2026 head-to-head · Full-Size Pickup
2026 GMC Sierra Diesel vs Ram 1500
MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.
On fuel costs these two are nearly tied. Driving 15,000 miles a year with $3.70/gal diesel fuel and $3.10/gal regular gas, the most efficient 2026 GMC Sierra Diesel (25 MPG) costs about $2,220 a year to fuel and the 2026 Ram 1500 (21 MPG) about $2,214.
Your numbers
Change these to match your driving and local prices. Every figure and chart on this page updates.
Fuel cost over 10 years
- GMC Sierra Diesel
- Ram 1500
Side by side
| GMC Sierra Diesel | Ram 1500 | |
|---|---|---|
| $2,220 | Your annual fuel cost | $2,214 |
| 25 MPG | Combined efficiency | 21 MPG |
| 23 MPG | City | 18 MPG |
| 28 MPG | Highway | 25 MPG |
| 402 g/mi | Tailpipe CO₂ (g/mi) | 433 g/mi |
| 5/10 | EPA fuel economy score | 4/10 |
| 4/10 | EPA greenhouse gas score | 4/10 |
| Diesel | Powertrain | Gas |
| Diesel | Fuel | Regular gasoline |
| 3.0L 6-cyl turbo | Engine / motor | 3.0L 6-cyl turbo |
| 10-speed automatic | Transmission | 8-speed automatic |
| RWD | Drivetrain | RWD |
✓ marks the better value. EPA scores run 1–10 (10 is best). Volumes come from the EPA interior volume index and aren't published for every body style.
GMC Sierra Diesel vs Ram 1500 across model years
- GMC Sierra Diesel
- Ram 1500
Annual fuel cost of the most efficient configuration of each model year, at your prices. Click a point to open that year.
How they differ
Among 21 2026 full-size pickups, the GMC Sierra Diesel ranks 15th and the Ram 1500 14th for lowest fuel cost.
The powertrains differ: the GMC Sierra Diesel is a diesel, while the Ram 1500 is a conventional gas model.
Frequently asked questions
Which is more fuel-efficient, the 2026 GMC Sierra Diesel or the 2026 Ram 1500?
Measured by cost to drive, the Ram 1500. The GMC Sierra Diesel is rated 25 MPG combined and the Ram 1500 21 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2026 GMC Sierra Diesel vs. the Ram 1500 per year?
At 15,000 miles a year with $3.70/gal diesel fuel and $3.10/gal regular gas, about $2,220 for the GMC Sierra Diesel and $2,214 for the Ram 1500.
GMC Sierra Diesel vs Ram 1500 in other years
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