All oil used in engines and transmissions are petroleum products. Synthetic oil is petroleum product that is refined to have more consistant molecular sizing to make it more slippery (think ball bearings-regular petroleum has different sized ball bearings, synthetic are all the same sized-hence it is more slippery). Good Luck, TomChttp://en.wikipedia.org/wiki/Synthetic_oil
Syn can be made from Petro, nat gas and a host of other substances. Like WIKI says: syn required for jet engine lubes but not for recip. We have AF&P mechs on here that should be able to comment. The Germans used syn oils and fuels in WWII and they had no Petro supply to use as feed stock....probably used natural gas.
We used syn in our 2 stroke desert bikes when it first came to our attention in the early 70's. Klotz was a favorite. It smelled like moth balls and was mixed at 50 to 1 unlike the plug fouling EXXON's 20 to 1 crap. The Klotz actually CLEANED our plugs and combustion chamber of all varnish and carbon. We eventually emptied our tool boxes of all the old fouled plugs and cleaned them by installing them in a warmed engine and running that "old" plug for the rest of the day. Result was a cleaned and fully functioning plug. Incredible stuff. Made in LA, Commie Fornia back in The Day.