I have purchesed a 1995 F-150, inline 300cid.w/std shift.
This truck has 74,863 Original miles and has been gargae kepts,show room new,drives,and handles as if it were just off the show room floor. All records of oil changes,(every 3,000 miles),inspections,etc.
It should be getting around 15-18 mpg.
I have just changed the oil,all filters,and it only gets 9.1 miles to the gallon at around 55-62mph. Above that speed,it gets less.
What can I do to INCREASE my performace of this truck... (it carrry nothing in the bed).
However it does have a camper shell,but does not over extend the heights of the cab or hang over the sides... Thanks... ray

1. Check engine timing with a timing light.
2. Replace oxygen sensor. A bad oxygen sensor can radically affect gas mileage, since it controls fuel injector duration.
3. Go over the whole ignition system. Replace spark plugs (Motorcraft only), spark plug wires, rotor, distributor cap. I would consider replacing the igniter and coil, if you plan on keeping the truck.
4. Replace air filter and fuel filter.
5. Check MAF sensor.
6. Check tire pressure.
7. Add Shell Regane or Chevron Techron fuel injector cleaner to your gas tank every 6 months.
8. Use 5W-30 synthetic engine oil (e.g. Mobil 1), synthetic manual transmission fluid, and synthetic differential fluid. This should increase gas mileage by 8 to 10%.
9. Check for any codes being thrown.
10. Check for dragging brakes, including emergency brake.