Mercedes-Benz SL-Class vs Porsche 718
The Porsche 718 is the more efficient of the two: it reaches 24 mpg combined versus 23 mpg for the Mercedes-Benz SL-Class, a 1 mpg advantage and costs about $150 less per year to fuel.
Across 4 measured categories, the Porsche 718 leads in 3. Figures are EPA test data, not manufacturer claims.
2015–2027
Mercedes-Benz SL-Class
Two Seaters · 40 configurations
Head-to-head specifications
| Metric | Mercedes-Benz SL-Class | Porsche 718 |
|---|---|---|
| Best combined MPG | 23 mpg | 24 mpg ✓ |
| Best city MPG | 21 mpg | 21 mpg |
| Best highway MPG | 28 mpg ✓ | 27 mpg |
| Lowest annual fuel costEPA estimate at 15,000 miles per year | $3,300 | $3,150 ✓ |
| Lowest CO2 output | 379 g/mi | 375 g/mi ✓ |
| Engines offered | SIDI, SIDI; Mild Hybrid, SIDI; PHEV, 6.0 | SIDI |
| Transmissions | Automatic 9-spd, Automatic 7-spd | Manual 6-spd, Automatic (AM-S7) |
| Drivetrains | All-Wheel Drive, Rear-Wheel Drive | Rear-Wheel Drive |
| Fuel types | Premium, Premium and Electricity | Premium |
| EPA class | Two Seaters | Two Seaters |
| Years covered | 2015–2027 | 2020–2025 |
| Configurations on record | 40 | 91 |
Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.
SL-Class vs 718: common questions
Which is better on gas, the Mercedes-Benz SL-Class or the Porsche 718?
The Porsche 718 is the more efficient of the two: it reaches 24 mpg combined versus 23 mpg for the Mercedes-Benz SL-Class, a 1 mpg advantage and costs about $150 less per year to fuel.
Which costs less to run per year?
By EPA estimates at 15,000 miles a year, the Porsche 718 runs about $3,150 a year in fuel at its most efficient configuration, versus about $3,300 for the Mercedes-Benz SL-Class — a difference of roughly $150 per year.
What engines do the SL-Class and 718 offer?
Mercedes-Benz SL-Class: SIDI, SIDI; Mild Hybrid, SIDI; PHEV, 6.0. Porsche 718: SIDI.
Are they in the same vehicle class?
Yes — the EPA classifies both the Mercedes-Benz SL-Class and the Porsche 718 as Two Seaters, so they compete directly.
More SL-Class comparisons
Comparison id: mercedes-benz-sl-class-vs-porsche-718