Fytch,

A mixture of castor, nitromethane, and alcohol is used for glow fuel. A mixture of castor, ether, and kerosene is usually used for diesel fuel.

There are other aditives such as amyl nitrate, amyl nitrite and a few other things are used to make diesel fuel burn better.

When most refer to synthetic oils, they are usually referring to using synthetic in place of castor, or mixed with castor as the lubricant.

George