Its SRX racing diesel. There are two types, regular and superstock. The superstock has alittle lower btu's but the burn rate is much faster for the higher rpm engines. They are coming out with a new series of fuel thats based on the rpm range that you run your engine. It just has a different burn rate. Haven't got any of it from them yet to try on the engine dyno though. I stock both types of fuel, the regular stuff is $18 a gallon and the superstock is $20 a gallon. Just pm me if you want some details.