MR Pro6-HT Reg is our AMA SX/MX-legal unleaded fuel for motocross and supercross, engineered to generate maximum horsepower in 4-stroke applications. It conforms with AMA Pro Racing rules, and makes more power than any other AMA-legal fuel on the market! Unlike other fuels on the market, It requires minimal jetting/mapping changes and will not require radical changes in ignition timing.Pro6-HT REG offers better octane value over Pro6 and a lower RVP, which is better suited to the higher air temperatures associated with outdoor motocross.Contains MTBE.