If you’re not bound by fuel rules, this leaded fuel is the best choice for virtually any powersports application. U4.4 reg offering the biggest gain vs. cost of any performance part you can buy. The latest generation of our U4-based fuels, U4.4 Reg makes more power than pump gas across a wider range of applications than its predecessors. Designed as a direct, pour-in replacement for pump gas, it will require modest jetting changes, i.e., +2 main jets or +2 pilot jets at most. With its higher octane rating, U4.4 Reg is designed for use in stock and modified 2-stroke and 4-stroke applications. Contains MTBE.