2026 head-to-head · Subcompact Car
2026 Mercedes-Benz SL-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 2026 Porsche 911 is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,821 a year to fuel (21 MPG), versus $3,703 for the 2026 Mercedes-Benz SL-Class (16 MPG). That's roughly $882 a year, or about $4,408 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 SL-Class
- Porsche 911
Side by side
| Mercedes-Benz SL-Class | Porsche 911 | |
|---|---|---|
| $3,703 | Your annual fuel cost | $2,821 |
| 16 MPG | Combined efficiency | 21 MPG |
| 13 MPG | City | 18 MPG |
| 20 MPG | Highway | 25 MPG |
| 76 cu ft | Passenger volume | 70 cu ft |
| 6 cu ft | Cargo volume | 5 cu ft |
| 558 g/mi | Tailpipe CO₂ (g/mi) | 424 g/mi |
| 3/10 | EPA fuel economy score | 4/10 |
| 3/10 | EPA greenhouse gas score | 4/10 |
| Gas | Powertrain | Gas |
| Premium gasoline | Fuel | Premium gasoline |
| 4.0L 8-cyl turbo | Engine / motor | 3.0L 6-cyl turbo |
| 9-speed automatic | Transmission | 8-speed dual-clutch |
| AWD | 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 SL-Class vs Porsche 911 across model years
- Mercedes-Benz SL-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 SL-Class has more passenger space (76 vs. 70 cu ft); the Mercedes-Benz SL-Class has more cargo space (6 vs. 5 cu ft).
Among 26 2026 subcompact cars, the Mercedes-Benz SL-Class ranks 26th and the Porsche 911 18th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2026 Mercedes-Benz SL-Class or the 2026 Porsche 911?
Measured by cost to drive, the Porsche 911. The Mercedes-Benz SL-Class is rated 16 MPG combined and the Porsche 911 21 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2026 Mercedes-Benz SL-Class vs. the Porsche 911 per year?
At 15,000 miles a year with $3.95/gal premium gas, about $3,703 for the Mercedes-Benz SL-Class and $2,821 for the Porsche 911.
Which has more cargo space?
The Mercedes-Benz SL-Class, with 6 cu ft of luggage volume versus 5 cu ft (EPA interior volume index).
Mercedes-Benz SL-Class vs Porsche 911 in other years
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