17-18 MPG mixed highway (65 MPH) and city driving.
9-10 towing 14,000 LB 5th wheel.
All hand calculated miles by gallons used.
I've owned 4 Dodge Cummins diesels (99 dually auto, 05 dually 6 speed manual, 06 SRW auto, 09 SRW auto) and this 09 6. 7 68RFE is the best towing and cruising Dodge Cummins I have ever owned.