I have a 2006 DODGE 2500 QC 4X4 with a Cummins, and it pulls great. The previous trailer we had only weighed 5000# and now we have a 5th wheel weighing 10,500# empty and I don't know its there. We have an automatic transmission and at 70 mph its at 2000 rpm. Good luck in your decision, Cummins...