This kind of game already exists since 1997 know as Krush Kill 'n' Destroy (by Melbourne House) except units do not smoke from exhaust.
KKnD is currently the closest to your idea, AFAIK.
Oil is used also in Warzone 2100 which is nowadays free and open source known as "Warzone 2100 project".
Reffineries are not used however in WZ.