In Reply to: Re: gear lube / motor oil viscocity difference? posted by Rich L on 05/30/02 at 11:23 AM:
I may have misinterpreted your question a bit. If someone tells you that gear oil and motor oil are the same thing, that would be wrong, in general. They are only the same in that they each are lubricants and probably of petroleum base. That's all. They are not interchangeable in the sense that "motor oil is gear oil with less viscosity." No. If you smell gear oil, it's putrid!! The sulphur is odiferously obnoxious to sniff and just as toxic. Motor oil smells kind of good. I believe that the sulphur content has its function in providing lubrication as a function of heat friction. Viscosity in and of itself, (I believe is measure of flow rate in a standard way and holds its truth across the board, given any oil measured.) Ketchup and honey might be another matter. If you are considering gear oil as a substitute for motor oil, I can't say that it would work. Their properties would be different but I don't know all of how.
I don't necessarily recommend it but in a pinch, I have thrown in 8oz. of gear oil into my motor oil to undo the effects of gasoline wastes thinning the oil and also to top it off. I even daresay I noticed an improvement in acceleration after that. A regular oil change could have produced the same perhaps. Maybe this answers your question better.