The New Aviation Multiviscosity Oil, SAE 20W-50 for General Aviation 810573

For the past two decades, since the introduction of the ashless dispersant aviation oils, the quality of these oils has remained relatively constant. These “single grade” aviation oils, however, required changing as the weather changed whether the usual 50 hours of service has been accumulated or not. In fact, there have been frequent reports of aircraft engines being ruined because heavy SAE 50 (Commercial Grade 100) oils were in the crankcase when they were started and operated in cold weather without engine pre-heat. Present modern aircraft can easily fly from a cold area, with a light SAE 30 (Commercial Grade 65) oil in the crankcase, to a hot area and experience high wear due to boundary lubrication conditions and high oil consumption.

With the development of shear stable, heat resistant viscosity index improvers such as butadiene-styrene co-polymers, an excellent new generation SAE 20W-50 general aircraft oil which meets the requirements of Avco-Lycoming Specification 301F and Teledyne Continental Specification MHS-24B, is now being used commercially.

Over two years of successful field service from the Artie to the tropics has proved the concept of the multigrade general aviation oil, SAE 20W-50.