Mobil Cylinder oils are high performance high viscosity oils designed for use in enclosed worm gears operating at moderate to high speeds and temperatures, and where heavy loads, slow speeds or high temperatures demand high viscosity oils. They are also intended for use in steam engine cylinder applications. They are formulated from high quality base stocks that are resistant to oxidation and thermal degradation, and the build-up of harmful deposits caused by the high operating temperatures of steam cylinders. They protect against rust and corrosion and provide good film strength and excellent lubricity and they are resistant to water washout.