Gas help

[tyv193]

I know there has probably been a thread about this already but I am going to ask again. With a completely stock 2002 Gtp what is the lowest octane you can go without engine knock. Is it ok to use 89 or 91 instead of 93? I wont use 87. I don't want to have to worry about not getting into the boost. Can someone give me some insight on this?

[matt5112]

91 or higher. Depends on your car.

You basically need to scan to be sure, but 91 octane should be fine, i'd run 93 for the insurance unless i had the ability to scan.

[tyv193]

Ok, Ill not that much difference in price between 91 and 93 anyways. Just wondering for the long run if i could run 91.

[matt5112]

I'd run 93 to be safe then.

[tyv193]

ok, thanks.