Quote Originally Posted by Jolly Roger VX'er View Post
I'm coming up on 40k miles of being supercharged (VX is about to have 80k) and like you always ran premium in it since that is what Alpine reccommends.

Tone told us early on that he used to run regular basically all week when doing basic commuting with the VX; and filling with premium before doing any rallycross or other "demanding" duties.

If you think you're going to run your VX hard for any length of time...I'd still run premium though just to be safe! That's my $.02
This is what I've been doing since the price of petrol has moved closer to $4.00 gal.
Regular for daily back & forth to work etc., premium or mid grade w/ 10% ethanol for a treat on weekends or for wheelin' trips etc.
I never see a CEL unless we're at a higher altitude, & IMO, regular is plenty good for interstate trips across the flatlands.

I've also experimented with "octane boosters" (Amsoil) with no effect on mpg or performance.