Evaluation of Multi-Viscosity Oils Designed for Aircraft Reciprocating Engines

Six, one hundred eighty brake horsepower aircraft reciprocating piston engines have been operated for one year using three different multi-viscosity oils. Two of the oils were semi-synthetic blends and the third was an ashless dispersant. These three oils were compared with six (6) identical aircraft using a single grade aviation oil. Preliminary results have indicated that the engines utilizing multi-viscosity oils exhibited improved cold-weather starting characteristics, averaged lower oil consumption, and displayed similar wear rates when compared to the six control aircraft using straight-weight oil.