24 MPG combined in the 2018 Porsche 911 Carrera 4S isn’t going to win any green awards, but that’s not the goal. This is a performance car designed to deliver a visceral driving experience, and buyers understand that compromise is sometimes necessary. Porsche engineering allows them to extract this level of efficiency from a turbocharged flat-six pushing over 400 horsepower, sent to all four wheels through a seven-speed dual-clutch transmission. Fuel economy is simply not the priority for buyers.

City and highway performance

The EPA estimates for the 2018 911 Carrera 4S are 21 MPG in the city and 28 MPG on the highway. These figures reflect the engine’s thirst when navigating stop-and-go traffic and its efficiency when cruising at consistent speeds. The 3.0-liter flat-six’s efficiency is bolstered by direct injection and intelligent thermal management, but spirited acceleration and the inherent drag of all-wheel drive take their toll in urban environments. The highway figure is more palatable, especially when using cruise control and resisting the urge to tap into the engine’s power. This balance means that while the 911 Carrera 4S is a thrilling everyday sports car, you will pay for that enjoyment at the pump.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Porsche 911 Carrera 4S at $2,400. This number is calculated based on driving 15,000 miles per year, using a national average fuel price. Understand this is an estimate, and driving habits and local fuel prices can significantly alter this figure. Someone who frequently drives aggressively in the city will easily exceed this amount, while someone who primarily drives on long highway trips and drives efficiently could potentially spend less. If you’re comparing this car against something with better fuel economy and are trying to justify the purchase, use that $2,400 annual fuel cost as a baseline.

Real-world expectations

While the EPA estimates provide a standardized benchmark, real-world fuel economy often varies. Owner reports suggest that achieving the EPA’s 28 MPG highway figure is realistic when driven conservatively. However, the combined figure of 24 MPG is more challenging to consistently reach. Many owners report averaging closer to 20-22 MPG in mixed driving conditions if they frequently tap into the engine’s power band. Realistically assess your driving style and typical usage when considering the 2018 911 Carrera 4S. Track days and repeated high-speed runs will clearly lower your MPG, while sticking to “Normal” mode and keeping the revs low during daily commutes will yield the best results.

How it compares

Compared to its rivals, the 2018 Porsche 911 Carrera 4S holds its own in terms of fuel economy. The Mercedes-AMG GT S, for example, with its twin-turbo V8, achieves an EPA-estimated 16 MPG city and 22 MPG highway. The added weight and displacement results in a significant fuel economy penalty. Even the lighter and smaller Audi R8 V10 Coupe manages only 13 MPG city and 20 MPG highway. The 911’s blend of power and efficiency is notable, especially considering its all-wheel-drive system. If fuel efficiency is a primary concern, the standard rear-wheel-drive 911 Carrera with the PDK transmission will offer slightly better numbers. You can also see 911 MPG across all years for other model year comparisons. The Carrera 4S is not about outright fuel sipping; it’s about balancing performance and day-to-day usability, and its fuel economy reflects that.

Tips to maximize efficiency

Use the “Normal” driving mode whenever possible, especially during daily commutes. This mode optimizes throttle response and gear selection for efficiency rather than outright performance, allowing the engine to operate at lower RPMs and consume less fuel. Resist the urge to constantly accelerate aggressively, as this diminishes fuel economy.

Ensure your tires are properly inflated to the recommended pressure, as this reduces rolling resistance and improves fuel efficiency. Check your tire pressure regularly, especially during temperature fluctuations. Improper tire inflation can also negatively impact handling and tire wear.

Avoid carrying unnecessary weight in the vehicle, as every extra pound contributes to increased fuel consumption. Remove any items from the trunk or rear seats that aren’t essential for your journey. This is applicable to any vehicle, but the 911’s primary purpose is driving enjoyment so there’s really no need to haul items around.

Anticipate traffic flow and maintain a consistent speed whenever possible. Avoid sudden braking and acceleration, as these actions waste fuel. Use cruise control on the highway to maintain a steady speed and optimize fuel efficiency during long drives.

Keep up with all scheduled maintenance, including regular oil changes and air filter replacements. A well-maintained engine operates more efficiently, leading to better fuel economy. Explore all Porsche fuel economy data for even more insights into the brand’s efficiency across its model range.