What fuel mileage does a 6.7 Cummins get?
In general, a Ram with the 6.7-liter Cummins turbodiesel can average roughly 15–20 mpg in mixed daily driving, with highway cruising often in the low- to mid-20s when not towing or carrying heavy loads. Actual figures vary widely based on year, transmission, drivetrain, payload, and driving habits.
What affects fuel economy in a 6.7 Cummins-powered Ram
The following factors can cause large swings in miles per gallon for 6.7 Cummins-equipped trucks:
- Drivetrain configuration (4x2 vs. 4x4) and axle gearing
- Payload and towing weight, including max-tow configurations
- Vehicle weight and overall aerodynamics (cab/bed setup, aftermarket equipment)
- Transmission type and gear ratios (older 6-speed automatics vs. newer 8-speed designs)
- Tire type, size, and inflation pressure
- Maintenance and engine condition (air filter, fuel filter, DEF system, oil changes)
- Driving style and conditions (highway cruising vs. city stop-and-go, elevation, wind)
Understanding these factors helps explain why real-world mpg often differs from EPA estimates and what drivers can do to maximize efficiency.
Typical mpg ranges by configuration
The following ranges reflect common setups in recent model years and are intended as guidance. Exact numbers will appear on the vehicle’s EPA window sticker and can vary by year, trim, and options.
- 4x2, light payload (unloaded or light work use): City 14–16 mpg, Highway 20–23 mpg, Combined 17–19 mpg
- 4x4, light payload: City 13–15 mpg, Highway 19–22 mpg, Combined 16–18 mpg
- Moderate towing or payload (tow/haul in the range of several thousand pounds): City 12–14 mpg, Highway 17–20 mpg, Combined 15–18 mpg
- Heavy towing or max payload (near or at gross vehicle weight): City 9–12 mpg, Highway 14–18 mpg, Combined 11–15 mpg
Note: Real-world results depend heavily on the factors listed above. Owners towing heavy loads or operating in hilly terrain will typically see lower numbers, while long highway drives with modest loads can yield the higher end of these ranges.
Tips to maximize fuel efficiency with a 6.7 Cummins
Implementing practical changes can squeeze more miles out of a tank without sacrificing safety or capability. The guidance below is designed to help both daily drivers and occasional tow-ers improve efficiency.
- Keep tires inflated to the manufacturer’s recommended pressure and use fuel-efficient tires when possible
- Plan trips to avoid unnecessary idling and reduce stop-and-go driving where feasible
- Use cruise control on highways to maintain a steady speed
- Maintain a consistent driving speed, especially on flat terrain
- Follow regular maintenance: replace air and fuel filters as recommended, and service DEF systems
- Avoid excessive payload and remove unused carriers or racks when not towing
- Use the appropriate tow/haul mode and proper gearing for towing to optimize engine efficiency
By applying these practices, drivers can often improve their real-world mpg by a few tenths to a few miles per gallon, depending on conditions and how the truck is configured.
Summary
The 6.7 Cummins delivers strong torque for towing and steady highway cruising, but fuel economy varies widely with payload, towing, and driving conditions. Expect roughly 15–20 mpg combined in typical mixed use, with highway numbers commonly in the low- to mid-20s when not towing heavily. For the most accurate figure, check the EPA window sticker on a specific vehicle and consider your typical use-case when estimating fuel costs.
Summary: The exact fuel mileage of a 6.7 Cummins is highly dependent on configuration and usage. Real-world results often fall in the mid-teens to low-twenties mpg, with significant variation based on payload, towing, and driving style. Always refer to official EPA ratings for the exact model year and trim you’re evaluating, and use the practical tips above to maximize efficiency.
