As for fuel in a race car. Be sure to read your spark plugs at regular intervals as well as your oil level. Aviation fuel is a "slow burn" formula designed to burn with less oxygen at the upper altitudes. It also has a blue dye in it which can cause havoc with idle jets being that the dye can leave a white powdery substance that can restrict an orifice size. Aviation fuel is also a cleaner fuel and tends to strip oil (and sludge) from metal so checking the oil level should be mandatory. Lastly, several small bore engines run fine with it, while others may not. Large bore engines are up for grabs. Each is an individual case. Aviation fuel does not work well in my Chevy V8, or my Harley's. It does work well in the street sweeper, high pressure washer, forklift, etc. etc. I see a lot of formula racers using it. Fuel injected engines/racers generally have to retune to use it.