2018 head-to-head · Two-Seater
2018 Mercedes-Benz SL-Class vs Porsche Cayman
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 2018 Porsche Cayman is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,370 a year to fuel (25 MPG), versus $2,576 for the 2018 Mercedes-Benz SL-Class (23 MPG). That's roughly $206 a year, or about $1,030 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 Cayman
Side by side
| Mercedes-Benz SL-Class | Porsche Cayman | |
|---|---|---|
| $2,576 | Your annual fuel cost | $2,370 |
| 23 MPG | Combined efficiency | 25 MPG |
| 20 MPG | City | 22 MPG |
| 28 MPG | Highway | 29 MPG |
| 383 g/mi | Tailpipe CO₂ (g/mi) | 353 g/mi |
| 5/10 | EPA fuel economy score | 5/10 |
| 5/10 | EPA greenhouse gas score | 5/10 |
| Gas | Powertrain | Gas |
| Premium gasoline | Fuel | Premium gasoline |
| 3.0L 6-cyl turbo | Engine / motor | 2.0L 4-cyl turbo |
| 9-speed automatic | Transmission | 7-speed dual-clutch |
| 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 SL-Class vs Porsche Cayman across model years
- Mercedes-Benz SL-Class
- Porsche Cayman
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 30 2018 two-seaters, the Mercedes-Benz SL-Class ranks 10th and the Porsche Cayman 9th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2018 Mercedes-Benz SL-Class or the 2018 Porsche Cayman?
Measured by cost to drive, the Porsche Cayman. The Mercedes-Benz SL-Class is rated 23 MPG combined and the Porsche Cayman 25 MPG (EPA, most efficient configuration of each).
How much does it cost to fuel the 2018 Mercedes-Benz SL-Class vs. the Porsche Cayman per year?
At 15,000 miles a year with $3.95/gal premium gas, about $2,576 for the Mercedes-Benz SL-Class and $2,370 for the Porsche Cayman.
Mercedes-Benz SL-Class vs Porsche Cayman in other years
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