Does anyone know the best way to improve the fuel mileage on a 5.9? I recently bought a Ram 1500 with a 5.9 in it, and the fuel mileage is somewhat lower than I think it ought to be. I have had previous experience with a 4.7, but not this engine. I have been a mechanic most of my life, and just getting into this engine. Any help would be appreciated.

 

What kind of mileage are you getting? What size tires? What gears in the axle? How many miles on the truck? Any mods? What size shoe do you wear?

 

Full tune up, repair the plenum, open up the exhaust, light right foot. Not much else you can do about it.

 

lol you bought the wrong truck if you are going for fuel economy.

 

you will not get fuel mileage out of these trucks at best I get around 12 miles to the gallon with a new rebuilt motor with some goodies added on, full tank of go juice gets me roughly 250 miles.

 

I would think you should be able to do better than that....... I get about 12 on my 195,000 mile, tired ol' 360....... How old are your O2's?

 

I will second the emotion

 

ive got a 6 inch liftt on 30s, new plenum, cold air intake, and tuned by hemifever running on 91 octane, and i still get 11 or 12, i do only drive in town and go up a lot of hills.

 

I'm at 183k and I'm getting 13-15mpg (info in sig).
5.2 and 5.9 don't have much of a difference in mpg.

 

200 miles before i fill up from a full tank. i could go further but i dont like the idea of cooking my fuel pump....again. lol