2020 Porsche 718 Cayman GT4: Fuel Economy Deep Dive

19 MPG combined won’t win any hypermiling contests, but for the Porsche 718 Cayman GT4, it’s a figure that’s largely irrelevant to its core mission and intended audience. This car isn’t about sipping fuel; it’s about delivering a visceral, unfiltered driving experience centered around a naturally aspirated 4.0-liter flat-six engine and a six-speed manual transmission. The kind of person who buys a GT4 isn’t cross-shopping it with a Prius. They are buying it for a specific, focused purpose: pure driving enjoyment, likely including track days and spirited weekend drives. Fuel costs are simply a cost of admission.

City and highway performance

The EPA estimates the 2020 Porsche 718 Cayman GT4 at 16 MPG in the city and 23 MPG on the highway. These figures accurately reflect the car’s nature. The city MPG suffers because the GT4 begs to be driven with enthusiasm, which directly translates to higher fuel consumption. The aggressive gearing and responsive throttle encourage frequent shifts and playful acceleration. On the open road, the 23 MPG highway figure is realistically achievable at legal speeds, showcasing that the GT4 can be reasonably efficient when driven with restraint, though restraint is rarely a GT4 driver’s first instinct.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2020 Porsche 718 Cayman GT4 at $3,050. This figure is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway, using national average fuel prices. Owners should understand that this is just an estimate. Someone who primarily tracks their GT4 or uses it for short, aggressive drives will likely far exceed this cost. The $3,050 estimate provides a baseline, but ultimately fuel expenses will heavily depend on individual driving habits and local fuel prices.

Real-world expectations

Expect some variation from the EPA estimates in real-world driving conditions, even if you try to drive efficiently. Factors like traffic congestion, aggressive driving, and even tire pressures will play a role. The 718 Cayman GT4 also requires premium fuel, which will affect fill-up costs. Those who frequently engage “Sport” mode or spend time on the track will undoubtedly see their fuel economy dip below both the city and combined EPA ratings fairly regularly. The reward for that spirited driving, however, is an unmatched connection to the road and a truly engaging driving experience.

How it compares

The 718 Cayman GT4 exists within a niche of performance-focused, naturally aspirated sports cars. Comparing it to other vehicles provides perspective for prospective buyers. The BMW M2 Competition, while turbocharged, offers similar performance and gets a slightly better 20 MPG combined. The Chevrolet Corvette Stingray, with its significantly more powerful V8, achieves a surprisingly similar 19 MPG combined in manual guise. However, the GT4 buyer is often prioritizing a specific driving feel and engagement that those other cars, while excellent in their own right, simply don’t replicate. For those interested in lower numbers along the board, you can view all Porsche fuel economy data here or 718 MPG across all years.

Tips to maximize efficiency

While fuel economy might not be your top priority as a GT4 owner, there are still ways to improve mileage without sacrificing too much enjoyment. One simple method is to shift earlier in the rev range during normal driving. The GT4’s engine is tractable, and you don’t need to reach the redline for every gear change during daily commutes.

Tire pressure plays an important role in fuel efficiency. Ensure your tires are inflated to the recommended pressure, which can be found on the doorjamb. Underinflated tires increase rolling resistance, leading to decreased fuel economy. Regularly checking and maintaining proper tire pressure is a simple yet effective way to manage fuel consumption.

Avoid aggressive acceleration and braking whenever possible. Smooth inputs are key to fuel-efficient driving. The less you abruptly apply the throttle or slam on the brakes, and the less gas you’ll consume. This also translates to smoother, more comfortable driving experience, even in a performance-oriented car like the GT4.

Consider using a fuel additive designed to clean your fuel system. A clean fuel system ensures optimal fuel delivery and combustion, which can improve fuel economy. Consult your owner’s manual or a Porsche technician to determine the best fuel additive for your GT4.