I've read many times over the years about higher compression engines requiring higher octane fuel than pump gas has to offer so I was wondering, is there a specific level of compression that requires a jump from pump gas to some sort of higher octane gas or race fuel? Or, are there other factors of the engine build that would have a bearing on how much octane is needed?
A good rule of thumb is that 12:1 or higher should be using race gas. You may or may not be able to break that rule depending on how many tricks you pull but the average bracket guy with a carb with 12:1 should be running something like C12 or VP101.
