Wards Ten Best Engines For 2008

[newclasshero]

Originally Posted by Kennyboy

It's good to hear two of GM engines made the list. Last year, not even a single GM engine made it.

I was just thinking that I seemed to remember that.

[mkaresh]

Originally Posted by Michael_S

The 6.0 in the Hybrids was motified to use the Atkinson combustion cycle, which is also used in the combustion engine in the Prius and a few other hybrids.

Otto cycle (normal gas and diesel engines): fuel and air are compressed the same amount they are expanded. If they're compressed 10 to 1, they expand 10 to 1 before exiting through the exhaust valve.
Atkinson cycle: it provides less power but more efficiency, because fuel and air are expanded more than they are compressed. They might be compressed 10 to 1 and expanded 12 to 1, which extracts more energy per unit of fuel.

That's why the 6.0 in the Tahoe and Yukon hybrid only makes 332 horsepower while every other current GM truck or SUV with the 6.0 gets at least 350 horsepower.

Is the 332 for the engine alone, or the engine plus the hybrid motors? Other hybrid sellers have gone both ways. For example, the engine in the Highlander Hybrid is rated at 268 horsepower with the electric motor, and 209 without it.

The 332 seems low enough to be without including the electric motors, but somewhere recently I read that this figure includes the output of the electric motors. Which could be wrong.

Any idea?

[b4z]

Ever notice how an engine makes Ward's one year and it's off the next? Replaced by the latest unproven design.Ward's Top 10 carries about as much weight as MT's COTY.

[mtndrew1]

Originally Posted by Michael_S

I don't know why, but as far as I know no automakers are using that type of engine except in some hybrids. I'm not sure why. Most of my knowledge on engines is from these forums and wikipedia, so I'm sure others who know more could fill in the details.

Atkinson cycle engines are indeed more efficient, however they have a severe lack of low-end torque.

The reason you see them primarily in hybrids is that the electric motors mated to them excel in low-end torque. Thus, the efficiency of the gas engine can be realized with the electric motor stepping in to help the torque situation, so that the vehicle doesn't feel underpowered to the driver.

-Drew

Edit: http://everything2.com/index.pl?node=Atkinson%20Cycle

There's a link to the description of the cycle and why it's lacking in low end torque.

[Michael_S]

Originally Posted by doh

by allowing the mixture to expand to a larger volume than was drawn into the cylinder, more energy was extracted giving greater fuel efficiency than the Otto-cycle

A cool example is at the link, http://www.keveney.com/Atkinson.html

Thanks for the example. But I-Love-Pontiac was asking why the Atkinson is not used in more non-hybrids. I was responding that I don't know. If it really does boost efficiency, why not replace GM's 2.4 liter Ecotec with a 3.0 liter Atkinson V6 that gets the same 169 horsepower but 15% better mileage?

In another thread, someone suggested that Atkinson totally ruins low end torque, and so it's only usable in hybrids where an electric engine can make up for the gasoline engine's weak low RPM power. I don't remember who said it... Xenon, maybe? But either way, it was just a guess and neither he nor I know for sure why the Atkinson cycle is so rare in modern engines.

[EDIT] Obviously, mtndrew1 provided the information in the post right above mine. Thanks!

[Koasterking]

Congrats to GM! Lets make more like 'em!

[big swede]

Originally Posted by b4z

Ever notice how an engine makes Ward's one year and it's off the next? Replaced by the latest unproven design.Ward's Top 10 carries about as much weight as MT's COTY.

I'm not sure what you are getting at. There are plenty of proven performers on there, in fact the only all new unproven motor on the entire list is the twin turbo BMW motor that's such a gem that it would be a shame had it not been picked. Possibly the Diesel Benz, but I don't know about that one. The VQ has been on there since it's inception in 1995 because of constant refinement and improvement.

The only reason engines get "kicked" off is because a manufacturer builds a great engine and then leaves it to die on the vine so it get's surpassed by better more improved engines. I keep hearing this unproven thing but realistically engines are not black science and pretty much all the manufacturers make very reliable engines. Engines that just blow up are pretty much a thing of the past and a true freak of nature lemon when it does happen. More common are accessory failures or leaking gaskets.

[E. Haskell]

Where is the LS3??

Road and Track recently compared the LS3 to V8s from the Aston Martin Vantage, Ferrari F430 and Audi R8....and it WON!

[big swede]

Originally Posted by E. Haskell

Where is the LS3??

Road and Track recently compared the LS3 to V8s from the Aston Martin Vantage, Ferrari F430 and Audi R8....and it WON!

I think the LS3 and the turbo ecotec might have gotten left off because they are just too new and not many people have experienced them.

[Gm786]

Its good to see those 2 GM engines on the list. I'm just trying to figure out if Ward's talking about the regular 3.6 liter or the DI 3.6 liter.

[blank disk]

Originally Posted by ChevyRules

I don't think the Vortec 6.0 V8 is worthy of the award IMHO. It is just a detuned version of the regular one mated to the special transmission. Unless I am missing something when it comes to the Two Mode system......

Good point, I don't get the award for the 6.0L either. Nothing special in the engine, just the transmission.

How many hybrid Tahoes does GM expect to sell anyway? You have to spend thousands to save $600/year. That does not seem right to me, to spend that much cash to move from 16mpg avg to 20mpg avg for a 4WD. And the more hwy you drive, the less the benefit, as it is mostly gained in city driving.

[mtndrew1]

Originally Posted by blank disk

Good point, I don't get the award for the 6.0L either. Nothing special in the engine, just the transmission.

How many hybrid Tahoes does GM expect to sell anyway? You have to spend thousands to save $600/year. That does not seem right to me, to spend that much cash to move from 16mpg avg to 20mpg avg for a 4WD. And the more hwy you drive, the less the benefit, as it is mostly gained in city driving.

I think they're lumping the hybrid drive into the "engine." I believe the Prius 1.5L won one year as well (might have been the 1.3L Honda IMA), and it's also unremarkable except for its hybrid application.

From everything I've read so far on the GM two-mode 6.0L setup, it's silky-smooth and startlingly powerful while returning excellent economy for the monstrous size of the vehicle.

Ward's appears to be rewarding GM's heavy engineering into this powertrain, as opposed to just singling out the gas engine. I think this is appropriate and worthy of the award.

-Drew

[Uzzy]

Originally Posted by HoosierRon

Do Canadians find this offensive?

No, I don't. I thnk it's funny.

[ctaylorzl1]

^^^ I have that t-shirt, I bought it and a "Midwest, we aint afraid of no coast" shirt!

And as for the enignes, I pretty much agree with them they are all great engines, the Honda 3.5 seems OK, but nothing stellar like the others, but the one I cannot believe is on there is the Ford 4.6 V8, that engine has been underpowered and overrated since it became avaliable in 96!!!! That engine always has been a dog! If anything they should have given that spot to the LS3, it has a extra 130hp and gets similar mileage.

[Xenon]

Originally Posted by spaz

from most reviews the GM LNF 2.0 DI turbo seems like a much more impressive engine than the VW/AUDI FSI 2.0T

Same can be said with any engine with more power. And the LNF's output isn't exactly amazing considering that Mitsubishi has gotten more power out of their now retired 4G63 engine for years.