I was thinking the banks system is there anything else I can add to the truck to get better MPG? First diesel I've ever owned I used my 91 f-350 to haul but used way to much gas so I got my 1998 dodge 5.9 12 valve diesel to save money now I want to get as much mpg as I can. Any advice would be greatly appreciated.

 

wont help at all

 

In my opinion gearing and reduction of friction Will make the most difference. If you have 4.10 gears you will get **** mileage trying to do 70. Gear vendor is an option but it's expensive. If I were you I'd get some short gears and make sure all your rolling components are fresh. Good wheelbearings and brakes, you could also consider getting a set of 19.5 rims and running around 100 psi. Drive like grandpa and try to keep it around 1700 RPM on the highway