19 MPG combined isn’t going to win any awards, but it’s almost beside the point for the 2024 Porsche 911 Carrera 4 GTS Cabriolet. This isn’t a car purchased for its frugality; it’s acquired for its soundtrack, its precision, and its ability to transform any road into an occasion. The buyer prioritizing this car knows its mission, and the fuel bill is a known consequence of that commitment.

City and highway performance

The EPA estimates break down to 17 MPG in the city and 22 MPG on the highway for this all-wheel-drive convertible. The source of the thrill is the 3.0-liter twin-turbocharged flat-six engine producing 473 horsepower. It is mated to an 8-speed dual-clutch automatic transmission (AM-S8), and its response is immediate and ferocious. Start-stop technology is present to mitigate consumption in stop-and-go traffic, but it’s unlikely to make a significant impact on the overall city MPG for drivers who are indulging in the car’s performance capabilities. A more relaxed driving style on the highway will yield closer to the 22 MPG figure, but even then, the temptation to exploit the GTS’s prodigious power will likely keep it a bit lower.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 Porsche 911 Carrera 4 GTS Cabriolet at $3,050. This figure is calculated based on driving 15,000 miles per year and using national average fuel prices. Naturally, your individual fuel costs will vary depending on your driving habits, the type of fuel you use (premium is required), and local fuel prices. But $3,050 offers a benchmark for prospective owners and can be compared to other options. It also provides a clear window into where the fuel dollars go: performance and driving enjoyment.

Real-world expectations

While the EPA provides a useful baseline, real-world fuel economy often diverges, sometimes significantly. Aggressive acceleration, frequent shorter trips where the engine doesn’t reach optimal operating temperature, and sustained high-speed cruising will all negatively impact fuel consumption. Disciplined driving with a focus on smooth acceleration and anticipation can nudge the numbers closer to, or even slightly above, the EPA estimates. As with any performance vehicle, the driver’s habits are a major factor.

How it compares

The 911 GTS Cabriolet occupies a unique space, blending high performance with open-top thrills. A BMW M4 Competition Convertible, with its 503-hp inline-six and all-wheel drive, achieves roughly 18 MPG combined. While that is nearly comparable to the 911, buyers are likely to cross-shop it with the 911 based on price as well as overall driving experience. The Mercedes-AMG SL63, a more luxurious albeit less focused alternative, manages around 16 MPG combined with its V8 engine. Even within the Porsche family, exploring 911 MPG across all years reveals a performance fuel economy tradeoff. Other models like the 911 Carrera T with a manual transmission can achieve slightly better fuel economy with a slightly less powerful engine offering a more driver-centric experience, or the 911 Turbo S with even more power at a similar fuel economy level. These comparisons highlight that while the 911 GTS Cabriolet isn’t a fuel sipper, it offers a balance against similarly capable alternatives.

Tips to maximize efficiency

The twin-turbo flat-six loves to rev, but keeping the engine in its lower RPM range during everyday driving will noticeably improve fuel consumption. Resist the urge to constantly explore the upper reaches of the tachometer; save that for special occasions.

The 8-speed dual-clutch transmission is remarkably responsive in Sport and Sport Plus modes, but it will also hold gears longer, burning more fuel. Use the Normal drive mode for regular commuting; it prioritizes higher gears and lower RPMs.

Ensure that your tires are properly inflated. The recommended tire pressure is listed on a sticker inside the driver’s side door jamb. Properly inflated tires reduce rolling resistance, improving fuel economy and maximizing tire life.

Avoid unnecessary weight in the vehicle. The lighter the car, the less energy it takes to accelerate and maintain speed. Remove any items from the trunk or rear seats that you don’t need.

Plan your trips to avoid stop-and-go traffic whenever possible. Constant acceleration and braking consume significantly more fuel than maintaining a steady speed. Taking a slightly longer route with less traffic can often save fuel and time.