Ok -- here we go, another mileage question.

I have a 2004 2500 4x4 Cummins with 6500 miles now and I am getting around 11.5 to 12.1 MPG with a mix of city and highway driving... Is this normal? I have rough starts in the morning -- small amount of white smoke and a rough idle for the first 20 seconds or so then, it clears up -- dealer service dept. did the update and asked for 40 hours of driving -- did that -- oil is AMSOIL... INPUT? IDEAS? Also, I have a shimmy around 50-55 MPH in the steering wheel that is new...

Thanks in advance for your time and input...

Jeff

 

Need more data on your truck.
If you have an 04 with only 6500 miles on it then you need to drive it more. It's wasting away

 

My .02 is I have 3k on my truck (just owned it for 2 months) and it is bone stock except my DC dealer flashed the computor at about 1 K. Pulling a 10k trailer in mixed moderate hills and flat ground at 60-65mph I get 10.5 to 12, empty and no trailer I get 16-18. Not anthing to write home about and certainly not as good as I had hoped considering the price of the engine and now the price of diesel but I love the truck so far otherwise. Sure beats that little F-150 I had before this one!!! ps: fill out the little signature line info on your truck so we can all have a better idea of what you have.

 

Ok -- I added info -- do not know what else you wanted, but I hope this helps... I am going to drop this thing off at the dealer next week and let them keep it while I am out on my next trip and see what they can come up with...

 

ive got 6000k on mine and average 15mpg with foot in it on the hw and city, if i drive 65 with rmp at 2k, i notice the computer reads from 17-22 on hwy.

 

If your having rough starts in the morning with smoke and you live in Houston - I would say you have an injector going out. And this may affect your fuel economy. Sound alot like mine before the injector was replaced.

 

That sounds along the lines of what i was thinking too... The service rep is exptecting the same thing too... I am going to leave it with them for a few days... Did your mileage increase with the injector replacement? Thanks in advance...

 

My mileage did improve a little, but when the injector went out on my truck, I had 11k miles and over half of that was towing so the engine was a little more broke in then yours. How much city driving are you doing? How much of that is stop and go Like on Highway 6 in Missouri City. It seems like when you get up to speed you have to stop again. Getting a 7000lb truck up to speed just to stop again every half mile uses a lot of fuel. How much AC are you running? All these things affect fuel economy. My real world fuel economy is almost 20mpg (19.9) running empty, under 70mph, with the AC off. around town it drops down to about 15 depending on how fast I want to accelerate to the next stop light. We'rre relocating to Houston and it seems everyone there has two positions on the accelerator - off & floored!

If you have more than one injector bad, I wouldn't doubt that your economy will increase. Let us know what happens. Also which dealership are you going to.

 

I am using Goodson in Spring. I am on the north side of Housotn in the Spring / Tomball area. The thing that is concerning me is the rough starts with the white smoke in the morning - cold or warm days... Most of my driving is from Tomball to IAH - about 20 - 25 miles... I have not made a road trip yet, but will soon and will give a test run after the shop visit this week. I am going on a 300 + mile trip... The steering wheel woble at around 50 MPH is concerning too... This is new... Any ideas?

 

kjw, a lot of folks are finding tires to be the cause of their woble. Try rotating your tires and see if there is a change.

 

Definitely the injectors and more than likely its more than 2

 

Yeah....its the injector....and the wobble...you should rotate your tires every other oil change....good luck

 

i live in colorado and when the temp is below 40 degrees in the morning the truck will start with a little white smoke and the whole truck shakes a little bit, then after about 5 seconds it clears up and idles perfectly

 

I would expect this out of a diesel engine in CO when the ambient temps are below 50 deg F, but I would not expect it at 75 deg. F... I think that an injector or more than one is leaking down over night... The shop has it now and I will give them this week to take another look and see what they can figure out... Thanks for the info...


Jeff

 

I think you have a problem. My truck has 11k miles on it now and the mileage has steadily improved since new, but it was never as low as you describe even before the TSB reflash, which I assume you have done. I have 183 miles since my last fill, and my combined driving is 20.2 on my overhead, which is generally pretty accurate and never more than .7mpg off. I do drive conservatively, and here in Buzzard Breath, Wyoming city driving is a different experience. We only have eight stoplights in town. I have no strange vibrations, and I love my truck. So far it has been flawless. Unless you have a lead foot and love the jackrabbit starts and a lot of braking, something seems broke that needs fixed.