16 MPG combined isn’t just a number for the 2025 Porsche 911 Turbo S Cabriolet 3.7L 6-cyl, it’s a mere footnote in a symphony of raw power, engineering precision, and unfiltered sensory assault. This machine isn’t built for efficiency, it’s built to dominate, to thrill, to redefine what a convertible supercar can be. Owners of the Turbo S Cabriolet don’t pick it for its fuel economy, nor do they even consider it a relevant metric in their decision-making process. They buy it for the instantaneous, neck-snapping acceleration, the visceral sound of the twin-turbo flat-six, and the unapologetic statement it makes about their passion for driving at the absolute limit. Fuel consumption, for them, is simply the cost of admission to an exclusive club where performance reigns supreme, and the open sky is just another canvas for speed.

City and highway performance

The 2025 911 Turbo S Cabriolet registers 14 MPG in city driving and 20 MPG on the highway. These figures reflect the inherent compromises of a high-performance, all-wheel-drive powertrain, particularly one designed to deliver 640 horsepower and 590 lb-ft of torque. In urban environments, stop-and-go traffic and frequent acceleration events inevitably depress efficiency. The 8-speed Porsche Doppelkupplung (PDK) automatic transmission, while incredibly quick and smooth, still operates within the physical constraints of moving over 3,700 pounds of meticulously engineered German metal. On the open highway, where the engine can settle into a more relaxed rhythm, the efficiency improves, but even here, the massive power reserves mean that any prod of the accelerator will trigger a dramatic surge of fuel consumption. Owners understand this, they know that the exhilaration of watching the speedometer needle sweep towards triple digits is directly proportional to how quickly the fuel gauge moves in the opposite direction. It’s a trade-off they willingly accept, and frankly, expect.

Annual fuel cost

The Environmental Protection Agency (EPA) estimates the annual fuel cost for the 2025 Porsche 911 Turbo S Cabriolet at $3,600 per year. This figure is based on an assumed 15,000 miles driven annually, with a representative blend of city and highway driving, and national average fuel prices for premium gasoline. For prospective buyers, this $3,600 figure is unlikely to be a deciding factor. Someone considering a vehicle with a starting price well north of $220,000 typically views fuel as an operating expense, not a cost to be optimized. The annual outlay for premium fuel is a drop in the bucket compared to insurance, maintenance, and certainly the depreciation of such an exquisite machine. It’s part of the ownership cost, and for the enthusiast, it’s a small price to pay for the unparalleled driving experience. Those genuinely concerned with annual fuel expenditure are simply not the target demographic for this particular 911 Turbo S Cabriolet.

Real-world expectations

Real-world fuel economy for the 2025 Porsche 911 Turbo S Cabriolet can vary wildly, often influenced more by the driver’s intent than by external conditions. Those who frequently exploit the engine’s immense capabilities, engaging in aggressive acceleration runs, track days, or spirited canyon carving, will undoubtedly see figures well below the EPA estimates. Conversely, a driver making a conscientious effort to drive leisurely on the highway might even observe numbers slightly higher than the 20 MPG rating. However, such restraint in a Turbo S seems almost sacrilegious. The car is an invitation to exceed limits, and its fuel consumption reflects that. It’s safe to assume that most owners will experience fuel economy hovering around the combined 16 MPG figure, often trending closer to the city rating due to the irresistible urge to access that explosive power. The Turbo S is an automotive addiction, and part of that addiction involves frequent visits to the fuel pump. For more information on all Porsche fuel economy data, including other high-performance models, you can explore our extensive database.

How it compares

When placed against its direct rivals, the 2025 Porsche 911 Turbo S Cabriolet’s fuel economy remains distinctly within the expected range for its class of ultra-high-performance sports cars. For instance, a comparable Lamborghini Huracan Tecnica, with its naturally aspirated V10, typically clocks in at 13 MPG combined, 11 city, and 18 highway. Similarly, the Ferrari 296 GTS, a plug-in hybrid supercar, manages 18 MPG combined, 16 city, and 20 highway on gasoline power, though its electric range adds a different dimension to efficiency. Even within the 911 family itself, a standard Carrera S Cabriolet (3.0L twin-turbo flat-six) achieves a more modest 20 MPG combined, 18 city, 24 highway. The buyer of a 911 Turbo S Cabriolet understands that the extra power, all-wheel-drive traction, and superior technological prowess come with a slight, but acceptable, penalty at the pump compared to some competitors. The comparison isn’t about saving money, it’s about understanding the engineering priorities of each marque. For a complete look at 911 MPG across all years, our archives provide detailed information on efficiency throughout the model’s lineage.

Tips to maximize efficiency

While the goal of maximizing efficiency in a 911 Turbo S Cabriolet might seem counterintuitive, there are still ways to nudge those MPG figures upward, however slightly. Smooth and gradual acceleration is perhaps the most significant factor. Avoiding sudden, heavy throttle inputs, which instantly summon peak boost and fuel flow, will make a tangible difference.

Anticipating traffic and road conditions can also significantly improve fuel economy. Gentle braking rather than abrupt stops, and maintaining momentum where possible, reduces the energy wasted through deceleration and subsequent re-acceleration. Activating cruise control on suitable highway stretches allows the engine and transmission to operate in their most efficient range for extended periods.

Ensuring proper tire inflation is a simple but effective measure. Underinflated tires increase rolling resistance, forcing the engine to work harder. Adhering to Porsche’s recommended tire pressures provides both optimal efficiency and the intended handling characteristics.

Using the car’s various driving modes can also contribute. While Sport and Sport Plus are intoxicating, selecting Normal mode for everyday commuting or cruising prioritizes comfort and, by extension, slightly better efficiency, by altering throttle response, transmission shift points, and suspension settings to be less aggressive.

Finally, minimizing unnecessary weight in the trunk or frunk, though often negligible in such a powerful car, can theoretically help. Every little bit of extra mass the engine needs to propel requires more fuel, particularly when accelerating. While these adjustments won’t transform the Turbo S Cabriolet into a frugal commuter, they can help mitigate some of the inherent thirst of this magnificent machine during less spirited drives.