24 MPG combined hardly qualifies the 2018 Porsche Boxster S as a fuel-sipping champion. But for the enthusiast who demands a mid-engine sports car capable of delivering both exhilarating performance and an open-air driving experience, that figure becomes far more palatable. The 2.5L turbocharged flat-four engine prioritizes responsiveness and a sonorous soundtrack over ultimate efficiency, and frankly, Boxster S buyers have typically made peace with that compromise long before signing on the dotted line.

City and highway performance

The EPA estimates rate the 2018 Boxster S at 21 MPG in the city and 28 MPG on the highway. The disparity is less dramatic than some might expect, the engine’s relatively flat torque curve and the effectiveness of the seven-speed dual-clutch automatic transmission (PDK) optimize fuel consumption even during stop-and-go traffic. The highway number, while not outstanding, is respectable enough to make longer road trips a financially tolerable affair, assuming the limited luggage space can accommodate your needs. Remember that those estimates were produced under controlled conditions. An aggressive driving style, which the Boxster S actively encourages, will undoubtedly lead to lower real-world numbers in both environments.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2018 Porsche Boxster S at precisely $2,400. This figure is based on driving 15,000 miles per year, with a fuel price reflecting national averages. It’s important to recognize that this is merely an estimate, and your actual fuel expenses may vary depending on your driving habits, the prevailing fuel prices in your area, and the specific grade of gasoline you choose. Because of this car’s turbocharged performance, filling with premium fuel (as recommended) will significantly increase this annual expense.

Real-world expectations

While the EPA provides a benchmark, real-world fuel economy for the 2018 Boxster S tends to hover in the low 20s for most owners. Expect anywhere from 18 MPG in the city with a heavy foot to around 26 MPG on long highway cruises at legal speeds. Those who frequently engage the Sport or Sport Plus driving modes, or who participate in track days, should prepare for numbers even lower. The Boxster S doesn’t penalize you *too* severely in mixed driving, but its thirst is undeniable, and regular trips to the gas station are part of the ownership experience. See all all Porsche fuel economy data here.

How it compares

Compared to its rivals, the 2018 Boxster S occupies a middle ground. The Alfa Romeo 4C Spider, while offering comparable performance, achieves slightly better fuel economy at 28 MPG combined, largely due to its significantly lighter weight. On the other hand, the Jaguar F-TYPE Convertible with the supercharged V6 engine posts a combined MPG in the high teens. Even the more powerful flat-six-cylinder Boxster GTS, achieving 22 MPG, doesn’t vary much in comparison, a possible indicator of diminishing returns in the pursuit of efficiency. The BMW Z4 M40i gets around 25 MPG combined, offering similar performance with more restrained styling. The Boxster S buyer often prioritizes the unique driving experience, pedigree, and aesthetics of the Porsche brand, mitigating any concerns about a slight fuel economy disadvantage. Consult the BOXSTER MPG across all years here.

Tips to maximize efficiency

Resist the urge to constantly exploit the engine’s power. The turbocharger responds instantly to throttle inputs, and each burst of acceleration consumes additional fuel. Smooth, deliberate acceleration will significantly improve your MPG, particularly in city driving.

Take advantage of the car’s driving modes. The “Normal” mode optimizes fuel efficiency by prioritizing higher gears and less aggressive throttle mapping. It’s perfectly suitable for everyday commuting and relaxed cruising, saving the more performance-oriented modes for spirited drives.

Maintain proper tire inflation. Under-inflated tires increase rolling resistance, forcing the engine to work harder and consuming more fuel. Check your tire pressures regularly and inflate them to the recommended levels specified on the doorjamb sticker.

Minimize idling. Modern engines consume fuel even when stationary. If you’re stopped for more than a minute or two, consider turning off the engine to conserve fuel, but remember that this applies more to older cars than modern ones as starting a car also uses fuel.

Planning routes may seem minor, but avoiding low-average-speed routes can make a difference. Stop-and-go situations make fuel economy numbers drop quickly, which many Boxster S enthusiasts in particular won’t find appealing.