bounder39zman wrote:
Previous posts have good advice, and correctly stating NO oil filter.
This is a splash lubed, 3600 rpm engine so keeping oil clean, full on dipstick is critical. I recommend 15W-40 such as Shell Rotella or Mobil Delvac (or any good brand) as preferred lube. This is what ONAN puts in at factory. Synthetic certainly wont hurt, but wait until engine is "broken in" before using synthetic oil. Oil is cheap compared to a replacement engine, so change it often. Recommend annually, or 100hrs max.
Chevron Delo 400 15W-40 also matches the same specs. I generally use any one of those 3 in my Onan 4KW gas genny. Yes, which ever one is on sale in the 4 qt jug is usually the best deal. They all meet Onans specs. They are "technically" synthetic oils without the synthetic oil price.
Chum lee
