I have a 2003 Dodge Cummins diesel, 4 door long bed, 2 WD geared for the highway (sorry can't remember the ratio). I have 195,000 miles on this truck.

I typically get 21-22 driving around town in bad traffic. At 65 on the interstate I get 25.5. Hell, at 55 I have gotten almost 30. It has been a great truck.

I just had the oil changed (Rotella 15-40) and had the tires rotated and pressure checked to 50 in fron and 70 in back.

My mileage went from 21.5 to 18. this is the worst mikleage I have ever gotten.

We chacked the air filter, even though I had changed it recently. We checked for a fuel leak. No leaks.

Any ideas why this dramatic change for the worse?[/align]

 

You could try this post in the Diesel section... they may have more anwers for you..

 

i'm going to move this post over to the CTD section. You will get better answers there.