The 2024 Porsche 718 Cayman S, with its strong 2.5L turbocharged four-cylinder, gets 22 MPG combined, which isn’t going to win any fuel efficiency awards, but it represents an acceptable compromise. Buyers in this segment aren’t prioritizing hypermiling; they’re seeking a visceral driving experience, razor-sharp handling, and the prestige of the Porsche crest. The Cayman S delivers all of that, and a mid-20s MPG figure is the price of admission.

City and highway performance

The EPA estimates the 2024 Porsche 718 Cayman S at 19 MPG in the city and 25 MPG on the highway. The city figure reflects the reality of stop-and-go traffic, frequent acceleration from a standstill, and the inherent inefficiencies of a performance-oriented engine. The highway number, while better, is somewhat restrained by the Cayman S’s relatively short gearing, designed for rapid acceleration rather than ultimate cruising efficiency, alongside the aerodynamic realities of its sporty profile.

While 25 MPG on the highway isn’t dismal, it’s important to remember that enjoying the car’s performance, even on the open road, will likely pull that number down. The quick-shifting automatic (AM-S7) transmission does its best to optimize fuel usage, but ultimately, driver behavior significantly impacts the car’s real-world numbers.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 Porsche 718 Cayman S at $2,650. This figure is based on driving 15,000 miles per year, with 45% of those miles driven in the city and 55% on the highway, using national average fuel prices. However, this number is a guideline.

Drivers who spend more time in heavy traffic, have a heavier foot, or live in areas with higher fuel costs will likely exceed this estimate. Those who primarily use the Cayman S for long highway trips, and drive conservatively, might see a slightly lower annual fuel expenditure. It’s also a good idea to reference all Porsche fuel economy data, as there are more economical Porsche options.

Real-world expectations

While the EPA figures provide a baseline, real-world fuel economy for the 2024 Porsche 718 Cayman S will vary based on driving style and conditions. Drivers who frequently engage the sport exhaust, use launch control, or spend considerable time on twisty backroads should realistically expect to see average fuel economy figures closer to the low end of the EPA range, or even slightly below.

Those who primarily use the Cayman S for commuting or relaxed highway cruising, and are mindful of their throttle inputs, may be able to achieve numbers closer to the EPA’s 25 MPG highway estimate. It’s crucial to factor in your own driving habits when considering the true cost of ownership.

How it compares

The 2024 Porsche 718 Cayman S doesn’t exist in a vacuum, so how does its fuel economy stack up against the competition? A BMW M240i xDrive Coupe, with its turbocharged inline-six and all-wheel drive, achieves a combined EPA rating of 26 MPG. That’s noticeably better than the Cayman S, but it lacks the mid-engine balance and outright sharpness of the Porsche. The Alpine A110, a direct competitor from across the Atlantic, manages around 30 MPG combined, but it sacrifices horsepower and power delivery in the name of efficiency.

Compared to the bigger Porsche 911 Carrera, which achieves an EPA-estimated 21 MPG combined, the Cayman S actually provides a small economy advantage. These comparisons matter because while Cayman S buyers aren’t solely focused on fuel economy, they still want to understand where the car stands relative to other performance vehicles. Comparing 718 MPG across all years may also be informative when searching for a vehicle.

Tips to maximize efficiency

Use the Normal driving mode as often as possible. The Sport and Sport Plus modes enhance throttle response and hold gears longer, which are great for performance driving but significantly increase fuel consumption. In everyday driving, the Normal mode provides adequate performance while prioritizing efficiency. Become familiar with the car’s “coasting” or “sailing” function.

When conditions allow, lifting off the accelerator pedal will decouple the engine from the transmission, allowing the car to coast freely without engine braking. This reduces fuel consumption and can be especially effective on downhill stretches or when approaching traffic lights.

Maintain proper tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and reducing fuel economy. Check your tire pressures regularly and inflate them to the manufacturer’s recommended levels, found on the doorjamb placard.

Avoid unnecessary idling. Letting the engine idle for extended periods wastes fuel. If you’re stopped for more than a minute or two, it’s generally more fuel-efficient to turn off the engine and restart it when you’re ready to go. Consider the weight of the items you keep in your car. Extra weight increases the amount of fuel required to get up to speed, so remove anything unnecessary from the trunk and passenger compartment.