Whats so special about Onan generator oil
Just doing a service on my generator (5500 Marquis model 5.5HGJAB-1038D). Bought plugs and filter, but they wanted $15 a quart for the Onan SAE 15W-40. Thought maybe I could just get it cheaper at an ...
Forum Discussion
A few years ago with my class C 4kw generator, I called the local Onan service center and asked if Shell Rotella 15w-40 was ok to use. They said yes, every bit as good as Onan branded oil. Now I use it in my class A 5.5kw generator.
