OEM Tractor Oil vs Shell, Valvoline, Amsoil, etc.

rScotty · Dec 19, 2024

I'm sure that oils today are better than they once were. But after a lifetime as a mechanic, I'm realizing I have never seen a failure I could say for sure was poor quality or old oil - just as long as the filters were still working and the oil not too contaminated with fuel or water.

I have seen milky trans/hydraulic oil contaminated with water causing rusted pumps, gears, and bearings..... And I've seen incompatible greases ruin O rings and seals and wheel bearings. But I've not seen internal engine/tranny wear if the oil was anywhere close to good... no matter how old.

Some of the oil I've encountered doing repairs was old enough to have formed gum in the sump pan - particularly back in the days of non-detergent oils.

I wonder how much of our oil lore is just advertising hype that we have come to accept as fact?

rScotty

ning · Jan 6, 2025

rScotty said:
I'm sure that oils today are better than they once were. But after a lifetime as a mechanic, I'm realizing I have never seen a failure I could say for sure was poor quality or old oil - just as long as the filters were still working and the oil not too contaminated with fuel or water.

I have seen milky trans/hydraulic oil contaminated with water causing rusted pumps, gears, and bearings..... And I've seen incompatible greases ruin O rings and seals and wheel bearings. But I've not seen internal engine/tranny wear if the oil was anywhere close to good... no matter how old.

Some of the oil I've encountered doing repairs was old enough to have formed gum in the sump pan - particularly back in the days of non-detergent oils.

I wonder how much of our oil lore is just advertising hype that we have come to accept as fact?

rScotty

There are definitely some brand of oil or oil-adjacent products that are zealously accepted as fact by their adherents...