Posted: Thu Dec 23, 2004 2:27 pm
Probably found somthing wrong & did not want to say that it was messed up ( looks bad) for them.
High Output Cummins motors will have poorer fuel mileage because they make more power. Everyone around where I live notice the same thing. Your truck may take 8000-10000 miles for motor to be broke-in.
I would check with a "Good" truck repair shop that has Cummins Technicians.