2020 head-to-head · Two-Seater

2020 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.

Swap sides
✓ Cheaper to run
$2,693/ year to fuel
22 MPG
✓ Cheaper to run
$2,469/ year to fuel
24 MPG

The 2020 Porsche Cayman is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,469 a year to fuel (24 MPG), versus $2,693 for the 2020 Mercedes-Benz SL-Class (22 MPG). That's roughly $224 a year, or about $1,122 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-ClassPorsche Cayman
$2,693 Your annual fuel cost $2,469
22 MPG Combined efficiency 24 MPG
20 MPG City 21 MPG
28 MPG Highway 27 MPG
395 g/mi Tailpipe CO₂ (g/mi) 375 g/mi
4/10 EPA fuel economy score 5/10
4/10 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 39 2020 two-seaters, the Mercedes-Benz SL-Class ranks 11th and the Porsche Cayman 10th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2020 Mercedes-Benz SL-Class or the 2020 Porsche Cayman?

Measured by cost to drive, the Porsche Cayman. The Mercedes-Benz SL-Class is rated 22 MPG combined and the Porsche Cayman 24 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2020 Mercedes-Benz SL-Class vs. the Porsche Cayman per year?

At 15,000 miles a year with $3.95/gal premium gas, about $2,693 for the Mercedes-Benz SL-Class and $2,469 for the Porsche Cayman.

Mercedes-Benz SL-Class vs Porsche Cayman in other years

More 2020 comparisons

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