FuelFacts

2018 Porsche Cayman MPG & Specs — Real-World vs EPA, All Trims

Every gas trim of this model takes premium.

24–25
MPG combined (21–22 city / 28–29 hwy)
$2,808–$2,925
est. fuel / year (today's prices, 15k mi)
Premium
gas type

Is the 2018 Porsche Cayman good on gas?

At up to 25 MPG combined, the 2018 Porsche Cayman is better than average for a Two Seaters — that class averages about 19.4 MPG across 2,500 EPA-tested versions, so it's a good pick on fuel for its size.

Real-world MPG vs the EPA number

The EPA figures above come from a standardized dynamometer test, not the open road — real-world MPG typically runs a bit lower depending on your driving, climate and terrain. That's true of every car on this site, old or new.

At today's AAA national average price — $4.68/gal for premium gas as of 2026-07-05 — the most efficient trim runs about $2,808/year (roughly $234/month, about $18.72 per 100 miles) at the EPA's assumed 15,000 miles/year, using an estimated 600 gallons a year. We don't estimate a cost-per-fill since exact tank size isn't in the public EPA dataset, but the per-100-mile figure scales to any tank. Current national average gas prices →

2018 Porsche Cayman trims & fuel economy

Trim (engine / transmission)FuelMPGFuel/yr (today's price)
2.0L 4-cyl, AM-S7 automatic, RWDPREMIUM25$2,808
2.0L 4-cyl, 6-spd manual, RWDPREMIUM24$2,925
Where the EPA lists premium, that’s the fuel the maker specified for the mileage test — many such engines run on regular with slightly less power/MPG. Whether premium is required or just recommended is an owner’s-manual detail the EPA dataset omits, so we don’t guess it.

2018 Porsche Cayman specs

What the EPA test-car listings record for this model year — every combination sold is a row in the trims table above.

Engine options2.0L 4-cyl turbo
TransmissionAM-S7 automatic · 6-spd manual
Drive typeRWD
EPA body classTwo Seaters
FuelPremium
Tailpipe CO₂353–369 g/mi

Other years of the Porsche Cayman

2020 Porsche Cayman2019 Porsche Cayman2017 Porsche Cayman2016 Porsche Cayman2015 Porsche Cayman2014 Porsche Cayman2012 Porsche Cayman2011 Porsche Cayman

Similar cars (Two Seaters)

2018 smart fortwo electric drive coupe2018 smart fortwo electric drive convertible2018 BMW M4 DTM Champions Edition2018 McLaren Automotive 540C Coupe2018 Audi R8 RWD2018 RUF Automobile RUF TURBO 12/CTR3

Cars that take premium · Cheapest cars to fuel · Where fuel grade depends on the trim · Fuel guides

2 trim(s) · EPA FuelEconomy.gov data retrieved 2026-07-24 · fuel prices AAA national average as of 2026-07-05.