I've got an 01 2500, 4x4, quad cab. I just had the inj, pump replaced at 175k miles. Stock rebuilt as far as I know. the truck has an K&N air cleaner and 4 inch exhaust. I pull a 31 foot travel trailer and usually gross out anywhere from 18 to 19 thousand pounds. Other than that looong split between 3rd and 4th (it's a 5 speed), I really enjoy the truck. I hear a lot of info about upgrades and the power and fuel mileage increases they give you. I.m getting ready to head cross country ( ore to N.C) and wondering,"will they really help?) Right now it gets an average of 18mpg by itself and 11 to 14 with the trailer(9 to 10 in a strong head wind) Thanks. This is my first post, hope it's not too long.

What upgrades are you curious about? You seem to be pulling some decent numbers for mileage already. The exhaust and air filter do let it breath easier which you may have noticed. One thing though, ditch the K&N and get a BHAF, K&N's have terrible filtration characteristics. http://forum.mopar1973man.com/showthread.php/18-BHAF-filters... Your posts can be as long as you want, the more info you give, the more help we can provide

different injectors might give a different spray pattern. if your lift pump starts getting weak it will starve your injection pump and give bad mileage(among other things)

What upgrades are you curious about? You seem to be pulling some decent numbers for mileage already. The exhaust and air filter do let it breath easier which you may have noticed. One thing though, ditch the K&N and get a BHAF, K&N's have terrible filtration characteristics. http://forum.mopar1973man.com/showthread.php/18-BHAF-filters... Your posts can be as long as you want, the more info you give, the more help we can provide

I definitely second the suggestion to get rid of the K&N filter for the BHAF. A set of EDM 90 hp injectors and an Edge EZ or Smartie would make for a very moderate, reliable, but noticable improvment in hp and fuel economy. So far, in my limited experience, the best and most noticable fuel economy mod lies in moderation of the right foot. Minimize boost pressure to stay below 4 psi as much as possible and keep the rpms between 1400 and 1600. Not always easy or practical when pulling a heavy load especially on hills.

I agree with both the guys about the K&N... why bother washing a filter constantly and breaking down the filter media to the point of passing dust. BHAF will last 5 years and 100K miles easy without washing, oiling, or even messing with it. Why? Simple because the fact the filter is so huge that the dust can't be held to the media by vacuum so with road vibration the dust is shook off and it becomes self cleaning lets say... http://forum.mopar1973man.com/attachment.php?attachmentid=923 As for mileage gains you need to consider a enhancement box of some sort. Like myself I got a Edge Comp and run it wide open 5x5 and been tipping the MPG at about 20-21 MPG typically. A good fuel system. A good lift pump will help keep the VP44 injection pump healthy longer so the MPG's will not degree as much. AirDog 100 or AirDog 150 both come with filter and filter down to about 2 microns compared to stock filter at 10 microns. Ah heck... There is even more information over here... http://mopar.mopar1973man.com/cummins/general/better-mpgs/better-mpgs.htm