Another thing in respect to fuel and engines -- heli-engines tend to be run very rich so can get by with a *liberal* dose of what passes for synthetic in most fuels.

Most airplane engines however, tend to be run much leaner so that little bit of castor is *very* important -- especially with ABC/ABN engines where the fit of the piston in the bore is *much* closer and therefore the lubrication is far more critical.

I often hear people telling me that they've run CoolPower straight synthetic oil in all their engines without any problems. It often turns out however, that these folks also think 100 hours of engine life is *lots* -- whereas I tend to expect (and inevitably get) two or three times that out of my engines, possibly because I use a little castor in all my fuel.