Their main function is to reduce friction between moving parts, prevent wear, and help cool and clean the engine. The correct oil ensures safe operation and a long engine life.

There are two types of additives available:

Ashless Dispersant additive indicated by the ‘W’ with Aeroshell and with the ‘AD’ or X/C with Phillips, keeps engine wear debris suspended in the oil so it can be filtered out, reducing engine deposits. Some believe it prevents enough wear so as not to work as a break-in oil, however both manufacturers express that this is not the case and provide the 100 and ‘M’ oils only because of traditional demand.

The second available additive is the Anti-Wear and Corrosion additive known as the “Lycoming Additive” or  LW-16702, that has an anti-scuffing agent. All manufacturers also include anti-corrosives with this additive package that comes with the Aeroshell ‘Plus’ and 15W50 oils and the Phillips “Victory” oils.