Topic: Small displacement high output turbo engines?

[sailor723]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

[Ex-airbalancer]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

Give a 6 cyl over a 4 cyl TC all the time in a CUV
A Highlander XLE would probably be #1 on my list
The seats are not contoured , they are pretty flat , which is great if you have bad hips 

[tortoise]

http://www.autos.ca/forum/index.php?topic=97374.0

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[Great_Big_Abyss]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

Well, it depends on how they're designed.  Engineering is simply analyzing forces and selecting materials/shapes to resist those forces over time.  A small engine can have a high specific output and be reliable if the materials and shapes it uses are engineered to withstand those forces for a long time.  The corollary is that that motor will be expensive to be.  For example, an engine builder may have to option to use a cast then machined piston, a forged then machined piston, or a piston machined right from billet material.  Each type of manufacturing process increases strength and longevity, but also cost.

In the past when engine makers were building relatively large, understressed engines, they were able to use weaker metals along with cheaper manufacturing techniques.  As engines get smaller, specific output grows larger, and internal engine stresses grow, manufacturers can use more advanced alloys and manufacturing techniques.  The result is a stronger engine that will last longer at a specific output, yet cost more to build.  This is why the smaller turbo engines are usually a more expensive option than a naturally aspirated 'larger' engine.  Think of the NA 2.0L in the Civic vs. the turbo 1.4L.  Or the NA 2.4L in the Sonata vs the turbo 1.6L.  Smaller but more advanced engines, more expensive to build, manufacturers must charge a premium to recoup their money from them.

[sailor723]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

Well, it depends on how they're designed.  Engineering is simply analyzing forces and selecting materials/shapes to resist those forces over time.  A small engine can have a high specific output and be reliable if the materials and shapes it uses are engineered to withstand those forces for a long time.  The corollary is that that motor will be expensive to be.  For example, an engine builder may have to option to use a cast then machined piston, a forged then machined piston, or a piston machined right from billet material.  Each type of manufacturing process increases strength and longevity, but also cost.

In the past when engine makers were building relatively large, understressed engines, they were able to use weaker metals along with cheaper manufacturing techniques.  As engines get smaller, specific output grows larger, and internal engine stresses grow, manufacturers can use more advanced alloys and manufacturing techniques.  The result is a stronger engine that will last longer at a specific output, yet cost more to build.  This is why the smaller turbo engines are usually a more expensive option than a naturally aspirated 'larger' engine.  Think of the NA 2.0L in the Civic vs. the turbo 1.4L.  Or the NA 2.4L in the Sonata vs the turbo 1.6L.  Smaller but more advanced engines, more expensive to build, manufacturers must charge a premium to recoup their money from them.

Or maybe some will just build them cheaply, pocket the premium charged as pure profit, and hope most don't self destruct until after the warranty period.

[Sir Osis of Liver]

Production 600cc motorcycle engines have been pumping out well over 100hp and revving to 15k for a while now. But they use what used to be considered exotic materials and engineering. 

[Guy]

Production 600cc motorcycle engines have been pumping out well over 100hp and revving to 15k for a while now. But they use what used to be considered exotic materials and engineering. 

Will they last 200,000 km without a rebuild?

[sailor723]

Production 600cc motorcycle engines have been pumping out well over 100hp and revving to 15k for a while now. But they use what used to be considered exotic materials and engineering. 

Will they last 200,000 km without a rebuild?

......and how many of them are daily drivers with often less than perfect maintenance?

[Jaeger]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

If you're going to drive the thing for 3-5 years don't sweat it - a turbo will be fine.  If you plan to drive it for 10, find something a V6.  Particularly if you are looking for a larger CUV.

[tpl]

For MOST of the people who just do commuting and family stuff in their cars the only problem with small turbo engines will be maintenance.   Maybe it is time for car maintenance to be handled like aircraft maintenance...don't do the maintenance on time...don't fly.
This will be expensive but then the cars of the next decade with the new badly thought out CAFE numbers will be expensive in themselves.

Electric cars with fewer moving parts...ok, cheap to maintain. But just wait until governments see what has to happen to electricity prices to make up for loss of gas taxes.  Not to mention the costs potentially of increasing the available amperage to a large proportion of houses and apartment buildings.   

[Sir Osis of Liver]

Production 600cc motorcycle engines have been pumping out well over 100hp and revving to 15k for a while now. But they use what used to be considered exotic materials and engineering. 

Will they last 200,000 km without a rebuild?

......and how many of them are daily drivers with often less than perfect maintenance?

They will go pretty far without a re-build. There is a trade off between specific output and longevity, but cars aren't revving to anywhere near 15k either.

Bikes get about the same love and care as cars get from the general population.
 

[mlin32]

I wouldn't worry about it. With proper care and maintenance, a lot of car components, drivetrain included, are more durable than ever. Small displacement, turbocharged motors have been out for about a decade now, and there haven't been widespread horror stores.

