Against 422 other 4-cyl cars rated 2023–2025, the 718 Cayman trails their 26.5 mpg average by 4 mpg, about $258 a year. Averaged over the years each was sold, the most economical engine since 2020, the 2L 4-cyl (2021–2025), does 24 mpg and the thirstiest, the 4L 6-cyl (2020–2025), 20.7: $255 a year apart.
Every Porsche 718 Cayman engine, compared
Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 2L 4-cyl | 21 / 27 | 2021–2025 | $1,600 | |
| 4L 6-cyl | 18.5 / 23.8 | 2020–2025 | $1,855 |
What that actually costs
Against its rivals in the same model years, the Mercedes-Benz AMG GT gets 19.3 mpg and the Aston Martin Vantage 18 mpg, next to 22.5 mpg for the 2025 718 Cayman. The 718 Cayman is the cheapest of them to run: $426 a year less than the Aston Martin Vantage.
| Measure | Value |
|---|---|
| Cost per mile (2025) | $0.142 |
| Fuel per year | $1,707 |
| Fuel over five years | $8,535 |
| Against other 4-cyl cars, 2023–2025 | +$258 a year |
| EPA's own estimate | $3,482 a year |
City or highway — who is this car for
The 2025 Porsche 718 Cayman gives up 5.5 mpg in town: 25.5 on the highway against 20 in the city, $414 a year if every mile were city driving.
| Measure | Value | Reading |
|---|---|---|
| City (2025) | 20 mpg | $1,920 a year if you only drive in town |
| Highway | 25.5 mpg | $1,506 a year if you mostly commute |
| Gap | +5.5 mpg (28%) | Typical for its type |
How the 718 Cayman changed over the years
The 718 Cayman peaked in 2025 at 22.5 mpg (20 city, 25.5 highway) and was at its thirstiest in 2020 at 19 — 3.5 mpg apart, or $314 a year in fuel between buying one year and the other. The biggest single-year change came in 2021: 19 to 22.5 mpg.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2025 | 20 / 25.5 | 2 | $1,707 | |
| 2024 | 20 / 25.5 | 2 | $1,707 | |
| 2023 | 20 / 25.5 | 2 | $1,707 | |
| 2022 | 20 / 25.5 | 2 | $1,707 | |
| 2021 | 20 / 25.5 | 2 | $1,707 | |
| 2020 | 16 / 23 | 1 | $2,021 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 11 EPA ratings of the Porsche 718 Cayman — 2 engines across 2020–2025. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $3,482. Full method.
Frequently asked questions
What mpg does the 2025 Porsche 718 Cayman get?
22.5 mpg combined, 20 city and 25.5 highway, per EPA; its 2 versions that year range from 21 to 24. Across every year since 2020 the 718 Cayman has averaged 22.2 mpg.
Is the 2025 718 Cayman more efficient than the 2024?
About the same: 22.5 against 22.5 mpg combined.
Which 718 Cayman year has the best gas mileage?
The 2025, at 22.5 mpg combined (20 city, 25.5 highway), which is also the latest model year we hold.
Does the 718 Cayman get better gas mileage than the Mercedes-Benz AMG GT?
Yes: 22.5 mpg for the 2025 718 Cayman against 19.3 for the 2026 Mercedes-Benz AMG GT, about $283 a year less to run.
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