Here are a few points about Dodge that might help:
In 2003 with the new body style change, called the third generation, Dodge went to AAM axles. These are very good axles and are available in 4.10, 3.73, and now, 3.42.
The best mileage comes from the trucks built before Jan 1, 2004. These are called '04 model and come with up to 305 HP in the HO (high output) model. There is also an SO (standard Output) model that was mainly in '03 and for California. These also have a five speed manual instead of the six speed, lighter duty axles and catalytic converters. The '03 and '04 HO models have no cat. After Jan 1 they are called '04.5 and have a catalytic converter and different fuel programming. The mileage dropped by about 1.5 MPG. When the 6.7 engine came out with the particulate filter and all the stuff associated with it, the mileage went way down. But the 6.7s come with the new 6 speed auto that everybody loves. This is a Dodge tranny. The chassis cab models with the 6.7 come with an Aisin 6 speed auto that is also a very good and rugged tranny.
I have an '04 with 200,000 miles on it. The main problem area has been the front suspension. Namely, the ball joints, U joints, linkage and track bar bushings. These have all been upgrade by now and work well. I also installed manual locking hubs on mine.
With the third gens you can add lots of power with a simple programmer that can also improve the mileage. Some programmers are way better than others and they work in different ways. Throughout the third gen category, there have been a lot of small refinements, so a liitle research goes a long way in knowing what to expect and how to deal with it. Mine, for instance had a weak lift pump that failed. I changed to a completely different design and have been fine since.
The mileage computer and display are notoriously innacurate. It works by computing vehicle speed, fuel pressure and the amount of time the injectors are energized. When you see a mileage number that is extremely high, as mentioned in an earlier post, it is because the truck is coasting, the computer has been reset and the injection is actually off. The mileage at that instantaneous point is almost infinite, although it is the overall average that counts. Sitting and running in the driveway is zero mileage. Pulling onto the highway might be 5 MPG. Light throttle on level ground might be 24 MPG. It all makes sense. But the readings, on average, will be a mile or two off. It's mainly good to show trends and comparisons with other trips.
The one thing that has been consistent with the Cummins is it's long life, extreme towing ability and reliability. Before buying another brand be sure you do some research into that particluar engine's general history! A good example is the Ford Power Stroke which came in different dispalcements and was changed in various years. Some have been VERY bad and some have been good. Beware. Chevy Duramax engines had some bugs in the beginning , but seem to be doing fine now. One thing though, the serviceability and simplicity of the Cummins is impossible to beat compared to a V8 with a central turbo. Ford pickups require the removal of the entire cab to work on relatively simple engine problems! With the Dodge you just reach in a do it. Turbo, injectors, starter, injection pump, etc. HUGE difference.
