GM Announces Best-In-Class Power Figures for 2011 6.6-liter Duramax V-8 Diesel

GM Announces Best-In-Class Power Figures for 2011 6.6-liter Duramax V-8 Diesel

Just last month, Ford announced that its all-new 6.7-liter Power Stroke V-8 diesel would pound out an incredible 390 horsepower and 735 pounds-feet of torque, giving the F-Series Super Duty best-in-class power ratings for heavy-duty pickups. Now, that short reign is over, according to General Motors.

GM announced that the updated 6.6-liter Duramax V-8 diesel for the 2011 Chevrolet Silverado and GMC Sierra HD pickups will make 397 hp (at 3,000 rpm) and a mind-blowing 765 pounds-feet of torque (at 1,600 rpm). That’s 105 more pounds-feet of twist than the 2010 Duramax V-8. We just warped our keyboard writing that.

The Duramax V-8, dubbed “LML" internally, is the latest generation of GM's HD diesel since it was introduced in 2001. Sixty percent of its parts are new, and Duramax chief engineer Gary Arvan said it will be 11 percent more fuel efficient than the previous LMM Duramax.

Duramax 6.6-liter LML Diesel

A different dyno-rated version of the 6.6-liter Duramax is offered in GM’s HD chassis cab and box-delete models. It’s based on the same new architecture and includes most of the same features as the pickup version, but it is engineered to meet federal certification standards for incomplete vehicles, including the incorporation of a different exhaust-gas recirculation system. It’s rated at 335 hp (at 3,100 rpm) and 685 pounds-feet of torque (at 1,600 rpm).

There are no changes in final power ratings for GM’s 6.0-liter V-8, which continues at 360 hp (at 5,400 rpm) and 380 pounds-feet of torque (at 4,200 rpm).

HD Pickup Truck Comparison Chart


I can see the Howie Long commercials now... "390 or 397? I may not be very smart but I'll take the 397!"

I knew that GM was going to bump up the hp/tq just to outdo Ford, but I figured they would at least break the 400hp mark. Considering the range of available gearing Ford has vs GM for their diesel, the Ford might actually end up being the better performer.

I also figured they would bring out some kind of replacement for the old as dirt 6.0L (like an iron block version of their 6.2L)

Overall, I'm somewhat disappointed. Well, not really disappointed, but I'm less impressed than I thought I would be.

wow!...i knew they would do anything to try to beat ford.

i think this is a decent amount of stocked power, i know that we are all waiting to see who will break the 400HP barrier.

but we all also know that with a couple of aftermarket parts and tweaks we can get way more out of a diesel engine.

this leaves dodge as # 3 in power but # 1 in reability cummins POWER!!!.

i wonder if cummins will design a v8 and keep the I6 for the 1/2 tons THAT WOULD BE F'ING awesome!!!!

jejejeje!!..GO RAM!!

Well done GM !

30 more torque then Ford ! And 105 more torque then the previous Duramax... Very impressive ! The Duramax remains the power champ !

Cool news. I knew GM would out due Ford with a simple ECM tweak or two.

This is interesting, but anyone in the aftermarket diesel world knows these new numbers from Ford and GM dont mean much. Actual power to the rear wheels is a whole nother thing. These engines have SO much more in them then what is rated from the factory. These are just the numbers they can manage will meeting emissions.

I would still rather have the 6.7L Cummins. Its a more of a diesel guys diesel than these quite civil engines.
The next Cummins engine should blow these Ford and GM numbers away no problem. The 6.7L Cummins is already EPA rated for 750 lb-ft in medium duty trucks and machines. The new 6.7L Cummins is said to be going to have twin turbos and some serious new tech.

Anyway, great news!! I hate waiting games.

Cant wait for the HD shoot-out!! Whens that gonna be again?

GM will now celebrate their win by reorganizing management.

I'm not surprised at the 397 HP, but I was a taken back by the 765lb twist, coupled with the new frame it should be a great truck.

its impossible to make an educated guess on which truck is best, just by looking at the numbers.

What i'm waiting for is a side by side shoot out, with towing test and MPG test while hauling and towing.

