I agree about only using race fuel if you need to due to compression because it will hurt your performance if not required. But, I have to disagree on race fuel causing an engine to overheat. Octane slows the burn of the fuel and creates less heat. The exception may be oxygenated race fuels. As far as avgas is concerned, I have to disagree again. I have used 100ll in several applications with no negative side effects. Including a couple of turbocharged 2 strokes and an MX banshee that is run very hard weekly and was blueprinted for 104 octane. Avgas is FAA approved, planes run at all elevations from sea level to 30000 feet and last time I checked the FAA doesn't take lightly to them falling out of the air
