The short answer
Payback years = diesel option price ÷ (yearly gas fuel cost - yearly diesel fuel and DEF cost). With the default numbers (15,000 miles, 15 MPG gas at $3.10, 19 MPG diesel at $3.60, $5 of DEF per 1,000 miles, a $12,995 option), the diesel saves about $183 a year in fuel, so fuel savings alone would take decades to cover the option.
That's why diesel decisions usually rest on towing capacity, not fuel. On Ram heavy-duty stickers in our stock the Cummins HO was $12,995; see is the Cummins worth it?. Use your own MPG; towing changes both engines' numbers.
Calculator
Gas or diesel: fuel cost and payback
Use EPA or real-world MPG for each engine, local pump prices and the diesel option price from the window sticker. DEF is diesel exhaust fluid; enter your own estimate of its cost per 1,000 miles. Estimate only: towing, idling and winter blends change the numbers.
How to use it
- Change one number at a time to see what moves the result.
- Use numbers from the window sticker, your lender or your own fuel records.
- It runs in your browser; nothing you type is sent to us.
Related tools
All tools: fuel cost, out-the-door price, payment explainer.
Questions
Does a diesel truck pay for itself in fuel?
Usually not on fuel alone at typical mileage; run your own numbers. Towing capacity, resale and how you use the truck matter more.
What is DEF?
Diesel exhaust fluid, used by modern diesel emission systems. Consumption varies; enter your own estimate.
Next steps at Swant Graber
Swant Graber Motors (Chevrolet, Ram, Dodge): 1690 E Division Ave, Barron, WI 54812, 715-537-5657. Swant Graber Ford: 1697 E Division Ave, 715-537-9500. Search new or used inventory, or see shop near you for model-by-model answers.
