I drive a 2013 Ram 2500 Laramie 4x4 quad cab with a Cummins I bought new. I love this truck after years of Ford diesel ownership
I set lash to the tight side of factory the exhaust and tighter on the intake, took out the silencer in the intake and it runs strong
18.5 mpg around town with rural mix, 16.5 city, and 23-26 pure highway depending how hard I am hitting it. Cruise control with 10K on the bumper, all you hear is turbo sound change, never downshifts.
Cummins are bit more noisy than a Powerstroke or Duramax, but they make power at lower rpm and are just pleasant to drive