The Amsoil Outboard 100:1 Pre-Mix Synthetic 2-cylinder oil is a high-quality lubricant, which was specially developed for use in water-cooled outboard engines on boats and ships. Special attention has been paid to avoiding deposits of paint and carbon inside the engine during operation. Due to the mixing ratio of 1:100 the Amsoil Outboard 100:1 Pre-Mix has a lower odour and smoke than other oils with a mixing ratio of 50:1.