I am, sidewinder 30%; runs very well. I've had it about a month, and have about a gallon through it. It likes the 30%, makes great power, fuel economy, and tunes up pretty easily. The only thing I didn't like is the stock head is so small, and doesn't stick up above the body on my eight. I just upgraded to a larger King Headz heat sink, gonna begin testing either this afternoon, or tomorow.