I can only tell you here in TX with 10.5:1 old school iron heads and a decent hydro roller, it takes 50/50 mix of 91/VP110 to keep the plugs clean. Above 11 (old dragster motor was 11.5) I'd run straight 110. That's 9.50/gallon at the track or about $7.80/gallon in a 54 gallon drum. Last year anyway, probably more this year. Why I switched to methanol at $200/drum. The new motor is 12.5:1, marginal for 110 so next up is like 14.72/gallon for C12 (VP web site list price) if I want to run gas. Pass.