Alright so I picked up this 250r that was built for race fuel. The guy was running C-12 in it which as you all know is ridiculous right now at $11 a gallon and only in drums most places. My question is would it be horrible to step down to VP110 which is $7 a gallon? I don't care if one performs just a little better I just bought this thing as a backup ride and don't want to grenade the engine.

110 is fine

110 AND YOUR GOOD TO GO

Sweet!!

110 is what mine run on

It all depends on compression and to a lesser degree, squish band and porting. If 112 is what the builder specified, hard to say what 110 will do. Can you get ahold of the builder or prior owner and find out what in the heck was done to that engine?

see thats what sucks about vp racing fuels, go to their site and look it up, alot of their fuels are lower octane ratings then vp110, they just package it as something "new", look at the motor octane rating, research octane is not what your motor is actually getting, that is just a anomaly in the solution of the "race fuel equation"

X2. I would run a compression check on it to see if it is even in the race gas territory. Both fuels are close in octane (C-12 at 108 and VP110 at 107) but for some reason C12 is a little "cleaner" fuel then VP110 has been in the past, and the C12/C14 is a far better fuel for heat soak for some reason when used with iron cylinders.