Plus, you're not beating on it everyday, I presume. These kinds of engines are the norm in Europe where they drive harder than Canadians and Americans, and no massive horror stories there (except the timing belt on the VW EA113 motor.....)

[dkaz]

There are a handful of high output sport bikes with over 160,000 km on them no problem. They are built to last, but most sport bike riders are casual and/or fair weather riders, so these bikes don't end up seeing those kinds of kms.

You look at a more normal bike like a Suzuki 650 that produces 75 HP that's on the well loved VStrom with many older ones on the road easily 200,000km+.

I think old 2 stroke motors were known for requiring frequent rebuilds, maybe every 30,000km. But you'd have a little 200 motor that produces 42 HP.

[84im]

Given the choice, I'd prefer a V6 over a turbo 4.  A while back I test drove a 2012 RAV4 with the V6 engine.  I was really impressed with the engine, but not so much with the rest of the vehicle. 
I like the sound of a V6, compared the a turbo 4 and adding a turbo adds complexity, which means there are more things to go wrong.
Turbos have come a long way and their life expectancy has improved dramatically.  I recently read an article that stated modern turbos should last as long as the engine.  I'm not sure I believe that one.  Time will tell, I guess.

Even though I prefer a V6 I just purchased a used 2015 BMW X1, with the turbo 4.  I would have loved to find one with the turbo straight 6, but those are hard to find and tend to be loaded with options and expensive. 

[Gurgie]

My 30yr old Porsche has a 2.5L 4cyl turbo that still runs strong on the original turbo!! You'd think with newer technology & engineering that these new turbo engines would be fine for what they're designed to do. Also, they're not boosting them crazy amounts, probably only in the 10 - 12psi range (too lazy to look it up), so that's not a huge amount of boost to stress the engine.  Even the engines themselves are running combustion ratios in the 10:1 range, again, not overly stressful.

[Jaeger]

Your 30 year old Porsche isn't a 5 or 7 passenger SUV.

[EV Dan]

In starting to shop for a new CUV I'm seeing more and more big vehicles with very small (by traditional standards) engines. Yesterday I looked at a large, 3 row Volvo XC90 that was powered by a  4 cyl turbocharged and supercharged 2.0L putting out 306 hp. I realize that this trend is widespread as manufacturers scramble to meet ever tighter CAFE standards but I have to wonder......Will these things turn out to be grenades just waiting to go off?  I mean, I'm not anti new technology but I have to think wringing that much power out of that little displacement has to increase the stress on the engine.   

Give a 6 cyl over a 4 cyl TC all the time in a CUV
A Highlander XLE would probably be #1 on my list
The seats are not contoured , they are pretty flat , which is great if you have bad hips 

There is a reason Toyota-Lexus are #1 in the reliability study RR posted everywhere yesterday. If I were shopping in this class I'd go V6, no DI and no Turbo. It will take regular gas and go half a million km with due maintenance. In case of lease I wouldn't care much tough.
Hybrid is another great option (again, most don't have DI or turbos)

[Fobroader]

Your 30 year old Porsche isn't a 5 or 7 passenger SUV.

^^This. Your 944 doesn't weigh as much as a 7 passenger SUV loaded down with the largest strollers that money can buy. I think these engines will be highly stressed just trying to merge into traffic.

[Gurgie]

Your 30 year old Porsche isn't a 5 or 7 passenger SUV.

^^This. Your 944 doesn't weigh as much as a 7 passenger SUV loaded down with the largest strollers that money can buy. I think these engines will be highly stressed just trying to merge into traffic.

Correct, it's not!! But at the same time it's only putting out ~220hp at the crank, so it's not as powerful... and it's 30yr old fackin technology... actually probably 35yr old, since they designed it 1st before they put it into production in 1986. The point is that with the advances made over the past 35yrs that these new engines will be fine, they might get beat on to merge into traffic, or for passing maneuvers once in a while, but if properly maintained there's no reason to think they won't run trouble free for 10+ years. The cooling systems nowadays alone are MUCH better which helps with engine longevity, and newer turbos have come a long way in durability, we're not talking a 1988 Dodge Daytona with it's disposable turbo    Also, lets say an average person drives 25,000kms in one of these SUV's per year, how many of those kms will be under high stress situations?  10%? 15%? 20%?  It's not like someone will be beating on this thing 100% of the time.

[Sir Osis of Liver]

I so don't get this argument. Engine specific outputs have changed since the beginning.

Leno's recent video of his 1918 Stutz showed off its 5.9L, four cylinder which put out a massive 60hp, which was brilliant for the time, even for an expensive car like the Stutz. By 1927, the 3.3L four cylinder in the cheapo Ford Model A was putting out 40hp, and it didn't benefit from the four valve design or dual plugs per cylinder of the Stutz.

Edit. I should add that the 1937 Ford has an entry level 2.2L V8 that had a 60hp output, but that was a horse of a different colour.