What octane gas?

[Dnt]

The noise is hard to describe but is more of a Click (actually sounds like a loud lifter click) rather than a knock or ping that you would expect with detonation. I thought at first that it was the flapper valve in the exhaust clicking so I clamped it open just to be sure. Still there. Could be an issue with a lifter? just inconsistent and hard to make it do it. i have no way to verify the spark retard settings. Only live data monitor that I have is a INNOVA 3160 and I cannot see anything in the live data screens or in the paperwork that indicates a spark retard readout.............

[Skidsareforkids]

I'm skeptical that the 6.2 runs high enough compression to warrant higher octane fuel... My wife has 52,500 on her '16 Denali XL and every drip of fuel (2500ish gallons I think) has been 87 octane. I've got 2,500 on my 17 Denali 1500 with the same motor, and have experimented with both 91 and 87 and notice no difference whatsoever...

 

 

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[wingsaa]

I run Top Tier 93 in my XL Denali 6.2L.

[markitzero]

It's very important to use the recommended minimum octane in the engine, even today's modern engines with knock sensors. The 5.3L only needs 87 octane but the 6.2L needs 91 octane minimum.

 

And I would argue that the 5.3 does better at 91. I had a rough idle, found another post about using a bottle of techron and a tank of 91 and the result was a nice smooth idle. I almost feel as if Chevy says "it will work on 87 just fine" knowing that most people won't complain. All I know is that after the bottle of techron and 91 it idled smooth as silk.

[MSgtNix]

At 89 octane I get about 17.5 MPG. When using 93 Octane I get around 20 MPG. Paying for the no alcohol gas has given me 19 MPG. Wondering which is best for my 5.3 L Suburban.