An excellent 4 cycle kart oil for engines running methanol. Very slick oil. Do not use until your engine is broken-in. Recommended by ARC because it performs exactly as a racing oil should. ZERO carbon, minimal wear, great corrosion protection, proper film strength and the durability to provide those features for the entire race. ARC's interest in oil is based on their goal to eliminate oil related connecting rod failures. Thor filled the bill. No matter what you are told or what you read, there is no oil better than THOR. Believe it