18 MPG combined won’t win any fuel economy awards, but for the 2021 Porsche Cayenne Turbo S e-Hybrid Coupe, a vehicle that blends supercar-rivaling performance with SUV practicality, it’s almost beside the point. This Cayenne exists for buyers who demand blistering 0-60 mph times, a luxurious and highly customizable interior, and the prestige of the Porsche crest. Fuel efficiency is simply not their primary concern.

City and highway performance

The EPA estimates the Cayenne Turbo S e-Hybrid Coupe achieves 17 MPG in the city and 20 MPG on the highway. This split reflects the vehicle’s character. While the electric motor provides some assistance in stop-and-go traffic, the twin-turbocharged 4.0L V8 is always ready to unleash its power. Highway cruising benefits from the hybrid system’s ability to coast and use electric power when appropriate, but even then, the Cayenne’s weight and aerodynamic profile limit its ultimate efficiency. Driving style has a significant impact. A lead foot will see those numbers plummet, while a more restrained approach can yield slightly better results. The automatic (S8) transmission shifts incredibly smoothly, either helping with, or hindering efficiency based on the mode selected.

Annual fuel cost

The EPA estimates an annual fuel cost of $3,200 for the 2021 Porsche Cayenne Turbo S e-Hybrid Coupe. This figure is based on driving 15,000 miles per year and using national average fuel prices. This is only an estimate, and your actual fuel costs will vary depending on your driving habits, local fuel prices, and the amount of time you spend driving in electric mode. Expect to pay more if you frequently exploit the vehicle’s performance potential.

Real-world expectations

While the EPA numbers provide a baseline, real-world fuel economy for the Cayenne Turbo S e-Hybrid Coupe is highly variable. Those primarily driving short distances and frequently charging the battery can significantly outperform the EPA estimates, potentially even doubling the MPG in some circumstances. Those who primarily drive long distances on the highway without charging will see numbers closer to, or even below, the EPA ratings. The temptation to use launch control and experience the full force of the powertrain will undoubtedly impact fuel consumption. The regenerative braking can add slightly to fuel economy in the city.

How it compares

The BMW X5 M Competition, a direct competitor, achieves a combined 15 MPG. The Mercedes-AMG GLE 63 S Coupe is rated at a similar 16 MPG combined. Even Tesla’s Model X Performance, while offering significantly better electric-only range, doesn’t necessarily translate to dramatically lower running costs for those who frequently take long trips or drive aggressively. It is also worthwhile to consider other models within the Porsche family; you can find CAYENNE MPG across all years. Buyers of the Turbo S e-Hybrid Coupe are cross-shopping these vehicles, despite the fuel economy differences, which highlights that performance, exclusivity, and brand image often outweigh efficiency concerns in this segment. For a broader view, see all Porsche fuel economy data.

Tips to maximize efficiency

Take full advantage of the hybrid system by frequently charging the battery. Short trips can be completed entirely on electric power, reducing fuel consumption to zero. Regular charging is important for maximizing the efficiency benefits.

Use the various driving modes to optimize fuel economy. The “Hybrid Auto” mode intelligently blends electric and gasoline power, while the “E-Hold” mode preserves the battery charge for later use in urban environments. The “E-Charge” mode can recharge the battery while driving, but this increases fuel consumption.

Avoid aggressive acceleration and braking. Smooth, deliberate driving conserves fuel in any vehicle, but it is particularly important in a high-performance hybrid like the Cayenne. Resist the urge to constantly tap into the Turbo S e-Hybrid’s power.

Ensure that your tires are properly inflated. Underinflated tires increase rolling resistance, which reduces fuel economy. Check your tire pressure regularly and inflate them to the recommended pressure listed on the doorjamb sticker.

Minimize aerodynamic drag. Remove roof racks and other accessories when not in use. Also, avoid driving at excessively high speeds, as wind resistance increases exponentially with speed.