If I was you I would use the 90. I have never seen 86 before.

 

I ran 87 octane for the longest, but have been using 89 octane (midgrade) for several months. The 6.0 seems to run smoother with less knocking on midgrade. JMHO

 

Wife was going to town and told her to fill the Escalade up with 90.

 

Run the premium. Thats if you want to take advantage of the power of the 6.0. If you run regular the computer will de tune because of knocking and it will lose its pep. I have always ran premium but one day my brother borrowed the escalade and filled it up with regular upon returning it. Just ran like a dog.

 

I only use premium in my 05. Since we are all buying Escalades, we can obviously fork out the money for the better gas. It will definitly make it run better.

Thanks.

 

I have a 2004 since new and I run Mobil or Shell or Exxon regular 87 oct.
If I sense any ping at all I fill with the next grade up.

 

Thanks guys

 

Your owners manual calls for 91 octane, good luck with your new truck.

 

Highest grade as always. didnt know 86 existed.

 

The owner manual says you can use 87 ocatane, its just for performance as a sense if you are racing 1/4 mile. Spend the extra money.

 

Honestly... i have tried all grades and really noticed no difference... i would feel like s#@t putting the cheap stuff in the lade, so i use the middel 89 octane... i noticed no difference with premium, and i am going on 49k now...

 

Durring the summer is when you really need the premium. Without it, it will be knock city and a lumbering lade...

 

I run midgrade just to be on the safe side. I found NO benefit with premium except to get rid of the extra money I had laying around. I actually got better gas mileage on the cheap stuff but being a mile above sea level allows me to run a lower octane fuel.