Can 15w40 diesel oil be ok for my old atv?
15w40 Diesel oil -like Shell Rotella or Mobil 1540- is a good general use oil for most ATVs or japanese motorcycles with unitary transmissions and wet clutch’s. The diesel oil tends to have a zinc additive that later light car oils are short on(effects catalitic convertors) that is a fairly good gear lube, high pressure lube. Clutch slippage may be more related to age and 20 years of use than oil used. Point to make though is what did old Suzi call for originally- some of the old 2strokes called for ATF in transmissions- some called for the old Ford type F that let wet clutchs grip better than GM spec Dextron. Some of the follow up 4 stroke engines had the same ATF called for in their transmissions and seperate engine oil.
