87 or 91 octane gas

[Miami-Dade]

If you are at 191k miles using 87 octane without any issues or knocking, then I'd say keep on using it.

@Nagloc68 I agree with this.

 

[Capybarbro]

If you want actual data on the topic AAA did a study on this a few years back using a '16 Escalade. The only car that experienced knock was the Audi A3.

Engineering Explained does a good breakdown and is worth 13 minutes of your time in my opinion.

 

[West 1]

I had a 2007 Escalade with the 6.2L and 6L80, it demanded Premium and the manual tells you to run premium, if you ran regular it did not like it. It was rated 403 HP I think. My current 2008 Yukon is a Denali, also with the 6.2L and 6L80. The Denali is rated at 380 HP, same engine but different tune GM manual says you can run it on 87 octane but it may run stronger on 91 octane. It runs just fine on 87 even when towing. MPG seems the same as the Escalade. I do not race them so power seems the same to me.
Never have had any knock issues detected.

It did heat up towing last weekend, trailer weighed 6500 pounds, towing in 100* heat going up long steep grade it started to get hot. Could there have been minor detonation helping it get hot??? Good question, I detected no pinging but my ears are not the best. No check engine lights at all. If I detect any knock from detonation I will upgrade to 91, till then it likes 87 just fine.

 

[swathdiver]

We haven't towed or anything else heavy - mostly hauling the four kids. Now its mine I mostly highway driving. Chicago suburbs area, Premium is about $1+ per gallon over 87. I fill up at Costco and save about 25-35c over local stations (used to be 50c). Costco doesn't have E85 at my location. I will check the price of E85 and maybe experiment a little. Thanks again.

Why buy one of the most luxurious and expensive and powerful vehicles on the planet and then fret over the choice of fuel?

You folks must drive it pretty easy because we routinely see broken pistons and piston rings after about 100K miles where the engine had been fed a steady diet of low octane fuel. You are the exception to the rule and I think that may be because of your locale.

I'm the opposite, I want maximum performance and range from my vehicles and run 93 even in my chainsaw and generators and lawn mowers.