Hello all,
I have a customer where i work that asked me to try and find some info for him as he doesn't have a computer. He has a stock 2005 2500 with 260000 miles on it. It started to run poorly so he took it back to the dealer and was told it needed new injectors. The mechanic in the shop told him to get them elsewhere as the ones from Dodge were junk. He got a set of remans from Metro Fuel Injector Service in Springfield, MA and put them in. It runs great now except his fuel mileage has been cut in half. Before he was getting 26-28 mpg and now he's getting 13-15 mpg. The overhead display and when he does the math by hand are the same so the display is probably accurate. He took the truck back to the dealer and and there's no codes showing to explain the mileage loss. He said if it was only like a 2-5 mile loss it wouldn't bother him but he would like to get the mileage back because he goes to Montana a couple times a year. Any ideas or suggestions I could give him? Thanks in advance. Stewart

 

I do not believe that truck ever got that kind of good milage. The overhead readout is not correct. Best guess on a good day would be 18 mpg if you were trying to drive easy.

 

He claims that when he goes to Montana he fills the tank here fills it up again in western Ohio and then again when he gets into Montana and still has at least half a tank when he gets to his place out there so it had to have gotten reasonably good mileage before the injectors needed to be replaced

 

Those were super experimental secret injectors that Cummins lost track of.

Seriously, I could see 20-21 driving reasonably with a US Gallon, but no way 26-28, especially at speed.

Another factor is winter fuel, Soon I will gain a solid 3-4 MPG when summer fuel hits again.

 

2wd, skinny tires, gearvendors...maybe 21 frequently.

I was at the higher end of Fuel Economy before my lift compared to most on here who hand-calc and I saw 20mpg one time in 76000 miles. I averaged 17.5mpg, I would kiss 18.5 occasionally, but it was darn hard to get beyond that. MY 20mpg trip was coming down out of Echo Summit (7k alt) and drafting a rig on I-5 (Sealevel).

Here's my guess...

He didn't hand-calc prior to injector replacement, when the dealer installed his replacement injectors they flashed the truck and the OH is now more in line with actual mileage.

Now it is quite possible that he saw a significant decrease in FE with the new injectors but I can't imagine it'd be more than -3mpg.

 

I'll have to agree with the above statements...

No way with a 2005 he ever got the mileage claimed. I will agree with the 20-21 mpg estimates. When my truck was stock I was able to squeeze out a few 700 mile tankfuls and that was not 26-28mpg.
2005 and up got worse mileage than my 2004.

I think he is relying on the "lie-o-meter" (overhead) way too much. It is not at all accurate.

So, to summarize, he did not get as good of mileage as he claimed originally. He likely did get some reman injectors that are not all that great and has cost him mileage. I will suspect the truth is in the middle.

Lesson: don't buy cheap injectors!