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]

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]

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]

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]

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]

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]

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]

Why are Porsches so reliable then?
Hahahahahahahahahahahahahahahahahahahahahaha

[rage2]

Why are Porsches so reliable then?
Great marketing team obviously. :rofl:

[msommers]

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

[Mitsu3000gt]

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:

http://kemplon.com/wp-content/uploads/2015/08/2.jpg

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]

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]

until recently they used strictly NA engines

2.0L MR2 would beg to differ.

[schocker]

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

Most of the fired og equipment I buy is large displacement with turbochargers so that it can run at a low RPM. Last one was a 7.6 L w/ turbo producing 167 hp on NG/Propane. Another one is 115 L producing 1480 hp at iirc 1200 rpm.

[msommers]

So the FI applications used for industrial purposes are simply because of a HP/TQ requirement rather than a longevity/reliability aspect?

If so, it certainly seems that FI is used because they have to, not because they want to.

[Mitsu3000gt]

2.0L MR2 would beg to differ.

And the Supra.

[Mitsu3000gt]

So the FI applications used for industrial purposes are simply because of a HP/TQ requirement rather than a longevity/reliability aspect?

If so, it certainly seems that FI is used because they have to, not because they want to.

Size/efficiency is also a big reason, especially for engines that will be running for hours on end. Turbos get you more power out of a smaller engine, which means less weight and less space. They are also more efficient than a much bigger motor without a turbo, which is a huge consideration when you're making a long-distance trip (i.e. container ship). Even tiny efficiencies save shipping/transport companies millions of dollars. Same principles as passenger cars for the most part, just on a much larger scale.

They don't necessarily have to use turbos, it's just way better if they do. Any reliability concerns are going to be far outweighed by cost savings from performance gains, weight savings, and space savings. And would a giant N/A V12 be more reliable than a turbo 6cyl making the same or more power and with likely a much more usable power band? Probably not if we're going off the basic idea that more parts = less reliability.

[M.alex]

Can easily be just as reliable. My daily driver is an 04 mustang cobra with basic mods (ported, pullied, intake, tune, exhaust, etc.). over 200k miles on it; stock clutch, no mechanical issues other than having to change TOB 3x (common issue) and rear pinion seal once.

[ThePenIsMightier]

I don't think engine reliability plays as much of a significant role at all anymore in modern vehicles. So, I wouldn't put too much weight into the question.
Still, I'd agree that NA should be slightly more "reliable".



Why are Porsches so reliable then?

I lol'd so loud! Then gave rep.

[max_boost]

Budget baller Lexus vehicles are reliable :D

[Twin_Cam_Turbo]

I’d say electrical reliability is more important to talk about than mechanical reliability these days.

[ExtraSlow]

Current responses are split pretty evenly. Interesting.

[killramos]

Turbo certainly doesn’t scare me. It’s not the 90’s.

[heavyD]

2.0L MR2 would beg to differ.

Well I owned an MR2 but I don't think this conversation is centering around decades old low volume cars as we are talking about the use in high volume cars today.

[revelations]

Forced induction vs NA - you would have to compare the same vehicle from the same year.

On average, as far as turbo - you have:

- more spinning parts
- more heat near the engine/bay
- more sensors
- more pneumatics
- more cooling/oil lines
- intake systems that have to be able to handle, say 20 psi without leaking, this includes inter-coolers

Its going to be an obvious answer.

The BIGGER question is:

Have there been IMPROVEMENTS to turbo/super charging the last 20 years? (ie better reliability)

[heavyD]

I’d say electrical reliability is more important to talk about than mechanical reliability these days.

I suppose the importance of electrical reliability really depends on how much you care about them at present time as they still make for a paltry 2% of all automobile sales. Kind of a non-factor at the moment IMO when pretty well all of us are still rolling in ICE powered vehicles.

[never]

I suppose the importance of electrical reliability really depends on how much you care about them at present time as they still make for a paltry 2% of all automobile sales. Kind of a non-factor at the moment IMO when pretty well all of us are still rolling in ICE powered vehicles.

I assume TCT is referring to the electrical system on any vehicle...given how much more complicated and integrated they are these days.

[90_Shelby]

Forced induction vs NA - you would have to compare the same vehicle from the same year.

On average, as far as turbo - you have:

- more spinning parts
- more heat near the engine/bay
- more sensors
- more pneumatics
- more cooling/oil lines
- intake systems that have to be able to handle, say 20 psi without leaking, this includes inter-coolers

Its going to be an obvious answer.

The BIGGER question is:

Have there been IMPROVEMENTS to turbo/super charging the last 20 years? (ie better reliability)

Something to consider with modern NA engines includes the addition of complex components and more moving parts that were brought to mainstream engines much more recently then forced induction. Not to say that a lot of these components aren't also in use with modern FI engines but a lot of these systems were developed in order to increase fuel economy or increase power with smaller engines and I would question the reliability just as much, if not more then the addition of a turbo or supercharger.

I would question, how reliable are some of these systems in comparison to FI?

-VANOS, other variable cam/valve timing
-MDS, multi displacement cylinder activation
-DI and high pressure fuel pumps, carbon build up
-Carbon buildup
-DISA variable length runner intake manifolds
- Variable compression ratios
-8000+rpm engines

[revelations]

Something to consider with modern NA engines includes the addition of complex components and more moving parts that were brought to mainstream engines much more recently then forced induction. Not to say that a lot of these components aren't also in use with modern FI engines but a lot of these systems were developed in order to increase fuel economy or increase power with smaller engines and I would question the reliability just as much, if not more then the addition of a turbo or supercharger.

I would question, how reliable are some of these systems in comparison to FI?

-VANOS, other variable cam/valve timing
-MDS, multi displacement cylinder activation
-DI and high pressure fuel pumps, carbon build up
-Carbon buildup
-DISA variable length runner intake manifolds
- Variable compression ratios
-8000+rpm engines

Thats a whole different thread and I completely agree there have been longevity issues for many of these (VANOS) ....

[mr2mike]

2.0L MR2 would beg to differ.

Hitting a former mr2 owner with his own meds. Lol

- - - Updated - - -

Ask all the turbo BMW 3 series owners that need their high priced maintenance done that's related to the turbo on the motor.
Most decide to trade in rather than fit that bill.

Another aspect in the positive side is newer oil technology can keep turbo cars going longer.

[Twin_Cam_Turbo]

I assume TCT is referring to the electrical system on any vehicle...given how much more complicated and integrated they are these days.

Correct

[heavyD]

Correct

I think electrical reliability is pretty sound these days as a lot of wiring has been replaced by CAN bus communications and the like. I would like to think in this day of solid state manufacturing we are past the days of bad ecu capacitors, etc.