2025 head-to-head · Subcompact Car
2025 Mercedes-Benz SL-Class Plug-in Hybrid 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.
AWD · 4.0L 8-cyl turbo · 9-speed automatic · 29 MPGe + 18 MPG
On fuel costs these two are nearly tied. Driving 15,000 miles a year with 18¢/kWh electricity and $3.95/gal premium gas, the most efficient 2025 Mercedes-Benz SL-Class Plug-in Hybrid (29 MPGe + 18 MPG) costs about $2,770 a year to fuel and the 2025 Porsche 911 (21 MPG) about $2,821.
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 Plug-in Hybrid
- Porsche 911
Side by side
| Mercedes-Benz SL-Class Plug-in Hybrid | Porsche 911 | |
|---|---|---|
| $2,770 | Your annual fuel cost | $2,821 |
| 29 MPGe + 18 MPG | Combined efficiency | 21 MPG |
| 33 MPGe / 16 MPG | City | 18 MPG |
| 25 MPGe / 22 MPG | Highway | 25 MPG |
| 43 kWh | Electricity use (kWh/100 mi) | — |
| 350 mi | Driving range | — |
| 11 mi | All-electric range | — |
| 76 cu ft | Passenger volume | 70 cu ft |
| 2 cu ft | Cargo volume | 5 cu ft |
| 379 g/mi | Tailpipe CO₂ (g/mi) | 424 g/mi |
| 4/10 | EPA fuel economy score | 4/10 |
| 5/10 | EPA greenhouse gas score | 4/10 |
| 1.1 hrs | Charge time at 240V | — |
| Plug-in hybrid | Powertrain | Gas |
| Premium gas + electricity | 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 Plug-in Hybrid vs Porsche 911 across model years
- Mercedes-Benz SL-Class Plug-in Hybrid
- 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 Plug-in Hybrid has more passenger space (76 vs. 70 cu ft); the Porsche 911 has more cargo space (5 vs. 2 cu ft).
Among 30 2025 subcompact cars, the Mercedes-Benz SL-Class Plug-in Hybrid ranks 22nd and the Porsche 911 23rd for lowest fuel cost.
The powertrains differ: the Mercedes-Benz SL-Class Plug-in Hybrid is a plug-in hybrid, while the Porsche 911 is a conventional gas model.
Frequently asked questions
Which is more fuel-efficient, the 2025 Mercedes-Benz SL-Class Plug-in Hybrid or the 2025 Porsche 911?
Measured by cost to drive, the Mercedes-Benz SL-Class Plug-in Hybrid. The Mercedes-Benz SL-Class Plug-in Hybrid is rated 29 MPGe + 18 MPG combined and the Porsche 911 21 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2025 Mercedes-Benz SL-Class Plug-in Hybrid vs. the Porsche 911 per year?
At 15,000 miles a year with 18¢/kWh electricity and $3.95/gal premium gas, about $2,770 for the Mercedes-Benz SL-Class Plug-in Hybrid and $2,821 for the Porsche 911.
Which has more cargo space?
The Porsche 911, with 5 cu ft of luggage volume versus 2 cu ft (EPA interior volume index).
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