When you start your Rotax Aircraft engine, you need to know your equipment has the best fluid available running in its veins. Each spin of the prop is too important to trust it to sub-par fluids. XPS Full Synthetic 5W-50 Aviation Engine Oil was designed specifically for Rotax Aircraft engines for the best performance, reliability and safety. Over two-years’ worth of development, forty tested variations of fluids, 20,000+ gallons of aviation fuel and 12+ fired engine tests led to the final formulation. We spent that time and effort to ensure you don’t have to worry about the durability and reliability needed from the correct engine oil.