I stumbled upon this old article dating from 1945 which looks very much like an Allied post-war assessment of the synthetic base oil technology the Germans used during WWII... http://www.fischer-tropsch.org/primary_d..._lubricants.htm If like me, you're a chemical engineer who's dabbled in lubricant formulation, this is fascinating stuff. Lacking sufficient supplies of crude oil, the Germans took something they had lots of, namely ethane, and steam reformed it into ethylene. After a complex purification process, the ethylene was polymerised in the presence of Aluminium Chloride catalyst to what looks to me like a crude form of heavy Poly Alpha Olefin (PAO) base oil. The plant could be operated to make a very heavy base oil (SS.906) with a minimum KV100 of 43 centistokes or a lighter base oil (SS.903) with a maximum KV100 of about 21 cst (so roughly in SAE 50 territory). One of the things that made me smile was that even way back then, the Germans were using the 250C Noack volatility test as a quality control test! It looks like this synthetic base oil was blended with other stuff derived from crude oil. Very little seems to have been added to the base oil by way of additive (no ZDDP for example) before it being shipped out for use. The article also shows how the Germans were making Di-ester base oils with excellent low temperature qualities from Adipic Acid. The tech is very clever in that the di-ester base oil is put together from various derivatives of cyclohexane. Finally, the Germans seem to have used a complex tin-based additive to minimise ring stick on their aero-engines. I have never come across anything quite like this before. If there are any chemists out there, what is this stuff and more importantly, is it something we should be rediscovering today?