Which gas for the 6.2L

[stevek]

Seriously, you'll buy a 60k Denali just to save a few bucks at the pump every week?

 

[Fast55]

My Tahoe didn't care for even mid grade or 89 Octane when stock. I never even tried regular. With tuning, 91 is the minimum. The owner's manual says:

Use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle’s
acceleration could be slightly reduced, and you might
notice a slight audible knocking noise, commonly referred​

to as spark knock.

The way I read this is that they "recommend" 91 or higher octane and you're using something else at your own risk. If you admit to having used anything other than 91 and you have engine damage attributed to detonation, you will be screwed I'll bet. It even has a label "recommending" 91 inside the gas tank door.

 

[07Denali]

I just got out of a Lexus LX570 so putting premium fuel in is the norm for me, this one even gets better fuel economy! But again we were told by the dealer to use 87. I agree that a few extra $ a tank is not worth long term issues, but when dealers tell people who lease a car that 87 is what to use, that is an issue. Especially seeing as the manual and under the gas cap say premium. We are probably the exception that do all of the required service on a leased car.

 

[stevek]

Let me just point out to you, the dealer telling you to use 87 is also the dealer you'll probably be taking it to when you're having problems... it's in their best interest for you to screw up your car

 

[07Denali]

Maybe it is. If they are going to cover it under warranty and I am never going to own it outside of the warranty one COULD say, so what? Not that I would, but one could. Don't know about GM, but with most other "luxury" makes they check on warranty claims very carefully and charge the dealer back accordingly. All I know is that all I did was ask my wife what she wanted to drive, what color and called a friend that owns a gmc dealer and showed up and signed the lease. Our new one has 1500 miles on it and just found out that it has had 87 in it since she picked it up. And she specifically asked about what grade of fuel to use. I personally think that domestic car people and dealers are so used to just using 87 octane gas that they are not "sold" on spending the extra $ for premium. We have spent the last several years in Lexus so we are "programmed" to use premium anyhow. Especially since my wife shops for groceries at Kroger and gets 20 cents a gallon off of gas, all the same to her.

 

[totheyard]

2.50 more per fillup or 2,500 in repairs ? mmm Yeah ...

Why would we pay out of pocket, when the the books states 87 is ok? Its more then $2.50 too! I could buy a lot of King Cobra with the savings!

 

[yooks11]

Seriously, you'll buy a 60k Denali just to save a few bucks at the pump every week?

Agreed. I fill 93 as well.

 

[stevek]

Don't know about GM, but with most other "luxury" makes they check on warranty claims very carefully and charge the dealer back accordingly

You got lost on the way to the dealer, they are very far from "luxury."

GM is out to nickle and dime. The dealer can say "oh it's due to using low grade fuel" so that GM or the dealer doesn't have to foot the bill, it'll be on you... also voiding your warranty on the motor and any fuel tank/pump/line problems. They find any way to screw you

 

[totheyard]

I have emailed 3 dealers and GMC themselves. Asking them to clear up the octane confusion in their manual. Nobody will answer the question via email. They want to talk to me on the phone. I want it in writing. I guess 91 it is!

 

[THE YETI]

I have emailed 3 dealers and GMC themselves. Asking them to clear up the octane confusion in their manual. Nobody will answer the question via email. They want to talk to me on the phone. I want it in writing. I guess 91 it is!

It is in writing on the inside of your gas door.