Lubricants

Piston Engine Oil Products

There are a variety of choices of piston engine oil available now that BP has entered the market with its Castrol Aviator line of oils. And each company's marketing material claims that its oil is superior to the others. Most of the oil manufacturers market heavily toward their end-user customers, and that is primarily the pilots and airplane owners. Of secondary marketing interest are the shop owners and managers who are often asked for advice on which type of oil is best.

So what do you tell your customer when your expertise is drawn upon? Do you defer to the oil company marketing hype or do you have some special knowledge that makes a particular oil your favorite?

In an effort to clarify some of the differences, we offer this chart showing the major aviation oil brands and some of their differences. Only a chemist with a deep background in lubricant research really knows what is unique about each of these oils' makeup and additive packages, but some basic information should help when dealing with customer questions.

Many manufacturers now include an anti-scuffing additive that meets the requirements of Lycoming AD80-04-03, saving owners the additional cost of having to pay for the expensive Lycoming LW-16702 additive on top of oil (about $20).

Note that while most of the companies make oils designed for engine break-in, there is little evidence that basic mineral oils are necessary for break-in, as long as an oil that is not synthetic is used. The anti-wear additive packages are mixed with base mineral oils, and it is the mineral oil itself that is responsible for primary lubrication. One caveat, however: if the overhauler recommends using non-ashless dispersant mineral oil for break-in, then not doing so may affect the engine's warranty.