AMSOIL 20-50 V-TWIN Motorcycle Oil surpassed Harley Davidson SYN3 motorcycle oil 6X better for much superior protection in independent lab tests. Especially loss of viscosity, compensator wear and transmission wear. With AMSOIL 20-50 there was no “ticking” or “thunking” noise when tested. Harley Engines ran cooler and shifted smoother with Amsoil. This article discusses the differences between Harley Davidson Oil, Amsoil and how they perform.