A Dodge Ram 2500 pickup truck equipped with a Cummins diesel engine averages about 17.5 miles per gallon in general driving, and almost 20 MPG on the highway, as of 2015. The 6.7-liter, six-cylinder turbocharged engine from Cummins is the only diesel engine available on the Ram 2500.
The Cummins diesel engine makes 370 horsepower and 800 foot-pounds of torque. The Ram 2500 with this engine can tow up to 17,000 pounds and carry a payload of 2,180 pounds. With a full fuel tank, the truck weighs 8,000 pounds. The EPA classifies the Dodge Ram 2500 as a heavy-duty vehicle, and therefore not provide official mileage estimates for this truck.