And because of Porsche's technology focus, the brand's buyers are more likely to consider hybrid models, argues Dr. Michael Leiters, the project leader for the Cayenne.
The all-new full parallel hybrid system in the Cayenne S Hybrid—developed together with that of the 2011 Volkswagen Touareg Hybrid—employs a 333-horsepower, 3.0-liter supercharged V-6 (actually, the exact same engine as offered in the Audi S4) and a 47-hp (34 kW) electric motor system to, Porsche says, offer the performance of a V-8 and the economy of a V-6. With a dry decoupling clutch—very carefully managed with electronics—the system can select one power source or the other, or both. Performance is no penalty box; the Hybrid is far faster than the Cayenne V6, at 6.1 seconds to 60 mph and a top speed of 150 mph.
No need to feather-foot to reap the benefits
This system is described as quite different than other hybrid systems in that it was designed to provide mileage gains not only when driving slowly and gently—or when accommodating certain powertrain oddities (such as the Prius-friendly pulse-and-glide). Porsche programmed the hybrid system to always be on the ready with both power sources if needed so that strong torque is available right at tip-in, not a moment later, with a throttle response that's more characteristic of a sports car than a green vehicle. "You can drive it like a Porsche," declared Leiters.
Rather than the normal and eco modes that some more green-focused hybrids have, the Cayenne S Hybrid has normal and Sport modes, affecting the engagement of the power sources and how aggressively they join in. While full electric boost might come at only full throttle in normal mode, it will kick in at two-thirds throttle in Sport mode, for instance.
Also unique to this sporting hybrid is the idea of 'sailing'—a German-based term for coasting or freewheeling. With the clutch pack disengaging both power sources completely, the Cayenne Hybrid can 'sail' at up to 97 mph, allowing the gasoline engine to turn off and to take advantage of increased fuel-efficiency even at those higher speeds.
Sailing, sailing on the autobahnOn a slightly downhill Interstate grade we tested this, gently lifting off the accelerator, at 85 mph, and the Cayenne very gradually lost speed, sailing along, until we either rolled back into the gas (when the rev counter almost instantly sprang up) or when we tapped the brake pedal, which activated the regenerative braking.
Another interesting behavior in the 2011 Cayenne S Hybrid is that, in electric mode, the transmission will shift up to second gear if you take off gently enough. Porsche says that the Cayenne can cover short distances in EV mode at speeds of up to 40 mph, though on a hot day with the air conditioning on, we typically saw the gasoline engine kick in at about 10 or 15 mph under gentle acceleration.