well i've been doing the acetone thing for the last 7 fill-ups and i found 1 oz to 10 gal works best for me.
i have a completely stock engine with 130K on it, 2.73 gears, T5, and 225's at 38 psi. on this last tank i drove 310.8 miles, 289.2 highway at around 70mph, so pretty much all highway...