22 MPG combined is not why anyone buys a 2018 Porsche 911 Carrera GTS Cabriolet. That Porsche can deliver a car this thrilling, this visceral, and this capable while still achieving mileage in line with a modern family sedan shows great engineering. This isn’t a car for penny-pinchers; it’s for enthusiasts who prioritize open-air exhilaration and precision performance, accepting the fuel bill as the cost of admission to an exclusive club.

City and highway performance

The 911 Carrera GTS Cabriolet achieves 20 MPG in the city and 26 MPG on the highway, according to EPA estimates. The city figure reflects the constant stop-and-go common to urban driving, where the twin-turbocharged 3.0-liter flat-six works harder to overcome inertia. The highway number showcases the engine’s efficiency at sustained speeds, particularly when the seven-speed PDK automatic transmission (AM-S7) is allowed to settle into its higher gears. The difference illustrates that this car, while certainly capable of daily driving, truly shines on open roads where its performance capabilities can be fully exploited.

Annual fuel cost

Owning a performance car inevitably means higher running costs, and fuel is a significant part of that equation. The EPA estimates an annual fuel cost of $2,650 for the 2018 Porsche 911 Carrera GTS Cabriolet. This figure is based on driving 15,000 miles per year, with a mix of city and highway driving, using the national average fuel price for premium gasoline. Remember that individual driving habits and fluctuations in gasoline prices can significantly impact this number. Aggressive driving, for example, will certainly decrease fuel economy and increase the annual cost. This data complements all Porsche fuel economy data.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy often varies. Drivers of the 911 Carrera GTS Cabriolet are likely to see figures that fluctuate depending on their driving style and environment. Consistent use of the Sport or Sport Plus modes, with their more aggressive throttle mapping and lower gear holding, will invariably lead to lower MPG. Conversely, those prioritizing efficiency and employing a more relaxed driving style may find they slightly exceed the EPA estimates, particularly on long highway journeys. Consider these conditions in relation to the 911 MPG across all years.

How it compares

Compared to other high-performance convertibles, the 2018 911 Carrera GTS Cabriolet occupies a nuanced position. The BMW M4 Convertible, for instance, manages around 19 MPG combined with its inline-six. The Mercedes-AMG C63 S Cabriolet, with its V8 engine, typically returns even lower figures, often hovering around 18 MPG combined. Even within the Porsche family, the more powerful 911 Turbo S Cabriolet sacrifices some efficiency for its increased performance, achieving around 20 MPG combined. The GTS strikes a balance, offering a significant performance upgrade over the base 911 while maintaining a relatively similar fuel economy profile. For drivers seeking an engaging experience without completely disregarding fuel consumption, this is a good option. However, the Audi R8 Spyder, despite its larger engine, can achieve around 16 MPG combined due to factors like its lightweight construction.

Tips to maximize efficiency

While the 911 GTS Cabriolet is primarily about performance, some strategies can help optimize fuel efficiency without sacrificing too much driving enjoyment. Avoiding excessive idling, particularly when the engine is cold, can prevent unnecessary fuel consumption. Modern engines warm up quickly, so prolonged idling is generally counterproductive.

Gentle acceleration and anticipation of traffic flow are also critical. Smooth, progressive inputs on the throttle minimize the strain on the engine, leading to better fuel economy. Looking ahead and anticipating braking points allows for more gradual deceleration, reducing the need for harsh braking and subsequent acceleration.

Proper tire inflation is another often-overlooked factor. Underinflated tires increase rolling resistance, forcing the engine to work harder. Regularly check and maintain the recommended tire pressure, which can be found on the driver’s side doorjamb.

Use the PDK transmission’s automatic mode in everyday driving. While the manual mode offers enhanced control, the automatic mode is programmed to select the most efficient gear for the given conditions, optimizing fuel economy. Switching to manual mode mainly for spirited drives can noticeably improve results.

Consider using Porsche’s “coasting” function when the transmission allows. This disengages the engine from the drivetrain when you lift off the accelerator, allowing the car to coast freely and save fuel. While subtle, this feature can contribute to incremental improvements over time.