The Porsche 718 Cayman does 22.2 mpg combined (19.6 city, 25.3 highway), which works out to about $1,730 a year in fuel at $3.20 a gallon and 12,000 miles. Engine choice matters more than you'd think: 2L 4-cyl does 24 mpg while 4L 6-cyl does 20.7 — a difference of $255 a year. Against other V6 cars it sits above the average of 19.9 mpg.
Every Porsche 718 Cayman engine, compared
Gas mileage on the Porsche 718 Cayman ranges from 24 down to 20.7 depending on which engine sits under the bonnet — a spread of $255 a year across 2 versions of the same car. Picking the right one often saves more fuel than picking a different car altogether. 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
The Porsche 718 Cayman burns a gallon every 22.2 miles, so 12,000 miles takes about 541 gallons a year. At $3.20 that is what the table below adds up to.
| Measure | Value |
|---|---|
| Cost per mile | $0.144 |
| Fuel per year | $1,730 |
| Fuel over five years | $8,650 |
| Against other V6 cars | −$200 a year |
| EPA's own estimate | $3,482 a year |
City or highway — who is this car for
The Porsche 718 Cayman gives up 5.7 mpg the moment you leave the motorway — 25.3 out there against 19.6 in town, a 29% drop worth $441 a year. A wide gap punishes stop-and-start traffic; a narrow one means the car doesn't care where you drive it.
| Measure | Value | Reading |
|---|---|---|
| City | 19.6 mpg | $1,959 a year if you only drive in town |
| Highway | 25.3 mpg | $1,518 a year if you mostly commute |
| Gap | +5.7 mpg (29%) | 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 2025 car does 22.5. Jumps usually mark a new generation or a new engine; dips often mean a heavier body or added all-wheel drive.
| 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 Porsche 718 Cayman get?
22.2 mpg combined on average — 19.6 in the city and 25.3 on the highway, per EPA ratings across 2020–2025.
How much does a Porsche 718 Cayman cost in fuel per year?
About $1,730 at 12,000 miles and $3.20 a gallon — roughly $8,650 over five years, or 0.144 dollars a mile.
Which 718 Cayman engine is the most economical?
The 2L 4-cyl at 24 mpg, against 20.7 for the 4L 6-cyl — a difference of about $255 a year.
Is the 718 Cayman good on fuel compared with similar cars?
Against other V6 cars it sits above the average of 19.9 mpg, computed across 4940 ratings.
Are these real-world 718 Cayman figures?
No — they are EPA laboratory ratings, the same ones printed on the window sticker, and EPA's own annual fuel estimate for the Porsche 718 Cayman is $3,482 against the $1,730 we compute at 12,000 miles. Expect a little worse in practice: the spread between the 24 and 19 mpg versions of this car is smaller than the spread between two drivers of the same one.
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