19 MPG combined for the 2025 Porsche 911 Carrera GTS Cabriolet 3.6L 6-cyl tells a precise story: this isn’t a vehicle focused on miserly fuel consumption, nor is it a gas-guzzling brute. It represents the inherent trade-off of a high-performance, open-top sports car designed for driving engagement above all else. This 911 GTS, with its subtly widened body, potent new powertrain featuring a novel electric turbocharger, and track-honed chassis, is engineered to thrill, to carve corners with surgical precision, and to deliver an intoxicating soundtrack. The clientele for this particular variant understands that its mission is to deliver an unparalleled driving experience for spirited weekend runs, epic road trips, and the occasional track day. This car is not made to achieve Prius-levels of efficiency. The 19 MPG is simply part of the cost of admission to one of the most rewarding automotive experiences available today.

City and highway performance

Diving into the specifics, the EPA rates the 2025 911 Carrera GTS Cabriolet at 17 MPG in the city and 23 MPG on the highway. The city figure, 17 MPG, is precisely what one would expect from a turbocharged flat-six engine pushing nearly 500 horsepower through an advanced eight-speed automatic transmission (AM-S8) in stop-and-go traffic. This isn’t a powertrain designed for leisurely commutes; it’s always ready to unleash its considerable torque with a flex of the right foot. Frequent acceleration and deceleration cycles, coupled with the inherent energy demands of a performance powerplant, naturally depress efficiency. On the open road, the 23 MPG highway rating is a respectable achievement, particularly when considering the car’s capability to devour miles at high speed. The AM-S8 transmission plays a crucial role here, with its intelligent gear spacing and ability to keep the engine spinning at optimal, fuel-efficient RPMs during sustained cruising. The aerodynamic profile of the 911, refined over decades, also contributes to this highway efficiency, minimizing drag at cruising speeds. Still, holding a steady 70 mph on a flat highway is a different experience than a mountain pass attack, where the engine will be working significantly harder and consuming more fuel.

Annual fuel cost

The EPA provides an annual fuel cost estimate of $3,050 for the 2025 Porsche 911 Carrera GTS Cabriolet. This figure is calculated based on consuming 15,000 miles per year, with an assumed mix of 45% highway driving and 55% city driving, and using national average fuel prices as of the date of calculation. For the typical owner of a 911 GTS Cabriolet, this $3,050 annual expenditure is simply another line item in the budget for premium motoring. It’s a fraction of the vehicle’s purchase price and generally a minor consideration compared to insurance, maintenance, and depreciation. This buyer values the sensory experience, the howl of the naturally aspirated flat-six, the wind in their hair, the precise steering, far above minimizing their fuel bill. They understand that a vehicle engineered to this level of performance and luxury comes with associated running costs, and the fuel expense is entirely commensurate with ownership of such a high-caliber machine. For those genuinely concerned about every dollar spent on fuel, there are certainly more economical automotive choices, but none would deliver the unique thrill and prestige of a 911 GTS.

Real-world expectations

Real-world fuel economy for the 2025 911 Carrera GTS Cabriolet will closely mirror the EPA estimates for most drivers, assuming a relatively balanced driving style. However, the operative phrase here is “most drivers,” and 911 GTS owners are often not “most drivers.” Those who regularly exploit the vehicle’s immense performance capabilities, frequent hard acceleration, track days, or spirited canyon carving, should anticipate fuel economy figures closer to, or even below, the 17 MPG city rating. The advanced 3.6L six-cylinder engine, with its impressive power output, is incredibly sensitive to throttle input. Conversely, drivers who dedicate a significant portion of their mileage to long highway cruises with a light foot will likely see numbers at or even slightly above the 23 MPG highway rating. The 911 GTS is a car that encourages enthusiastic driving, and doing so will, by its nature, increase fuel consumption. The enjoyment derived from those moments, however, is precisely why this vehicle exists, and for its target demographic, the increased fuel burn is a worthwhile trade-off for the unparalleled driving theatre.

How it compares

The 2025 Porsche 911 Carrera GTS Cabriolet operates in a rarefied segment, and its fuel economy must be viewed in that context. Consider direct rivals like the Porsche 911 Turbo S Cabriolet, typically rated around 17 MPG combined, sacrificing a couple of MPG for even more outrageous power. An Audi R8 V10 Performance Spyder, with its naturally aspirated V10, generally lands around 15-16 MPG combined, clearly prioritizing auditory experience and raw power over efficiency. Even a more grand-touring focused option, such as a Mercedes-AMG SL 63 Roadster, usually offers around 19 MPG combined, despite its heavier curb weight, thanks to its twin-turbo V8. The BMW M4 Competition Convertible, while a different class of performance convertible, sits in a similar efficiency ballpark, often seeing around 20-21 MPG combined. When looking at 911 MPG across all years, the GTS holds its own, especially considering its strong performance. The 911 GTS’s 19 MPG combined rating places it squarely within its competitive set, demonstrating that its engineering manages a respectable balance between exhilarating performance and practical usability. It’s not an outlier; it’s a standard-bearer within its segment.

Tips to maximize efficiency

While the 911 GTS is not primarily an efficiency champion, mindful driving can still make a difference. Smooth throttle inputs are critical, avoid jerky acceleration and hard braking, as the advanced engine management system and transmission are designed to react to aggressive inputs with increased fuel delivery.

Engage the car’s “Normal” or “Comfort” driving modes for everyday use. These settings optimize the transmission shift points and engine response for smoother operation, which inherently reduces fuel consumption compared to the more aggressive “Sport” or “Sport Plus” modes.

Monitor tire pressure regularly. Incorrect tire pressure increases rolling resistance, forcing the engine to work harder. The 911’s precise handling is also dependent on correct pressures, making this a win-win for both safety and efficiency.

Use the automatic start/stop system. While some drivers find it intrusive, it demonstrably saves fuel in city driving by shutting off the engine at idle. On a high-performance engine like the GTS’, every little bit helps in congested traffic.

Plan your routes to avoid heavy traffic and unnecessary idling. The combination of a powerful 3.6L engine and the inherent inefficiencies of stop-and-go driving are the biggest drains on fuel economy for any high-performance vehicle.