Think of the electric motor in the facelifted 2015 Porsche Cayenne S E-Hybrid as the cream filling in an Oreo cookie. Under the hood of this plug-in hybrid crossover is a 333-horsepower, supercharged 3.0-liter V6 with a 95-hp synchronous electric motor sandwiched between it and an eight-speed Tiptronic automatic transmission. The clutched powertrain allows pure combustion, pure electric or a combination of both to drive all four wheels through Porsche’s permanent all-wheel-drive system.
Differentiating itself from the Panamera S E-Hybrid sedan, which shares the same basic powertrain and stores energy in a 9.4-kWh battery, the Cayenne crossover is fit with a more robust 10.8-kWh lithium-ion battery that delivers an estimated pure-electric driving range of up to 22 miles at speeds of up to 78 miles per hour.
To be one of the very first US media members to sample Porsche’s latest fuel-efficient crossover, the automaker flew us to Frankfurt, Germany, to test the five-passenger Cayenne S E-Hybrid on its home turf.
- In default mode, the hybrid system requires no operator input. Assuming the battery pack has sufficient charge, this Porsche will start and drive on electric power until it has exhausted nearly all of its battery pack’s stored energy (state of charge is visible on the infotainment display), at which point, the combustion engine will start and provide propulsion. However, in the interest of fuel economy, it will not recharge the battery above a minimal level.
- Crucially, Porsche has fitted two console-mounted buttons that are unique to the Cayenne E-Hybrid. That’s because, as engineers point out, there will be times when drivers want to preserve EV mode for city driving (as in London’s city center, to avoid congestion charges) and/or recharge their batteries on the open road. The top button, or ‘E-Power’, forces the powertrain into pure EV mode (assuming there is energy in the battery, of course) for emissions-free driving. The bottom button, or ‘E-Charge’, starts the combustion engine and engages the electric motor in a generator role to restore approximately 80 percent of the battery’s charge in about 30 minutes. The downside to the latter is a 20-percent reduction in fuel economy as the engine is being used for propulsion and charging.
- The Cayenne S E-Hybrid may be on an efficiency mission, but there are no compromises in terms of performance. Full throttle engages both the engine and e-motor, with their combined output launching the nearly 5,200-pound crossover to 60 mph in just 5.4 seconds and on to a top speed of 151 mph (pure EV mode is several ticks slower in acceleration benchmarks). It’s surprisingly quick, with the competent eight-speed automatic working with the driveline’s rear-biased all-wheel drive to expertly lay the power down.
- We found ourselves constantly toggling between E-Power and E-Charge, staring intently at the instrument panel’s Energy Flow gauge as we drove through both city and open countryside seeking different levels of performance and efficiency. Electric mode is expectedly hushed, with the motor’s whine barely audible in the cabin (more pronounced is the tire noise from the performance-oriented rubber). The combustion engine introduces vibration and a V6 rumble from the other side of the firewall when it switches on, making it obvious as to which mode the powertrain is operating in.
- The battery pack, located in the rear of the vehicle beneath the cargo floor, can be recharged with a Porsche Universal Charger. Charge time using a standard 110-volt/10-amp household outlet is approximately 11 hours, 240-volts/16 amps is approximately 2.7 hours and 240-volts/30 amps is approximately 1.3 hours. EPA fuel economy estimates have not yet been released.
- Dynamically, the E-Hybrid’s steering, braking and handling are nearly identical to other Cayennes, despite the additional heft from the sophisticated drive system (the Hybrid weighs a whopping 613 pounds more than the Cayenne S). The crossover may be on a fuel-efficient mission, but its driving dynamics are all Porsche – the driver will enjoy the experience. We confidently tossed the crossover into corners for grins and drove at triple-digits speeds simply because we legally could (of course, neither practice is good for economy). The only oddity, from the operator’s perspective, is the drive-by-wire accelerator pedal that alters its resistance (and kick-down point) based on the hybrid mode – it takes some getting used to.
- Porsche offers versions of its midsize crossover to suit every upper-crust need, from the entry-level naturally aspirated V6-powered Cayenne to the muscular twin-turbocharged V8-powered Cayenne Turbo. The Cayenne S E-Hybrid sits mid-pack in terms of pricing and standard equipment, targeting efficiency-minded buyers who spend most of their time driving time in urban environments, where hybrids shine. Strictly in terms of range and fuel economy, however, those who commute large distances are better served by the Cayenne Diesel.
We really like the updated 2015 Porsche Cayenne S E-Hybrid, but not simply because of its newly extended electric range and improved efficiency. More important, we are impressed by how well engineers have been able to seamlessly integrate such a complex hybrid system within the midsize crossover, yet take very little away from its enthusiast-tuned driving dynamics.