Porsche 718 Cayman GTS
20 MPG The 2025 Porsche 718 Cayman GTS is EPA-rated at 20 MPG combined (18 city / 24 highway). Over 15,000 miles a year that is about 750 gallons, $2400 a year in fuel, or $0.160 per mile at $3.20/gal.
Across its full 2021–2025 run it averages 20 MPG, essentially flat across 5 model years.
Running cost at different fuel prices and mileages
The figure everyone actually wants, and the one the EPA does not publish — because it depends on a fuel price no agency will commit to.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.125 | $1250 | $1875 | $2500 |
| $3.00/gal | $0.150 | $1500 | $2250 | $3000 |
| $3.20/gal | $0.160 | $1600 | $2400 | $3200 |
| $3.50/gal | $0.175 | $1750 | $2625 | $3500 |
| $4.00/gal | $0.200 | $2000 | $3000 | $4000 |
| $4.50/gal | $0.225 | $2250 | $3375 | $4500 |
| $5.00/gal | $0.250 | $2500 | $3750 | $5000 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2025 | 20 MPG | 18 | 24 | $3850 | 438 | 2 |
| 2024 | 20 MPG | 18 | 24 | $3850 | 438 | 2 |
| 2023 | 20 MPG | 18 | 24 | $3850 | 438 | 2 |
| 2022 | 20 MPG | 18 | 24 | $3850 | 438 | 2 |
| 2021 | 20 MPG | 18 | 24 | $3850 | 438 | 2 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
How it compares in its class
Among the 105 two seaters models tracked here, the Porsche 718 Cayman GTS ranks 46 on current figures, against a class average of 21.4 MPG.
Closest more-efficient alternatives in the same class: Acura NSX Hybrid (21), Honda S2000 (21), Jaguar F-Type S AWD Convertible (21), Jaguar F-Type S AWD Coupe (21), Mercedes-Benz SLK230 Kompressor (21).
Tailpipe CO₂ is rated at 438 grams per mile, which works out to roughly 6.6 tonnes a year at 15,000 miles.
Questions
What MPG does the Porsche 718 Cayman GTS get?
The 2025 Porsche 718 Cayman GTS is rated at 20 MPG combined by the EPA — 18 city and 24 highway. Across all 5 model years in the database it averages 20 MPG, ranging from 19 to 21 depending on year and trim.
How much does a Porsche 718 Cayman GTS cost in fuel per year?
At 20 MPG and 15,000 miles a year, it burns about 750 gallons — roughly $2400 a year with fuel at $3.20 a gallon, or $0.160 per mile. The EPA's own published annual figure for the 2025 model is $3850.
Has the Porsche 718 Cayman GTS become more efficient over time?
Barely. It sits at 20 MPG today against 20 in 2021 — essentially flat across 5 model years, with efficiency gains offset by weight and power creep.
Is the Porsche 718 Cayman GTS efficient for its class?
It ranks 46 of 105 in the Two Seaters class on current figures, against a class average of 21.4 MPG. That is 1.4 worse than typical for the class.
EPA test figures from fueleconomy.gov. Cost per mile and annual fuel spend are computed at a reference price of $3.20 per gallon — use your own price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.