what exactly is motor oil made from ?

Answer 1

Motor oil is refined from crude oil. There are synthetic motor oils made from animal and vegetable products, but they are only a tiny part of the available products.

For more information, try an internet search on "petroleum products."

Answer 2

Most oils today with API rating of SM are okay. The last I heard Amsoil does not have the SM rating because it contains ZDDP (first source), which is severely restricted in the SM spec (second source). The phosphorus content of ZDDP is considered a threat to the catalytic converter, which is why recent API specs have clamped down on it. That said, I stay completely away from Havoline (not to be confused with Valvoline, which has a good reputation). Havoline oils used to have a reputation for producing hard sludge deposits even in engines that received regular changes. Quaker State has also been accused of the same problem but I find the claims dubious. Beyond that we are getting into the "religious war" realm. I switched to full synthetic oil about a decade ago after battling deposits in the intake of a turbo Volvo. The Volvo gurus reported those deposits, left behind by the engine re-breathing so much crankcase vapor the intake is perpetually covered in oil, do not appear with synthetic oil. Since then I have noticed that engines regularly run on synthetic oil look brand new (no varnish) under the valve cover - see the third source for pictures. I use Mobil 1 but don't claim it is the best, just good enough for me.

Answer 3

It is one of the fractions that can be distilled from crude oil by heating it and collecting the parts that come out at different temperatures.

Answer 4

Petroleum