21 MPG combined won’t win any hypermiling contests, but for a 3.8-liter, naturally-aspirated flat-six powering all four wheels in a drop-top Porsche 911, it shows the engineering priorities. This isn’t a car bought by people prioritizing lower fuel costs. It’s a machine purchased by enthusiasts who want raw, unfiltered power combined with open-air thrills; relative efficiency is simply a bonus. They’ll gladly accept this fuel consumption figure in exchange for the driving experience this specific 911 delivers.

City and highway performance

The EPA rates the 2016 Porsche 911 Carrera 4S Cabriolet at 19 MPG in the city and 26 MPG on the highway. While the highway number offers a glimmer of hope on longer journeys, the city figure accurately reflects the reality of stop-and-go driving. Turbocharged engines often excel in city environments due to their low-end torque, but the 3.8L flat-six needs to be revved to its sweet spot, frequently putting the driver in a position to use more fuel to access its capabilities.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2016 Porsche 911 Carrera 4S Cabriolet at $2,750. This figure is based on driving 15,000 miles per year and using national average fuel prices. Drivers who live in areas with higher fuel costs, or those who frequently indulge in spirited driving, can realistically expect to spend more than this amount at the pump. The calculation assumes an even mix of city and highway miles, a condition many 911 owners may not experience. It’s crucial to understand this is just an estimate; individual driving habits heavily influence the actual fuel costs.

Real-world expectations

Do not expect to consistently achieve the EPA’s numbers in real-world driving. The temptation to hear the exhaust note roar as you accelerate hard out of corners or downshift for maximum passing power is simply too strong for most 911 owners to resist. Driving with the top down also adds to the aerodynamic drag, which negatively affects MPG. Expect to see numbers slightly below the EPA estimates, especially if your commute involves heavy traffic or if you routinely enjoy the car’s performance potential. The payoff, of course, is an unmatched driving experience.

How it compares

Compared to its peers, the 2016 911 Carrera 4S Cabriolet’s fuel economy places it in a unique position. The Mercedes-AMG GT Roadster, for instance, achieved a lower 18 MPG combined. An Audi R8 Spyder V10 fares similarly, often struggling to break 17 MPG combined. Even smaller sports cars with similar performance aspirations like a Chevrolet Corvette Stingray Convertible with the automatic transmission can realistically achieve around 20 MPG combined, making the 911’s 21 MPG seem more respectable when viewed in context. Drivers considering the Porsche often aren’t cross-shopping based purely on lower fuel costs, but the 911’s positioning relative to other high-performance convertibles is worth acknowledging. Consider looking at 911 MPG across all years to consider other model years.

Tips to maximize efficiency

Using the Porsche’s multi-mode driving settings can boost mileage. The “Normal” or “Eco” modes will alter throttle response and shift points to prioritize fuel efficiency over outright performance. Use these modes during mundane commutes or long highway stretches to conserve fuel. Sport and Sport Plus modes offer significantly better throttle response but at the expense of using significantly more fuel.

Maintaining proper tire inflation is critical for optimal fuel economy and performance. Check your tires regularly and adhere to the pressure specifications listed on the door jamb sticker. Underinflated tires increase rolling resistance, leading to decreased fuel efficiency, worse handling, and potentially premature wear.

While tempting, avoid unnecessary idling. Modern engines are designed to be efficient even when restarted. If you anticipate being stationary for more than a minute, turn off the engine to save fuel. This is particularly relevant in congested city environments.

Gentle acceleration and braking are key to maximizing fuel efficiency in virtually any vehicle. The 911 Carrera 4S Cabriolet possesses a prodigious amount of power, but smooth, progressive throttle inputs will help you conserve fuel and avoid abrupt downshifts. Similarly, anticipate traffic flow and avoid hard braking, which wastes energy.

Consider browsing all Porsche fuel economy data.