[lmacmil]

I have always run a whole season on my lawn mower oil and changed it after the last cutting. The oil was always pretty dirty so this summer I changed it in August. I was going to change it again last week but it looked pretty clean on the dipstick and on my finger. I probably cut the lawn 10 times since the oil was changed.

Should I change it even though it looks clean? I know there must be some contaminants in it but nothing like it would have been had I not changed it a couple months ago.