22 MPG combined won’t win any green awards, but it’s what you get with a 2015 Porsche 911 Carrera 4 Cabriolet. People buy this car for reasons other than saving gas, or to make a political statement. It’s a lifestyle choice, a reward, and a way to express yourself. Fuel consumption probably isn’t the biggest concern for someone who wants all-weather grip, open-top driving, and the sound of a naturally aspirated flat-six engine.

City and highway performance

The EPA estimates 20 MPG in the city and 27 MPG on the highway for this all-wheel-drive convertible. These figures are possible because of the 3.4L engine and Porsche’s 7-speed dual-clutch automatic (AM-S7) transmission. The city number reflects stop-and-go driving, where the 911’s small engine and efficient transmission can’t fully compensate for its weight and sporty design. However, the highway number is surprisingly good. If you drive gently on long trips, this 911 can get reasonable fuel economy, making it a surprisingly capable grand tourer.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 Porsche 911 Carrera 4 Cabriolet at $2,650. This is based on driving 15,000 miles per year and using national average fuel prices for premium unleaded gasoline, which this Porsche requires. Your actual fuel cost can change based on your driving habits and local gas prices. Driving hard, taking frequent short trips, and living in an area with high gas prices will all increase your annual fuel spending.

Real-world expectations

The EPA figures are a good starting point, but real-world fuel economy can change a lot based on how and where you drive. Owners who drive mostly in the city or enjoy fast weekend drives might see numbers closer to the 20 MPG city rating, or even a little lower. On the other hand, drivers who focus on saving fuel and spend a lot of time on the highway might be able to get more than the 27 MPG highway rating. Expect about 18 MPG to 30 MPG as your typical range. The 911 is fun to drive fast, and many drivers will do that as much as possible, and that burns gas.

How it compares

The 2015 911 Carrera 4 Cabriolet compares well to other high-performance convertibles. A similar BMW M4 Convertible from the same year gets around 19 MPG combined. The Mercedes-AMG C63 S Cabriolet, which has a powerful V8 engine, gets an EPA-estimated 18 MPG combined. They all offer similar performance and luxury, but the Porsche doesn’t burn as much gas. Even compared to all Porsche fuel economy data, the Carrera 4 Cabriolet balances performance and efficiency. Other 911 versions, especially those with bigger engines or turbochargers, often use more fuel to make more power. For example, the 911 Turbo S from the same year gets a combined 20 MPG. If you’re comparing models within the 911 lineup, you should compare 911 MPG across all years so you can see how model year and trim changes affect how much gas they use.

Tips to maximize efficiency

Driving smoothly and steadily is important for getting good fuel economy in any car, including the 911. Avoid accelerating and braking hard, because those actions use a lot of fuel. Use the Porsche’s “coasting” function when you can, which disconnects the engine when coasting downhill or stopping.

Keep your tires properly inflated. Under-inflated tires increase rolling resistance and reduce fuel economy. Check your tire pressures often and inflate them to the manufacturer’s recommended levels. You can find those levels on the driver’s side doorjamb.

Remove extra weight from the car. Taking items out of the trunk and passenger area can improve fuel economy, especially in the city. Extra weight makes the engine work harder.

Use the air conditioning less when possible. The air conditioning compressor puts a load on the engine, which uses more fuel. When the weather is nice, open the windows or use the ventilation system.

Plan your routes to avoid traffic. Stop-and-go traffic uses a lot of gas. Use navigation apps to find and avoid traffic jams, particularly during rush hour.