2021 head-to-head · Subcompact Car
2021 BMW i3 vs Mercedes-Benz A-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 i3 is the cheaper one to run. Driving 15,000 miles a year with 18¢/kWh electricity and $3.95/gal premium gas, it costs about $805 a year to fuel (113 MPGe), versus $2,043 for the 2021 Mercedes-Benz A-Class (29 MPG). That's roughly $1,239 a year, or about $6,193 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 i3
- Mercedes-Benz A-Class
Side by side
| BMW i3 | Mercedes-Benz A-Class | |
|---|---|---|
| $805 | Your annual fuel cost | $2,043 |
| 113 MPGe | Combined efficiency | 29 MPG |
| 124 MPGe | City | 25 MPG |
| 102 MPGe | Highway | 36 MPG |
| 29.8 kWh | Electricity use (kWh/100 mi) | — |
| 153 mi | Driving range | — |
| 84 cu ft | Passenger volume | 91 cu ft |
| 15 cu ft | Cargo volume | 9 cu ft |
| 0 g/mi | Tailpipe CO₂ (g/mi) | 309 g/mi |
| 10/10 | EPA fuel economy score | 6/10 |
| 10/10 | EPA greenhouse gas score | 6/10 |
| 7 hrs | Charge time at 240V | — |
| Electric | Powertrain | Gas |
| Electricity | Fuel | Premium gasoline |
| Electric motor (135 kW) | Engine / motor | 2.0L 4-cyl turbo |
| Single-speed | Transmission | 7-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 i3 vs Mercedes-Benz A-Class across model years
- BMW i3
- Mercedes-Benz A-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
Per EPA interior volume figures, the Mercedes-Benz A-Class has more passenger space (91 vs. 84 cu ft); the BMW i3 has more cargo space (15 vs. 9 cu ft).
Among 34 2021 subcompact cars, the BMW i3 ranks 1st and the Mercedes-Benz A-Class 12th for lowest fuel cost.
Because the BMW i3 is fully electric, it has no tailpipe emissions and its running cost depends almost entirely on your electricity rate. Cheap overnight home charging widens its advantage over the Mercedes-Benz A-Class; relying on DC fast chargers can erase it.
Frequently asked questions
Which is more fuel-efficient, the 2021 BMW i3 or the 2021 Mercedes-Benz A-Class?
Measured by cost to drive, the BMW i3. The BMW i3 is rated 113 MPGe combined and the Mercedes-Benz A-Class 29 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2021 BMW i3 vs. the Mercedes-Benz A-Class per year?
At 15,000 miles a year with 18¢/kWh electricity and $3.95/gal premium gas, about $805 for the BMW i3 and $2,043 for the Mercedes-Benz A-Class.
Which has more cargo space?
The BMW i3, with 15 cu ft of luggage volume versus 9 cu ft (EPA interior volume index).
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