Race fuel

[puckles]

The primary benefit of race gas is knock resistance. This in turn allows the engine to run a higher compression ratio which increases it's thermal efficiency. More advanced ignition timing is also possible. Additionally, race gas is a more consistent product as mentioned above and also includes other additives that help lubricate the fuel system etc.

Basically, race gas is a variable that can help a bleeding edge tune in the same way that stiffer valve springs or intake porting can help. In fact, higher octane race fuel actually has a lower energy density than pump gas. It is the increase in thermal efficiency of the otto cycle that allows the engine to make more power when tuned appropriately.

[jtiisto]

Originally Posted by puckles

The primary benefit of race gas is knock resistance.... higher octane race fuel

There's high octane pump gas that provides all those benefits. Going to specialized race gas has additional benefits, mostly through oxygenation.

You are spot on for primary benefit of high octane gas. However, going from high octane pump gas to actual race gas as other benefits.