Brian76

Can somebody please teel me what exacly is a 91 tune,or 93 tune, or even 89 tune. I know its the octane but does it mean if you have a 91 tune you cant use 93 or you cant use 89. or if you have a 93 tune you cant go below that I know its something like this but I would like to know exacly.

GidyupGo

it just means you have to use that grade of octane gas ..............or higher.

sailing220

You can only use gas that has an octane rating matching your tune or higher. For example:

If you have a 89 tune, you can use 91 or 93 or even 104 octane gas, but you can't use 87 octane gas.