Thanks Mike! Any chance you know the weights of the 6.7 Powerstroke and new Duramax engines? I wonder if the CGI block in the Ford saves a significant amount of weight.

cant wait to see cummins answer to this

You knew this was going to happen. Anyway, Dodge/Cummins has an advantage in that it doesn't need urea, but I would be willing to wager that if they want to run with Ford and GM, they will have to use it.

Hmmm so currently get 12 mpg add 11% = 13.3 mpg.

Based on what we've read here recently woudl expect Ford to have best mileage. Gm more tq. Ram best.... looks?

@ Big Bob

It may well turn out not using urea will hurt Dodge. It appears they may have the worst mileage of the three. They avoided the urea route knowing it would hurt mpg.

If the mpg of the new Ford diesel hold true, the boys won't care about the urea factor.

We'll find out I guess.

WOW. I was expecting to see bigger numbers then the Ford, but not that much. This torque war is starting to get insane!!!

@Big Bob. Don't count on Cummins needing urea. Cummins ONLY builds Diesel motors and rumors coming from them are saying their next gens, which are due in the next couple of years, will need little to no emission equipment. I guess they are modifying the way the ignition occurs, causing much more efficient burn.

@ power kid

Cummins = Most reliable

I still want to see these Urea engines tested in cold weather. Remember Urea freezes at around 20 degrees.

How long is it going to take for the urea to thaw after you start these engines. I'm guessing they won't be able to be used a full power until the urea is almost free flowing.

Ram is best at being conservative with its looks. If you like conservative styling the Ram is best looking. If you like government styling, GM is the best looking. If you like bold and tough styling, Ford is the best looking.

765 torque with a new kick ass frame ! Sign me up !

the towing capacities between the ford and the chevy arent rated very well when they are comparing an F450 to a 3500 Silverado but its nice to see that GM is letting these engines put out the power they should be making right out of the box, lets just hope the fuel mileage is more than 11 MPG unloaded like the LMM is

"I can see the Howie Long commercials now... "390 or 397? I may not be very smart but I'll take the 397!" - Dave

I can see the Mike Rowe commerical now....."It take's a real truck to do a dirty job".


If bold and tough styling equals that ugly ass grille and headlights Ford has on their new super-duty, then you can keep it...

@powerkid, I been getting 23 MPG HWY (empty) on my 08 Duramax 4x4 1 ton. I'm sure I would be able get 25 when I get my 2011 Duramax.

Great job GM! I personally would feel more confident towing 24k with GM then a Ford, since it's all new chassis and they sure wouldn't make it any weaker then outdated competition, and with best power and engine brake it's the best performance HD truck for 2011.

OH, more info on DEF or Urea. Ford has inline heater, which i'm sure all will,rather GM,ford, on

There is going to be a winter version of DEF. Because regular urea or DEF freezes 11 degree F.
For all you worried about DEF in winter. The winter DEF freeze point is like -20F (thats minus 20)

DEF will run about 2-3.00 a gallon,
Lots may moan over it and say i'm not buying a truck that uses DEF or say its just another tank to fill...i'm sorry but DEF in today's world is YOUR FRIEND!
It means motor can run better,more power,around 20% increase in mileage.
And with the small cost of urea and the Gain of All the extra power and around 20% in MPG's..Hell yeah!!!

Extreme winter testing was done at least on the Ford.

The 2011 Ford Super Duty was tested in -40 degrees and +130 degrees F.

Those grilles and headlights are not just tough they are Ford Super Duty tough.

Ford Ford Ford Ford Ford!!!!!!!!!!!!! Ford this. Ford that. Frank and Dave are killing this blog with their Ford posts!

GM is the best and the most powerful. I know you Ford fanboys will sleep a little less comfortable tonight knowing that GM is the most powerful truck. 397 hp! Put that in your pipe and smoke it, Frank!

thank you for your post, bobby1971

Any idea on what the available rear end ratios will be with the diesel?

Ford offers from 3.31 to 4.30 with the powerstroke, where traditionally GM has only offered 3.73 with the duramax. That can be a big disadvantage in fuel mileage on one end and power getting to the ground on the other end.

Also, any news about the HD vans and the 2500 suburban/yukon possibly getting a version of this engine?


