What is the best grade of gas to use in a 2004 vette?

 

The more mods you have made, the higher octane you will need. Personally, I would recommend goin' into the 90's, and stay away from the 80's.

 

I use Arco and Mobile (91 octane) and have never had any problems.

 

i personally don't believe in anything lower then 91....unless it's for my lawn mower...

 

Shell V-Power all the way.

 

I have never put anything but premium (91 or 93 octane) in my vette even when stock. I understand the ECM will back off timing if it detects lower octane fuel but why make it do that and take the chance? The "premium for premium" is so small -- not sure it needs it but as I said its never been fed anything different and I never had any problems.

There is one station around here that sells 103 octane racing gas ($3 gallon above premium) and I ran one tank of that but it didn't make much difference with the stock tune.

I do know my 'vette puts out more power with higher octane gas and when re-tuned to use that octane (my shop played with it a bit) and that when running that fuel, with that tune, it can pick up a few tenths (gets into the 9s on drag radials, etc.) but since that grade is not commonly available I stick with a tune for 91 octane.

You can buy small bottles of octance enhancer at the auto store - STP and so forth sell them. One or two in a tank are worth several points of octane (I think the fine print on the bottles tell you how to calculate the gain). If you are in doubt about your tune and need for premium, you can put a couple of bottles in and see if it makes a difference. By the way, that stuff tunes the tips of your spark plugs a faint orange but seems to do no other harm.

 

Thanks!!!!