My 1 owner 99 2500 4x4 QC 3.55 has gotten a best of 15.1. It has the Hughes plenum kit, a high-flow cat, Mobil 1 10W30, and 80 psi in the tires.

You are getting 10+ MPG more than anyone I have heard of. There is a huge MPG thread on the Dodge Talk forum. Nobody is near 20 MPG. How do you explain your astounding gas mileage? Can you post a picture of your trip computer? Thanks