22 MPG combined is not the primary reason someone buys the 2017 Porsche 911 Carrera GTS Cabriolet. It’s not a vehicle bought for maximizing fuel efficiency. It’s an experience, a statement, feeling the road from behind the wheel of a beautifully engineered machine. The buyer of this GTS Cabriolet prioritizes the sound of the flat-six engine, the precise steering, and the wind in their hair over saving on gas. They understand the trade-off: driving pleasure requires more frequent stops at the pump.

City and highway performance

The EPA estimates 20 MPG in the city and 26 MPG on the highway for the 2017 911 Carrera GTS Cabriolet with the automatic (PDK) transmission. These numbers depend on driving style. The city MPG can drop quickly with aggressive acceleration. A relaxed highway trip will yield numbers closer to, or even above, the EPA estimate. The turbocharged 3.0L flat-six, despite its smaller size compared to older 911s, delivers a broad powerband. Drivers do not need to downshift as often to keep momentum on the open road, which helps fuel economy and lowers stress on the engine with easy driving.

Annual fuel cost

According to the EPA, expect to spend about $2,650 per year on fuel for the 2017 Porsche 911 Carrera GTS Cabriolet. This is based on driving 15,000 miles a year, with 55% in the city and 45% on the highway, using the national average fuel price. This is a useful benchmark, but premium fuel is required, and prices change by region. Someone driving only in a busy city will likely see a higher annual fuel cost. A driver who mainly uses the car for weekend highway trips might see a lower fuel cost.

Real-world expectations

The EPA numbers provide a baseline, but expect some differences in the real world. Owners often report numbers slightly below the EPA estimate in mixed driving, particularly if they often drive aggressively to experience the car’s performance. The temptation to wind out the engine and feel the turbochargers is strong, and fighting that urge takes restraint that few GTS Cabriolet owners possess. It’s important to mix performance driving with mindful driving to see what the car can really do.

How it compares

Compared to other high-performance convertibles, the 911 GTS Cabriolet’s fuel economy is within the expected range. For example, the BMW M4 Convertible (around 23 MPG combined) offers similar performance with slightly better fuel efficiency. The Mercedes-AMG C63 S Cabriolet, with its V8, uses significantly more fuel, estimated at around 19 MPG combined. The Audi R8 Spyder also demands more fuel, delivering only 16 MPG combined. The slight differences matter to some, but the Porsche buyer is usually more focused on driving dynamics, brand prestige, and the unique 911 experience. For more information, explore all Porsche fuel economy data. If you are curious about other year’s numbers, see the 911 MPG across all years.

Tips to maximize efficiency

The most obvious tip is to avoid flooring the accelerator. Smooth inputs will make a difference. The PDK transmission selects the best gear; trust it to do its job, instead of constantly overriding it with manual shifts.

Make sure the tires are properly inflated. Low tire pressure increases rolling resistance, which affects fuel economy. Check the sticker on the driver’s side doorjamb for the recommended pressure and keep the tires inflated to that level.

Avoid carrying extra weight in the car. The GTS Cabriolet is a precise machine; extra weight hurts both performance and efficiency. Empty the trunk of items that aren’t needed on a daily basis.

Plan routes to avoid stop-and-go traffic. Accelerating and braking uses more fuel than maintaining a steady speed. Check traffic conditions before leaving and consider other routes if possible.

Limit use of the air conditioning. While essential on hot days, the air conditioning compressor puts a load on the engine, consuming more fuel. Open the top whenever possible to enjoy the open air and reduce A/C use.