98 long bed diesel is a 35 gallon tank. I just looked it up in the owners manual. That is a 2500 with single tank.

 

well im picking up my first cummins this saturday...04 QCSB 4x4. was told by the owner that he got over 600per tank without pushing it too far. so ill be sure to test that. after i do, ill post up my results.

anyway, needless to say....im very excited about this truck and saturday cant come fast enough!

 

Congrats on the new truck! Lots of luck with it. Oh and welcome to the dark side.

 

i have a 93 d350 5.9 12v cummins all stock and i get 18.6 in town 30gal tank so i get around 560 per tank but i fill at 400 to 425 and still have 7gal or to go