AeroShell Oils W80, W100 and W120 are ashless dispersant oils specifically developed for aviation piston engines. They combine non-metallic additives with selected high viscosity index base oils to give exceptional stability, dispersancy and anti-foaming performance. No general rule exists for every engine type when choosing the correct grade of oil; however, based on the average ambient outside temperature at engine start-up the most common grades are SAE 40, SAE 50 and SAE 60, which equates to AeroShell Oil W80, W100 and W120 respectively.  Traditionally, the choice is associated with climatic zones - AeroShell W80 for cold climate regions (-17 - 21°C), AeroShell Oil W100 for temperate regions (15 - 30°C) and AeroShell Oil W120 for warmer climates (above 26°C). AeroShell Oils W65, W80, W100 and W120 are produced to meet fully the SAE specification J-1899 (Grades SAE 30, 40, 50 and 60 respectively). Furthermore, they all have military qualification approval and are listed on the Qualified Products List (QPL) issued by the US Navy and on the Technically Acceptable Products List (TAPL) issued by the UK Ministry of Defence. The blending plants employed to manufacture these oils also hold the approval of the specification authorities and this ensures that the high quality standard is always maintained.