24 MPG combined isn’t exactly efficient, but for the 2015 Porsche Boxster S, it’s a reasonable tradeoff for the performance and driving experience. People buy this car not for its fuel sipping, but for its mid-engine balance, sharp handling, and the flat-six engine’s glorious sound. The Boxster S buyer prioritizes driving pleasure and accepts the fuel bill.

City and highway performance

The 2015 Boxster S with the 3.4L flat-six and seven-speed dual-clutch automatic (PDK) gets an EPA-estimated 21 MPG in the city and 29 MPG on the highway. That highway figure is respectable for a performance car and achievable on longer trips if you don’t push the throttle too hard. In urban environments, the Boxster S’s sporty nature, along with stop-and-go traffic, tends to bring that city MPG closer to the low end of the estimate. Hard acceleration and frequent gear changes will hurt fuel consumption.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 Porsche Boxster S to be $2,400. This is based on driving 15,000 miles per year and using the national average fuel price for premium gasoline, which the Boxster S requires. Your actual costs may vary depending on your driving, local fuel prices, and how many miles you drive.

Real-world expectations

The EPA numbers offer a benchmark, but real-world fuel economy for the 2015 Boxster S can change a lot depending on driving style and conditions. Drivers who often use the engine’s full performance will likely see figures closer to the low 20s in combined driving. Drivers who prioritize fuel efficiency and drive more gently might get numbers closer to, or even slightly above, the EPA estimates. Track days and canyon runs will drop MPG figures.

How it compares

Compared to other sporty roadsters, the 2015 Boxster S is in the middle for fuel efficiency. The BMW Z4 sDrive35i, with its turbocharged inline-six, gets roughly similar numbers, around 20 MPG city and 28 MPG highway. The Mercedes-Benz SLK350, with its V6, is also in the same range. A Jaguar F-Type V6, with its supercharged engine, tends to use more gas, falling closer to 19 MPG combined. Comparing the Boxster S to a sports car like the Mazda MX-5 Miata (around 29 MPG combined) shows the trade-off between performance and fuel efficiency in the roadster class. The MX-5 Miata’s best-in-class numbers would be better for drivers concerned with fuel costs. See all all Porsche fuel economy data. Also, check the BOXSTER MPG across all years.

Tips to maximize efficiency

The PDK transmission helps maximize fuel efficiency. In normal driving, let it shift early and keep the engine in the most efficient part of its powerband. Avoid hard acceleration unless needed, and use the paddles to manually upshift if you need more power for passing or merging.

Check your tire pressure regularly. Properly inflated tires reduce rolling resistance, which can improve fuel economy. See the sticker on the driver’s side doorjamb for the recommended tire pressure for your Boxster S.

Don’t idle. If you’re stopped for more than a minute or two, turn off the engine. Modern cars restart quickly, and avoiding idling can save fuel.

Plan your routes. Avoid congested areas and routes with stop-and-go traffic when possible. Smoother driving means better fuel economy. Consider using the navigation system to find the best route.