22 MPG combined might sound modest on paper, but in the context of a thoroughly engaging, mid-engined roadster like the 2025 Porsche 718 Boxster S, engineering efficiency is evident. This isn’t a vehicle bought for its frugality; it’s acquired for the visceral connection between driver, road, and a perfectly balanced chassis. Yet, even within the realm of pure sports cars, Porsche has managed to deliver a power plant that can surprise with its relative restraint at the pump, particularly given the exhilarating performance on tap from its 2.5L turbocharged flat-four.

City and Highway Performance

Looking at the 718 Boxster S’s EPA figures, we find 19 MPG in the city and 25 MPG on the highway. The city figure, 19 MPG, reflects the inevitable stop-and-go demands placed on a high-performance engine, amplified by the inherently less efficient nature of urban driving. This is where the turbocharged 2.5L engine, despite its advanced design and the PDK’s quick shifts, still faces thermodynamic challenges unique to frequent acceleration and deceleration. Owners of the Boxster S typically prioritize the immediacy of throttle response and the symphony of the engine note over maximizing urban mileage, embracing these numbers as simply part of the sports car experience.

The highway number, 25 MPG, is where the 2.5L four-cylinder truly shines in terms of relative efficiency. Cruising at highway speeds, the engine can settle into a less demanding operating range. The smooth shifts of the automatic (AM-S7) transmission keep revolutions low, while the aerodynamic profile of the Boxster, designed for stability at speed, contributes to reduced drag. For those long weekend drives to mountain roads or coastal highways, where the Boxster S truly comes alive, owners will appreciate the ability to cover significant distances without constant fuel stops, allowing more time to enjoy the open air and the incredible handling dynamics. It’s a pragmatic balance for a vehicle so intensely focused on driving pleasure.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,650 for the 2025 Porsche 718 Boxster S. This figure is calculated based on an assumption of 15,000 miles driven per year, split between city and highway driving, using national average fuel prices for premium gasoline. For prospective Boxster S owners, this $2,650 per year represents a measurable running cost, but it’s one almost universally accepted as part of the total ownership experience. Buyers of this car are acutely aware that a Porsche, particularly a performance model, entails premium fuel. The cost of fuel is often a minor consideration when weighed against the joy of driving a car with such impeccable steering feel, a responsive chassis, and an engine that delivers intoxicating power. It becomes another line item in the budget of enthusiast ownership, far overshadowed by the depreciation, insurance, and maintenance costs associated with a high-end sports car.

Real-world expectations

In real-world driving, the 2025 Porsche 718 Boxster S delivers fuel economy figures that can vary significantly from the EPA estimates, largely dependent on the driver’s enthusiasm. For owners who frequently explore the upper reaches of the tachometer, engage Sport or Sport Plus modes, and regularly exploit the car’s phenomenal acceleration on winding roads, mileage will understandably dip below the 22 MPG combined figure. This is precisely how many Boxster S owners choose to drive, extracting every ounce of performance from the 2.5L engine. The addictive boost and flat-four rumble encourage spirited driving, and part of the ownership agreement is acknowledging that such exhilaration comes with a corresponding thirst for premium fuel.

Conversely, for those drivers who temper their exuberance, perhaps using the Boxster S for longer highway commutes or more relaxed touring, the 2.5L engine can surprise with its efficiency. The PDK transmission’s ability to select the optimal gear, often coasting when possible, and the relatively light weight of the Boxster S work in concert to achieve or even slightly exceed the EPA highway numbers, particularly in disciplined driving scenarios. It’s a fact of Porsche’s engineering that such a capable sports car can also be a reasonably efficient cruiser when the mood dictates, though most buyers purchase this vehicle precisely for the moments when efficiency is the furthest thing from their minds. For more information on Porsche’s overall fleet efficiency, check out all Porsche fuel economy data.

How it compares

When placed next to its direct competitors, the 2025 Porsche 718 Boxster S (22 MPG combined) holds its own remarkably well in terms of fuel economy, often outperforming or matching rivals that don’t deliver the same level of driver engagement or brand cachet. Consider the Chevrolet Corvette Stingray C8, with its naturally aspirated V8. The base Corvette achieves 19 MPG combined (16 city / 24 highway), demonstrating that the Boxster S’s turbocharged four-cylinder offers a distinct efficiency advantage for similar performance thrills, especially in city driving. The Audi TT RS, while an entirely different vehicle class (a coupe, not a roadster), offers a 2.5L five-cylinder and nets 22 MPG combined (20 city / 29 highway), showcasing a similar overall efficiency profile, though its front-biased all-wheel-drive dynamics are vastly different from the Boxster’s mid-engined, rear-wheel-drive setup. The BMW Z4 M40i, with its excellent 3.0L inline-six, achieves 26 MPG combined (23 city / 30 highway), making it notably more efficient than the Boxster S while offering a different, albeit still engaging, driving character. However, none capture the unique mid-engine balance and surgical precision that define the Boxster S.

These comparisons illustrate that while the Boxster S is not the absolute fuel economy king in its segment, it’s far from a fuel guzzler. The slightly lower MPG compared to some rivals is easily justified by its unparalleled chassis dynamics, the allure of the Porsche badge, and the specific connection it establishes with the driver. Buyers seeking a 718 understand that they are paying for a finely honed driving instrument, and its fuel economy, while reasonable, is rarely the decisive factor. For a specific look at how this model compares across generations, explore 718 MPG across all years.

Tips to maximize efficiency

While maximizing fuel efficiency isn’t the primary goal for most 718 Boxster S owners, understanding how to drive more efficiently can extend range and lower running costs when desired. Employing smooth, progressive throttle inputs is key, abrupt acceleration and deceleration waste fuel in any vehicle, especially one with a turbocharger that builds boost enthusiastically. Use the torque curve of the 2.5L engine by maintaining lower RPMs when cruising, allowing the PDK transmission to select higher gears early, reducing the energy required to maintain speed.

Actively engaging the auto start/stop system in urban environments can noticeably reduce fuel consumption, although some drivers prefer to disable it for a more smooth experience. This system temporarily shuts off the engine when the vehicle is stationary, such as at traffic lights, and restarts it almost instantly when the brake pedal is released, preventing idle fuel waste.

Regular maintenance, including proper tire inflation and timely oil changes, impacts efficiency. Underinflated tires increase rolling resistance, forcing the engine to work harder. Keeping the air filter clean ensures the engine breathes optimally, contributing to more efficient combustion.

Finally, minimizing unnecessary weight in the frunk and trunk, while perhaps a marginal gain for a car with the Boxster S’s power-to-weight ratio, cumulatively reduces the effort required for acceleration. Every pound removed translates to less energy expended, a philosophy intrinsically linked to sports car design.