Mobil 1 Racing 4T 10W-40 is recommended for 4-cycle motorcycles which specify the use a 10W-40 engine oil. This oil will help provide excellent performance in motorcycle engines that are designed with a common engine/transmission lubrication system or where the engine lubrication system is separate from the transmission system. In the case of the latter, follow the manufacturer^s recommendation for the type of fluid to be used in the transmission. Mobil 1 Racing 4T 10W-40 engine oil is designed to help provide the proper frictional characteristics necessary for wet-clutch common engine/transmission systems. It has been fully tested, both on laboratory dynamometers and in the field, to help provide optimum horsepower and acceleration. Maximum shear stability to help resist viscosity shear down in high performance engines and transmissions Exceptional thermal stability to help resist oxidation and high-temperature degradation Outstanding protection against wear of engine and transmission components Enhanced lubrication to help maintain maximum power and acceleration over the life of the engine Optimized wet-clutch performance Excellent low temperature flow characteristics to help minimize engine wear during start-up