24 MPG combined is adequate, but not stellar, for the 2018 Porsche Cayman S 2.5L. This isn’t a family-friendly SUV or a hybrid commuter car. It’s a precision-engineered sports car designed for driving enjoyment. The fuel economy is simply what you pay for Porsche performance. The buyer considering this Cayman isn’t primarily focused on using less gas, they’re seeking a thrilling driving experience, and the fuel consumption reflects that.

City and highway performance

The EPA estimates suggest 21 MPG in city driving and 28 MPG on the highway. The city figure is arguably more relevant to the typical Cayman S owner. This car isn’t purchased for cross-country road trips. It tends to be used for shorter, spirited drives, weekend jaunts, and occasional track days. Stop-and-go traffic certainly takes its toll, but even in city environments, the easily accessible power of the turbocharged 2.5-liter engine encourages aggressive acceleration, further impacting fuel consumption. The highway number is achievable, but only if you consciously restrain yourself. Considering the temptation to exploit the Cayman S’s capabilities on open roads, expecting to consistently meet that 28 MPG figure is optimistic.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,400 for the 2018 Porsche Cayman S, based on driving 15,000 miles per year using national average fuel prices at the time of calculation. This figure provides a reasonable benchmark, but actual costs will vary significantly depending on individual driving habits, local fuel prices (premium fuel is required), and the number of miles driven. Someone who primarily uses their Cayman S for weekend drives will likely spend less, while someone who commutes daily in heavy traffic will likely spend more.

Real-world expectations

Don’t consider the EPA numbers as definite. Real-world fuel economy for the 2018 Cayman S 2.5L will almost certainly be lower than advertised, especially if you drive it the way Porsche intended. Expect something closer to 19-22 MPG in mixed driving conditions. Aggressive driving, frequent short trips, and extensive idling will further decrease fuel efficiency. Those who track their cars regularly may see even lower figures. However, even with enthusiastic driving, reaching the EPA combined estimate is possible with conscious effort.

How it compares

Compared to other sports cars, the 2018 Cayman S occupies a middle ground in terms of fuel economy. The BMW M2 boasts similar performance but achieves slightly better gas mileage, around 20 MPG city and 26 MPG highway. The Nissan 370Z, with its larger V6 engine, typically returns worse figures, closer to 18 MPG city and 25 MPG highway. The Alpine A110, a closer performance rival made by Renault, will outpace the Cayman S in fuel economy due to its smaller engine and lower curb weight. Fuel economy is rarely the main reason to buy a sports car, these differences often become a secondary consideration for shoppers. For all Porsche fuel economy data, you can visit this page. Plus, you can view the CAYMAN MPG across all years.

Tips to maximize efficiency

Resist the urge to constantly exploit the engine’s power. The 2.5-liter turbo is eager to deliver instant acceleration, but every hard launch and aggressive overtake uses more fuel. Smooth, deliberate acceleration and maintaining a steady speed will significantly improve your MPG.

Pay attention to tire pressures. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressures regularly and maintain them at the manufacturer’s recommended levels to optimize efficiency and handling.

Minimize idling. Allowing the engine to idle for extended periods, especially during warm-up, wastes fuel. If you’re stopped for more than a minute, switch off the engine to conserve gas. Modern engines don’t require extended warm-up periods; gentle driving is sufficient to bring the engine up to operating temperature.

Use the automatic transmission’s Eco mode, if available. While it might slightly dull throttle response and shift points, it optimizes the transmission for fuel efficiency, encouraging earlier upshifts and later downshifts. For ultimate control, use manual mode with the paddle shifters and stay in higher gears.