If bold and tough styling equals that ugly ass grille and headlights Ford has on their new super-duty, then you can keep it...
Posted by: maxx

Right on! I am sick of Dave and Frank's GM bashing!!!! This has got to stop. Ford stinks for styling, always has always will. Fords have been hit with an ugly stick and only sell well because they sell to the fleets. GM styling is the best looking. I love the grille and the interiors have Onstar. Inside and out it GM is the best looking. Enuff said!!!!!!!!!!!!!!!!!!

Frank just needs to stop his anti GM posts. I am sick and tired of these childish posters talking about Ford and the bailouts everytime. I hate Ford but I am not on here bashing Ford all the time! I am just telling you the facts that Ford is ugly and weak with less power and has less technologies. Does Ford have Onstar? I don't think so.

I say this to every little man who makes nasty remarks about GM trucks, buy a Ford if you like Ford, buy a Dodge if you like Ram. But stop with the gosh darn GM bashing and let people make up their own minds on what truck they want to buy.

Most of all, this is the real reason Ford did not want to do the tug of war. It has less power and they did not want to be exposed! Plain and simple. So everyone just be quiet until the shootout and stop bashing GM the most powerful truck every two seconds. God bless GM.

as a Ford fan, i am completely blown away by the new diesels from Ford and Chevy... this is INSANE. i mean, think about it guys. between the two, 735 ft lbs is the least amount of torque. let that soak in for a second. these nnumbers were un heard of a few years ago. does anyone know what the gear ratio is for the Chevy, and how it will lay all its new power to the ground??? i WILL give credit where credit is due, so PROPS to the new DMAX. my gosh. Now im excited for Cummins to make a new one for the ram. It will be nuts. but yeah, to all the Chevy fans, congrats. no hate from this Ford guy. the shootout will be insane

"Does Ford have Onstar?"

No, because Onstar is proprietary to GM vehicles.

That's like me saying:

Does GM have SYNC? I don't think so.

Like Dodge is changing to Ram, Ford is gonna go under a new name in the coming year. Instead of FORD, it's gonna be JUNK. lol. I love them new Chevy's.

Chevy vs Ford

@ bobby1971, who the hell needs Onstar, now a days everyone has a cell phone. Plus after a year you have to pay for onstar. Onstar should be free for the life of the vehicle when you pay that much for a vehicle.

Comments on this blog should be related with the topic which is Chevrolet/GMC. Yet I see alot of Ford here.....

This is not a debate here, if you feel that Ford is better, great cause NO ONE CARES!!
I'm sick of same comments on every blog, lame reasons how Ford is better, Yes Government bailed GM out SO WHAT??? but guess what? Ford is in bigger debt.. But again, NO ONE CARES, and don't either.

They have New DEF out. good till -20F....that usually covers most people.
Wow, thats impressive...Very impressive! Great job chevy!!
60% new parts though...same boat as ford on the engine.

Oh, that urea DEF is going to be sweet! You may call B.S. on this one...Some ford articles said they ford with 3.31's,with new diesel,when taking it easy,were getting 30mpg!!!
Now, i heard same with new chevy too!
That right there is the Bomb for either Brand. If they are reliable to boot...Cummins will HAVE to change to compete!

i think ford might be coming back with new numbers...the first numbers i heard Were not, i repeat, were not in stone...just like chevy tow ratings,ford waited and beat them....lets see if ford or cummins has something under there skirt!

BRAD, you copy pasted one of my post on the new Ford!! On the urea or least give me some credit dude!
I posted that on the DEF, Because ITS TRUE!! DEF haters,will be lovers soon!

@Paul: GMs will have a choice of a 3.73 or 4.10. A 3.42 may come later but GM has to tool up for that if they do.

i knew general mistake would have just a bit higher in numbers thats why they waited till ford released theirs so they could claim they have higher. GM does it everytime ford comes out with something. If ford was smart they would dyno the douchamax and see what it really brought at the crankshaft. HP numbers and torque are what is at the crankshaft, its alot lower once it reaches the rear wheels. BTW hp numbers doesn't sell trucks and ford has been proving it for 34 years

At the end of the day its still government motors junk. Look where GM is with O'bumble running things. No thanks. I would rather have a sister in a whore house than a brother that drove a POS Government Motors piece of crap.


