Hello, i have a 1993 dodge w150 with a 318 and a 4 speed auto transmission, engine is stock appart from a small cam and arp head stud, juste wondering if you guys have any idea why the truck has horrible fuel mileage, like 50 miles with half a tank, truck runs great and dont seem to have any vacuum leaks, only mechanical problem is the oil pressure drops when the engine is at low rpm

 

Pull some spark plugs, see what they look like. (post pics, if you can.)

 

Search all along your fuel lines and your tank for a leak.