2021 head-to-head · Small SUV
2021 BMW X3 vs Mercedes-Benz GLB-Class
MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.
The 2021 BMW X3 is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,194 a year to fuel (27 MPG), versus $2,279 for the 2021 Mercedes-Benz GLB-Class (26 MPG). That's roughly $84 a year, or about $422 over five years.
Your numbers
Change these to match your driving and local prices. Every figure and chart on this page updates.
Fuel cost over 10 years
- BMW X3
- Mercedes-Benz GLB-Class
Side by side
| BMW X3 | Mercedes-Benz GLB-Class | |
|---|---|---|
| $2,194 | Your annual fuel cost | $2,279 |
| 27 MPG | Combined efficiency | 26 MPG |
| 25 MPG | City | 23 MPG |
| 29 MPG | Highway | 31 MPG |
| 332 g/mi | Tailpipe CO₂ (g/mi) | 337 g/mi |
| 6/10 | EPA fuel economy score | 5/10 |
| 6/10 | EPA greenhouse gas score | 5/10 |
| Gas | Powertrain | Gas |
| Premium gasoline | Fuel | Premium gasoline |
| 2.0L 4-cyl turbo | Engine / motor | 2.0L 4-cyl turbo |
| 8-speed automatic | Transmission | 8-speed dual-clutch |
| RWD | Drivetrain | FWD |
✓ 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.
BMW X3 vs Mercedes-Benz GLB-Class across model years
- BMW X3
- Mercedes-Benz GLB-Class
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 92 2021 small SUVs, the BMW X3 ranks 66th and the Mercedes-Benz GLB-Class 74th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2021 BMW X3 or the 2021 Mercedes-Benz GLB-Class?
Measured by cost to drive, the BMW X3. The BMW X3 is rated 27 MPG combined and the Mercedes-Benz GLB-Class 26 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2021 BMW X3 vs. the Mercedes-Benz GLB-Class per year?
At 15,000 miles a year with $3.95/gal premium gas, about $2,194 for the BMW X3 and $2,279 for the Mercedes-Benz GLB-Class.
BMW X3 vs Mercedes-Benz GLB-Class in other years
More 2021 comparisons
BMW X3 vs…
Or compare the 2021 BMW X3 with anything else: