2021 head-to-head · Subcompact Car
2021 Mercedes-Benz C-Class vs Porsche 911
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 Mercedes-Benz C-Class 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 $2,821 for the 2021 Porsche 911 (21 MPG). That's roughly $627 a year, or about $3,135 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
- Mercedes-Benz C-Class
- Porsche 911
Side by side
| Mercedes-Benz C-Class | Porsche 911 | |
|---|---|---|
| $2,194 | Your annual fuel cost | $2,821 |
| 27 MPG | Combined efficiency | 21 MPG |
| 24 MPG | City | 18 MPG |
| 33 MPG | Highway | 25 MPG |
| 79 cu ft | Passenger volume | 70 cu ft |
| 10 cu ft | Cargo volume | 5 cu ft |
| 330 g/mi | Tailpipe CO₂ (g/mi) | 425 g/mi |
| 6/10 | EPA fuel economy score | 4/10 |
| 6/10 | EPA greenhouse gas score | 4/10 |
| Gas | Powertrain | Gas |
| Premium gasoline | Fuel | Premium gasoline |
| 2.0L 4-cyl turbo | Engine / motor | 3.0L 6-cyl turbo |
| 9-speed automatic | Transmission | 7-speed manual |
| 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.
Mercedes-Benz C-Class vs Porsche 911 across model years
- Mercedes-Benz C-Class
- Porsche 911
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 C-Class has more passenger space (79 vs. 70 cu ft); the Mercedes-Benz C-Class has more cargo space (10 vs. 5 cu ft).
Among 34 2021 subcompact cars, the Mercedes-Benz C-Class ranks 16th and the Porsche 911 25th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2021 Mercedes-Benz C-Class or the 2021 Porsche 911?
Measured by cost to drive, the Mercedes-Benz C-Class. The Mercedes-Benz C-Class is rated 27 MPG combined and the Porsche 911 21 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2021 Mercedes-Benz C-Class vs. the Porsche 911 per year?
At 15,000 miles a year with $3.95/gal premium gas, about $2,194 for the Mercedes-Benz C-Class and $2,821 for the Porsche 911.
Which has more cargo space?
The Mercedes-Benz C-Class, with 10 cu ft of luggage volume versus 5 cu ft (EPA interior volume index).
Mercedes-Benz C-Class vs Porsche 911 in other years
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