21 MPG combined won’t win any hypermiling competitions, but for the 2017 Porsche 911 Turbo Cabriolet, it’s almost beside the point. This machine launches to 60 mph in under three seconds, a topless titan built for thrilling its occupants as much as transporting them. Fuel efficiency, in this rarified air, is simply a consequence of the performance on offer, a box barely ticked for a buyer driven by adrenaline, not frugality.

City and highway performance

The EPA estimates that the 911 Turbo Cabriolet achieves 19 MPG in the city and 24 MPG on the highway. Note that these figures are derived from a standardized testing cycle. Achieving them in the real world requires a degree of restraint utterly alien to the typical 911 Turbo driver.

In stop-and-go traffic, the prodigious power of the 3.8-liter flat-six is difficult to ignore, and the temptation to exploit even a fraction of its capability will inevitably impact fuel consumption. Out on the open road, a more disciplined driver might see figures approaching the EPA highway rating, particularly if using cruise control and resisting the urge to bury the throttle.

Annual fuel cost

The EPA estimates that the annual fuel cost for the 2017 Porsche 911 Turbo Cabriolet is $2,750. This figure is calculated based on driving 15,000 miles per year, using a blend of city and highway driving conditions, and factoring in the national average fuel price. Keep in mind that premium fuel is required for optimal performance in this car, which will increase the expense compared to vehicles that run on regular unleaded. Fluctuations in gas prices throughout the year can significantly impact your actual fuel costs.

Real-world expectations

Don’t be surprised if your real-world fuel economy falls short of the EPA estimates. The 911 Turbo Cabriolet begs to be driven hard, and its performance capabilities are intoxicating. Factors such as aggressive acceleration, frequent use of boost, and extended idling will all contribute to lower MPG. The optional sports exhaust system, while aurally pleasing, does little to promote fuel efficiency. Consider the EPA numbers a best-case scenario achieved under laboratory conditions; your mileage may vary, sometimes drastically. See 911 MPG across all years if you want to compare to other years.

How it compares

Compared to other high-performance convertibles, the 911 Turbo Cabriolet’s fuel economy is neither particularly impressive nor shockingly poor. The Mercedes-AMG SL63, with its 577-hp V8, achieves an EPA-estimated 16 MPG combined. The Audi R8 V10 Spyder, a direct competitor in terms of performance and price, manages a slightly better 17 MPG combined. The Jaguar F-Type R Convertible with its supercharged V8 also sits around 18 MPG combined.

A potential Porsche buyer is unlikely to cross-shop with mainstream competitors, but the comparison highlights the relative inefficiency of high-performance engines. The key takeaway for the 911 Turbo Cabriolet buyer? Fuel economy is a secondary concern. It’s about the experience. See all Porsche fuel economy data.

Tips to maximize efficiency

While outright fuel economy may not be a priority, there are still steps you can take to minimize fuel consumption in your 911 Turbo Cabriolet. Avoid aggressive acceleration and hard braking. The PDK transmission is remarkably efficient when left to its own devices, selecting appropriate gears for the driving conditions. Let it do its job and resist the urge to constantly override it with manual shifts unless you are on track.

Use “Normal” driving mode whenever possible. While “Sport” and “Sport Plus” modes sharpen throttle response and hold gears longer, they also drink fuel at a faster rate. The 911 Turbo has more than enough power in “Normal” mode for most situations. Save the more aggressive modes for spirited driving on back roads or at the track, not for daily commutes.

Ensure your tires are properly inflated. Under-inflated tires increase rolling resistance, which reduces fuel economy. Check your tire pressures regularly, especially before long drives. The recommended tire pressure can be found on a sticker inside the driver’s side doorjamb.

Minimize unnecessary weight. Carrying extra cargo in the trunk reduces fuel efficiency. Remove any items you don’t need, such as golf clubs or luggage, when not in use. Every pound counts, especially when you’re trying to squeeze every last mile out of a tank of premium fuel.

Have a light right foot. While the 911 Turbo Cabriolet begs to be pushed hard, resisting the urge to frequently unleash its full potential will reward you with better fuel economy. Smooth, gradual acceleration and anticipatory driving techniques contribute to noticeable gains without sacrificing too much driving enjoyment.