I bought lower gear unit oil from an auto parts store with the same viscosity numbers as the lube you'd find at a marine supply store. The salesman at the store said it would be fine for my engine (1985 140hp Rude VRO)<br />I bought it because I was already in an auto store, didn't have any marine grade oil at home and I needed to drain and winterize the engine, and I was told it is a "no,no" to leave the lower unit empty during the winter. <br />Just double checking, because I've heard that the lube needs to have certain additives (for water leakage,etc.), and that I should really get the stuff they sell in the marine store.
