It wasn't even that long ago though where it was very rare to see those brands utilizing FI, but I think we're at a point now that reliability isn't a significant concern. I think when you have brands like Honda and Lexus putting a turbo in their volume sellers, its a good testament to that.

[rage2]

Just more shit that can break on a turbo engine so ya, it’s either same or less reliable. If you look at all the million mile cars out there, they’re all NA. Still doesn’t mean much haha.

[ExtraSlow]

On ford half tons particularly, they sell about 65% turbo engines, and much fewer naturally aspirated, so if there were huge reliability issues there, I think it would be pretty obvious.

[firebane]

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I'm pretty active on truck forum, and it's a common refrain that a V8 truck will be more reliable than a turbocharged gas engine. This opinion was also brought up on this forum when discussing Volvos super-turbo "twincharged" engine.

I doubt solid statistics can settle this argument, so let's see what everyone thinks.

Are turbocharged, supercharged, or in some cases both, engines less reliable than naturally aspirated engines in current cars, or has the technology and engineering been proven long enough that reliability is about the same?

I sure know I enjoy driving a turbocharged engine more than naturally aspirated, especially in a pickup, but that's beside the point.

Anything that is going to add strain to a vehicle will immediately make it less reliable.

NA has its place as does forced induction but I think I'd rather go with a SC over a turbo and then possibly NA.

[Skrilla]

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On ford half tons particularly, they sell about 65% turbo engines, and much fewer naturally aspirated, so if there were huge reliability issues there, I think it would be pretty obvious.

The Gen1 Ecoboost was a disaster for a lot of people, including the 4 trucks we had. Gen2 is considerably better, but id still trust the 5.0 for longevity. Haven't had a lot to do with new cars that are turbo or supercharged, except my wifes CRV, which hasn't seen enough use to talk about. There definitely have been some rock solid forced induction engines used over the years, 3.8SC GM engine comes to mind, seen and drove many cars with that motor and well over 350k with no major work. Owned a few turbo VW's over the years, have always been reliable drivetrain wise, but not so much on other fronts.

[vengie]

More moving parts= More potential fail points

[ExtraSlow]

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Anything that is going to add strain to a vehicle will immediately make it less reliable.

This is a good point too. And as a follow up question, I wonder what places "more strain" on an engine, running at 4500rpm naturally aspirated or 2000 rpm with a turbo? I feel like the turbo engine is under less strain, and those options are very realistic highway towing scenarios.

[Disoblige]

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This is a good point too. And as a follow up question, I wonder what places "more strain" on an engine, running at 4500rpm naturally aspirated or 2000 rpm with a turbo? I feel like the turbo engine is under less strain, and those options are very realistic highway towing scenarios.

It depends how the parts are engineered to deal with said strain. More parts = more points of failure is a basic way to look at things, although it is accurate a lot of the time. But dig deeper on why certain cars are more reliable even with more parts vs. others with less.

[Buster]

I bet the additional heat from a turbo is a bigger concern than the additional parts

[heavyD]

While there's no doubt that turbocharging has come a long ways since the 80's but regardless of the improvements they are more complex, run hotter, and require more parts that can fail. There's a reason Toyota has maintained high reliability over the decades and it's largely because until recently they used strictly NA engines of slightly outdated design compared to the Germans and even domestics. Honda only recently (latest Civic and Accord) started adding DI and turbocharging to their vehicles while many competitors have been using this tech for over a decade. The Germans get a lot of flack for reliability but that always comes when you are the first to start mass producing new tech.

[The_Rural_Juror]

Why are Porsches so reliable then?

[Skrilla]

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While there's no doubt that turbocharging has come a long ways since the 80's but regardless of the improvements they are more complex, run hotter, and require more parts that can fail. There's a reason Toyota has maintained high reliability over the decades and it's largely because until recently they used strictly NA engines of slightly outdated design compared to the Germans and even domestics. Honda only recently (latest Civic and Accord) started adding DI and turbocharging to their vehicles while many competitors have been using this tech for over a decade. The Germans get a lot of flack for reliability but that always comes when you are the first to start mass producing new tech.

Solid point, never looked at it that way, the entire Toyota lineup is NA, or damn near. Seems they are the only ones holding on to that.

[Mitsu3000gt]

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Solid point, never looked at it that way, the entire Toyota lineup is NA, or damn near. Seems they are the only ones holding on to that.

Honda used a 2.3L Turbo in the Acura RDX from ~2007-2012, Toyota has been using a 2.0T in the Lexus NX since ~2014, so they have been dabbling for years but it but it wasn't really commonplace until ~2016 or so. Like I said above, I don't think they made the switch until they were confident it wouldn't sour their reliability reputation. Being able to get perfectly reliable turbo powerplants in generic vehicles have made them much more attractive IMO, compared to the brands slower to adapt but charge the same or more money (like Mazda).

[Sentry]

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Why are Porsches so reliable then?

Hahahahahahahahahahahahahahahahahahahahahaha

[rage2]

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Why are Porsches so reliable then?

Great marketing team obviously.

[msommers]

What are industrial or commercial applications using predominantly? Trains, shipping boats, semis etc.

[Mitsu3000gt]

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What are industrial or commercial applications using predominantly? Trains, shipping boats, semis etc.

Turbo diesels in almost all of them, it's hard to get the kind of low-rpm torque most heavy machinery relies on without one. Locomotive engines are kind of cool in that they are usually V12 2-stroke turbo diesels (lots of the really huge motors are 2-stroke).

This is what a container ship's turbo looks look like:



Farm tractors also have turbos, and even those little landscaping Bobcats have turbos and like 75HP haha. Most things with diesels are going to have a turbo, and most commercial applications use diesel engines.

[firebane]

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What are industrial or commercial applications using predominantly? Trains, shipping boats, semis etc.

They use turbos because you can use a small displacement type engine and produce more power.

Superchargers will rob MORE power before making it back.

[Tik-Tok]

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until recently they used strictly NA engines

2.0L MR2 would beg to differ.