[Nick 95 6sp]

mine is turbocharged, so I always use 93oct, 94 when it was available at the pump, and with a decent tune I can run about 18 to 20psi or so = about 500whp or so; and a reasonable generalizatin is that the higher the octane the higher boost you can run which has not much to do with a/f ratio but just the detonation resistance of the fuel. So if I want to run max efficient boost on my turbo, 28psi'ish, I use C16 = about 630whp or so. All pump gasolines I know of have detergents in them to keep lacquer and bad stuff from depositing.

Re near to Chester County for high test ...there are probably others too, but the nearest ones I use are at Rt 202 & Rt 1 the Sunoco station has a "racegas" pump which is GT100 and I think that's about 100oct. Up on Rt 3 West Chester Pike, between where Rt 320 and Rt 476 intersect, you'll find K&G Speed Shop and they have almost every kind of racegas available, or at least a wide range selection, everything from VP105 unleaded 105oct, up to C16 which I think is 116 oct; even more radical if they might have VP Import more stable at high boost over 30psi than C16; of course they have methanol and nitromethane too for you hardcore speed freaks.