The cost of buying oil in bulk from unknown sources

Buying oil from a bulk oil change facility where you are not sure of the honesty of the personnel might be the most expensive decision you make. I have personally seen people pump cheap oils into high quality drums to cheat the public.

Here a sample of oil I purchased from an oil change facility in Bolivia. It was an original drum of a decent brand, sold as a SAE 40.

You can see from the analysis that it is not a SAE 40. The viscosity puts it in a SAE 50 range. It has a residue of 2 ppm of magnesium and 4 of calcium that they did not eliminate from the old oils they filtered. It also has 1 ppm of dirt and 1 ppm of iron.

This oil does not protect the engine. It forms sludge, evaporates, and causes high wear that results in an engine rebuild.