I own a 4hp Snapper push mower my Grandpa gave me before he died. I think it is about 10 years old. Personally I run 10w30 semi-synthetic oil in it. Some people recommend stait 30 wait oil because of some of the close tolerances in engines. I like a good 10w30 oil because it doesn't flow like water. I really do not recommend using full synthetic in a old engine because it will gell any rubber seals. Sears normally keeps a good supply of oil just for lawn mowers. My favorite is semi-synthetic because it keeps things cooler & quieter. Whatever is in ones budget.
Patric, June 2004
