What is the 23hp difference between the Denali/Escalade?

[quikag]

I haven't been able to identify the differences in the two 6.2L motors to provide 403hp in the Escalade and 380hp in the '07/'08 Denali. Anyone know definitively?

 

[Black Dog]

It's mostly higher compression ratio, and maybe a few complimentary tuning adjustments. But more compression makes more power.

 

[Black Dog]

They feel that a Cadillac owner should get a little something extra and changing the CR is easy to do just by altering the piston profile so I doubt if there is any real difference in the heads themselves toward altering it.

 

[quikag]

So the Escalade has different pistons that increase the CR. That, plus a few tuning tweaks gives it the extra 23hp? I find it interesting that they give the Sierra Denali 400hp, but only gave the Yukon Denali 380hp. For '09 the Yukon Denali is supposed to have the full 403hp.

Oh well, guess I'm stuck with my measly 380hp. I really thought it was just marketing hype that rated the 403 vs. 380 and rwhp was basically identical. I guess not.

 

[ibobby]

doesn't the Caddy weight a little more?

You also have to look at torque when talking horse power and speed.

 

[Vrrooom]

It could also just be under-rated... GM likes to do that. Especially since they have to put their flagship model on the pedestal. A GMC the same as a Cadillac? Impossible.

 

[quikag]

Oh, I have a 2WD Yukon Denali and it's plenty fast for a daily driver truck. If I need speed I have my 480hp C6. That said, I thought it was odd that there is a true 23hp difference between the Slade and Yukon Denali. I thought it was just BS marketing and the power output was identical in reality.

It seems like a lot of work to have different pistons for the Yukon Denali and then use 'special' pistons for the Sierra Denali and Escalade.

 

[Grounded]

I was told that the engine's are one in the same. Just different tunes.....

 

[quikag]

I was told that the engine's are one in the same. Just different tunes.....

That would make a lot more sense than use different engine internals...I was searching on google for an SAE tech article to explain the differences, but I could never find one on the 6.2L truck motors.

 

[Black Dog]

Whatever, but pretty sure I'm right...

Such as, there are 2 different 6.0L motors from a couple of years back, the LQ4 and LQ9, I think. The LQ4 has dished pistons, 9.4:1 Compression Ratio, and 300 HP. The LQ9 has flat-top pistons, 10:1 CR, and 345 HP. Maybe the rods are beefier or something but that's the jist of it. So this is GM's modus operandi.

I don't make this kind of stuff up anymore than GM would just take 2 identical motors and then give them each a different tune. Not without at least a different camshaft, etc. They don't usually just push the envelope like that; rather they try to optimize a set of parts with a set of criteria.

The muscle cars of the '60s just disappeared to weak-as-can-be smog motors in 1974. Why did they lose power? It wasn't the smog equipment, there were smaller carbs, but it was all about lowered compression ratio. Engines went from like 10.5:1 down to like 8:1, albeit gradually from 71-74.

While a timing advancing tune may require higher octane too, it is the case with the Caddy engines that they need higher octane because of the higher compression ratio. More compression= more heat= quicker pre-ignition.

Any more questions?

 

[Black Dog]

And the torque in each 6.2L is virtually the same, maybe even a couple points less in the higher HP version.

 

[quikag]

Black Dog, I'm not disputing what you're saying, I'm just surprised they use different pistons and tune to de-rate a motor. You're right in the LQ4 and LQ9, so it's definitely their M.O. Both the Denali and the Escalade recommend premium fuel.

Thanks again for all the info!!

 

[Stargazer]

My Denali recommends regular 87 octane.

 

[quikag]

My Denali recommends regular 87 octane.

That's odd because the inside of my fuel door cover says premium fuel recommended.

 

[Stargazer]

That is strange. I just checked my fuel filler door and I have no stickers or information anywhere there. Page 423 of my Denali Owner's manual just says to use 87 or higher.

I wonder if it's a difference between '07 and '08?

 

[GMCYukonDenali]

I have an 07 Denali that was assembled in Wisconsin and a friend has an 07 Denali that was assembled in Texas. My gas tank door has a sticker that indicates premium only, his does not. I am guessing those without the sticker will find that their Denali was assembled in Texas.

Checking my owner’s manual it says 87. I contacted GM about it. Comically, GM contacted my local dealer and asked them (yes, they actually told me in their response that my local service manager recommended premium).

http://media.gm.com/us/gmc/en/product_services/r_cars/r_c_yukon_denali/07index.html indicates that premium is recommended, but not required (for 07s and 08s). Also, the compression ratios for the 07 and 08 are identical: 10.5:1. I asked my regional rep why the Escalade was 403 HP, he indicated air intake and tuning.

On another note, I also asked about the difference between the driver’s side mirror and the passenger’s side mirror (one has an extra bead around the glass)—he said the difference was due to crash testing. Take it for what it’s worth.

 

[Black Dog]

Ask anyone around the dealership a question, and then just assume that some opposite answer is the right one. Amazes me some of the lameness they speak.

 

[SAUDILTZTAHOE]

Here in saudi the Denali and the Escalade are rated at 441HP and 454 lb-ft.
Escalade
http://www.cadillacarabia.com/content_data/LAAM/ME/en/GBPME/cadillac/Escalade/esc_specification.html

Denali
http://www.gmcarabia.com/content_data/LAAM/ME/en/GBPME/012/G1/4Y/4Y_features.html?cntryCd=SA

 

[ibobby]

Mine says premium also.(inside the fuel door)

 

[Stargazer]

My Denali was made in Texas, so no sticker.