I believe I saw the urea tanks have heaters, and that the truck won't do a regen when the urea tank is frozen. So, if you start the truck when it is -30, you will have full power and when the tank thaws it will do regen if it needs to.

"@Paul: GMs will have a choice of a 3.73 or 4.10. A 3.42 may come later but GM has to tool up for that if they do."

@Mike Levine, GM and Dodge both use AAM axles in their HD trucks. Dodge has offered the 3.42 for several years now. No tooling on GM's part needed.

@ mike. there is a lot of talk not only on this board, but around the internet that GM, on purpose, waited for Ford to release their power figures so that they could say their engine is stronger.... do you believe that might be the case? or are you a firm believer that the DMAX indeed makes this much power. b/c those numbers are crazy. i, myself, am a little skeptical of it as well, but i cant say they are lying till we see real numbers.

Take that all you Ford humping lovers!!! Once again, GM has the best diesel engine with the most horsepower, best in class torque, and will beat Ford and Dodge in fuel economy.

On top of that, they do it with a smaller displacement engine! 6.6 liters to 6.7 for Ford and Dodge.

Just wait until the shootout this summer when GM kicks sand in the faces of the Ford super dunce and the Dodge cummins.

I love it! Hay Frank and Lou, hows second place taste????


@me bitches...

Give up on the government loan crap..They will pay it back,GM already paid some back as well as Chrysler and Chrysler said by 2014 it will be paid back ...
Do you want Pelosi to give herself a huge raise or help out many Americans and the American auto industry ?

Ford was lucky to get a loan before the banks crashed,otherwise they would have a gov. loan too(they attended the meetings..remember)
Asian and European companies receive government loans from their gov..Even the guy who claims to be against government loans (Glen Beck) was interviewed by a auto magazine and Beck even said something had to be done to save our auto industry,but by watching his show you wouldnt know he said that.....stop drinking the kool-aid !!!

@ bobby1971,

They already covered the name game..Ram will always be a Dodge !!

Good news for GM guys...Not only do their trucks outsell Ford ,but they have more power and torque...

Bad news for Ford guys,not only do they not have the most powerful Diesel truck,as you were all happy for a day or so....Ford now has the ugliest truck too..that front, you have to be blind to like that,huge,huge lights,huge emblem...UGLY !!

But I think Dodge will have the last laugh..the new 6.4 Hemi is not out yet,and It will beat any GM or Ford gas engine,and I wonder if a more powerful Cummins is in the works..the 4500 and 5500 are coming out later this year and maybe with an upgraded Cummins..You never know,not that I really care,I am a gas engine my Dodge Hemi Ram 1500 !!

Did chevy wait for ford numbers...well, of course! Its a marketing thing/advertisement! All car/truck manufactures do it!
I do believe the duramax makes that much power! Like someone posted above, how effiecent is there transmission? How much of that power is sucked up or let thru? Thats goes for ALL manufactures.

And i also believe they are capable of more! lol
Look at what tuners do to the HP/TQ. All it takes is GM/FORD/DODGE a little ecm flash and have more power!

Both Ford and chevy are producing big numbers..hopefully they will be reliable too!
I'm sure every Chevy or Ford person will agree...we would rather sacrifice a little HP/TQ for a more reliable motor. But if you can do both..bring it on! lol

next thing, WHY can't we be more civilized on a discussion, instead of slamming one brand or the other?
DO you relize,that childish attitude will NOT win you any arguement! All it does is make you look like a ass that doesn't know anything!!
Its like He did it first, no she did! Sound like my kids!

BTW, one more thing...speaking of would be pretty cool if privacy class was available in crewcabs. LOL

Well I look forward to driving both trucks. I think Ford and GM have both done a terrific job here. I hope the Chevy gets similar fuel consumption figures to the Ford. The power/torque numbers alone don't mean as much as how responsive the engine feels, so that is still a wait and see game. But the numbers on both are very impressive. Since Ford released its numbers a couple weeks ago, it was a given GM would make sure they were going to be class leading.

JUST IN: Ford raises chevy. 400hp and 775TQ

LOL, Just kidding!

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