A combined 22 MPG won’t top any fuel economy charts, but for a high-performance convertible sports car like the 2017 Porsche 911 Carrera 4 GTS Cabriolet, it’s an acceptable figure. Buyers of this car usually prioritize the thrill of driving, all-weather handling, and the Porsche brand, and they are willing to pay more for gas.

City and highway performance

The EPA estimates the 2017 911 Carrera 4 GTS Cabriolet at 20 MPG in the city and 25 MPG on the highway. This difference shows how city driving, with frequent stops, reduces fuel mileage. The low city MPG implies this car isn’t ideal for stop-and-go commutes, which is expected with its performance tuning and sensitive throttle. However, highway mileage is better, showing the 3.0L turbocharged flat-six engine can cruise more efficiently at constant speeds. Most owners probably won’t be focused on fuel efficiency anyway.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2017 Porsche 911 Carrera 4 GTS Cabriolet is $2,650. This is based on 15,000 miles per year, using national average fuel prices, with 55% city and 45% highway driving. Premium fuel is needed for the engine to perform well, and its cost is included in this estimate.

Real-world expectations

The EPA provides a standard, but real-world fuel economy changes with driving style, road conditions, tire inflation, and weather. Drivers in urban areas who accelerate frequently will likely see lower numbers than the EPA estimates. A more relaxed driver, using the car for highway trips on open roads, might get slightly better fuel economy. Ultimately, this 911 model is for performance, which encourages drivers to use its capabilities.

How it compares

The 911 Carrera 4 GTS Cabriolet’s fuel economy is normal compared to other high-performance convertibles, but not the best. For instance, a similar Mercedes-AMG C63 S Cabriolet, with a more powerful V8 engine, gets around 19 MPG combined. An Audi R8 Spyder V10 gets an even lower 16 MPG combined because of its higher performance and larger engine. These comparisons show the cost for of a certain level of performance. A sports car with lower performance might have better economy. Buyers looking at these models probably know about the fuel economy compromises. For 911 MPG across all years, fuel economy numbers do not vary heavily. For all Porsche fuel economy data, this 911 model does not stand out as an especially eco-friendly car.

Tips to maximize efficiency

Avoid using the engine’s full power often. The turbocharged flat-six responds quickly, but frequent bursts of acceleration waste fuel. Drive smoothly to improve efficiency.

Keep tires inflated to the manufacturer’s specifications. Underinflated tires increase rolling resistance, making the engine work harder and consume more fuel to maintain speed.

Avoid idling for long periods. Modern engines are designed to run efficiently while moving. If stopped for more than a minute or two, turn off the engine instead of idling.

Use the car’s ‘Normal’ or ‘Eco’ driving modes, if available. These modes change the throttle and shift points to focus on fuel efficiency instead of performance.

Keep up with maintenance. A well-maintained engine and drivetrain will operate more efficiently. Regular tune-ups, air filter replacements, and following service schedules ensure the engine performs well and uses fuel efficiently.