[Gary]

I was considering buying a 2021 Tahoe High Country which comes std. with the 6.2L V8 engine, until I discovered that GM recommends 93 octane. I live in California and they don't sell 93 octane here. Premium gas here is 91 octane.

My question is, can I burn 91 octane in this engine without any ill effects like damage to the engine or reduced engine life ? I do not plan on towing. Will GM void my warranty if I run 91 ?

Would I be better off downgrading to the Premier and getting the 5.3L V8 engine ?

 

[Brennen81]

I heard that in most cars the ECU will adjust for the lower octane fuel with no harm done. Only downsides should be lower performance and some decrease in gas mileage. Some folks in your position pour in a bottle of on octane booster and that may be a good alternative.

A safer route would be going to the 5.3 if 91 is all you can get.

 

[Duffy]

Accoridng to the owner's manual you use has rated as low as 87 with the 6.2L engine. But like @Brennen81 said you won't have the same performance and fuel economy.

https://my.chevrolet.com/content/dam/gmownercenter/gmna/dynamic/manuals/2021/chevrolet/tahoe-suburban/2021-chevrolet-tahoe-suburban-owners-manual.pdf