2015 head-to-head · Two-Seater
2015 Mercedes-Benz SL-Class vs Porsche 918 Spyder
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 · 4.6L 8-cyl · 7-speed dual-clutch · 67 MPGe + 22 MPG
The 2015 Porsche 918 Spyder is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas and 18¢/kWh electricity, it costs about $2,259 a year to fuel (67 MPGe + 22 MPG), versus $2,576 for the 2015 Mercedes-Benz SL-Class (23 MPG). That's roughly $317 a year, or about $1,583 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 918 Spyder
Side by side
| Mercedes-Benz SL-Class | Porsche 918 Spyder | |
|---|---|---|
| $2,576 | Your annual fuel cost | $2,259 |
| 23 MPG | Combined efficiency | 67 MPGe + 22 MPG |
| 20 MPG | City | 68 MPGe / 20 MPG |
| 27 MPG | Highway | 66 MPGe / 24 MPG |
| — | Electricity use (kWh/100 mi) | 50 kWh |
| — | Driving range | 420 mi |
| — | All-electric range | 12 mi |
| 393 g/mi | Tailpipe CO₂ (g/mi) | 277 g/mi |
| 5/10 | EPA fuel economy score | 7/10 |
| 5/10 | EPA greenhouse gas score | 8/10 |
| — | Charge time at 240V | 3 hrs |
| Gas | Powertrain | Plug-in hybrid |
| Premium gasoline | Fuel | Premium gas + electricity |
| 3.0L 6-cyl turbo | Engine / motor | 4.6L 8-cyl |
| 7-speed automatic | Transmission | 7-speed dual-clutch |
| RWD | Drivetrain | AWD |
✓ 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 918 Spyder across model years
- Mercedes-Benz SL-Class
- Porsche 918 Spyder
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 33 2015 two-seaters, the Mercedes-Benz SL-Class ranks 15th and the Porsche 918 Spyder 7th for lowest fuel cost.
The powertrains differ: the Mercedes-Benz SL-Class is a conventional gas model, while the Porsche 918 Spyder is a plug-in hybrid.
Frequently asked questions
Which is more fuel-efficient, the 2015 Mercedes-Benz SL-Class or the 2015 Porsche 918 Spyder?
Measured by cost to drive, the Porsche 918 Spyder. The Mercedes-Benz SL-Class is rated 23 MPG combined and the Porsche 918 Spyder 67 MPGe + 22 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2015 Mercedes-Benz SL-Class vs. the Porsche 918 Spyder per year?
At 15,000 miles a year with $3.95/gal premium gas and 18¢/kWh electricity, about $2,576 for the Mercedes-Benz SL-Class and $2,259 for the Porsche 918 Spyder.
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