This is my 1st post,, I just recently bought a new 2004.5 QC 2500 2WD AUTO so far it is awesome. I got hooked on the Cummins in 91 when my grandaddy bought a 4x4 2500 with the extra heavy duty suspension, that thing rode like a mule and wagon and was very loud inside and out,, next he bought a 2WD 3500 in 95 and this truck really got me hooked it had a nice ride but was still loud so when I compare my truck it is basically to the 95 model.. The engine is quiet but I do have some very slight pinging noise at low speeds but I am not sure if it is normal or not since there is no way to compare it to the 95.. I use the truck for daily driving and pull a trailer very seldom,, my mileage on the first tank after filling till fuel was up in the neck both times on 250 around town miles my fuel mileage was 17.59 hand calculated and the above trip computer showed 17.6 mpg. Now I am at 1,000 miles and my above computer shows 19.1mpg this is pretty much babying the truck and running around 60 mph.. One thing I have noticed is that is drops quickly if i get it up to say 70 and I don't like that since I have alot of trips and need to be able to run it faster than 60 to get my fuel mileage up. My truck is qualified for the TSB for fuel mileage problem but I am not sure to get it done or not to get the 19.1 I really have babied it. I have a few questions and will have more later I am sure,, 1 is my truck would better suit me if I could get the automatic to shift a little sooner right now it has 2 harsh shifts 1 at 40 and 1 at 50 if these could be reduced for me to say 35 and 45 it would help me and my fuel mileage out tremendously,, as some of my driving has my driving right at 40 and it is like the computer is just holding it back and running extra rpm's for nothing as soon as it shifts and hlding the throttle steady the truck just takes off and gains alot of speed.

I love reading all of your post,, i will be asking alot of questions on maintenance and such and will be trying to write in on my results and try and help out as much as possible.

Thanks

 

My overhead computer is close, but I always hand calculate my mileage. Try it, you may be better off than you think you are.

 

Hey there Nevada, My first tank that I filled the truck had 500 miles on it and it got 17.59mpg hand calculated the overhead was 17.60 so it was dead on..
Now I am at 1000 at with a few trips on this tank it is showing 19.1 so that is a good sign but to get this I have had to baby it and that is something I can't do as any speed over 60 the mileage will drop fast..

 

Welcome. I would love to get that kind of mileage but out here if ran 60 I would get rearended or cause trafic problems (at 2500 miles I am getting 17ish hwy/city). No complaints, getting 17 mpg with a HEAVY 4X4 and bigger tires at 75 - 80 mph is not so bad in my book. Next time I am at low elevation and on secondary roads I would like to see if she can pull some really good figures like you guys are getting. My overhead is off by about 1.5 - 2 MPG.