2010 Porsche Cayenne S Hybrid Details

The 2010 Porsche Cayenne S Hybrid will be a so-called "full hybrid," meaning it can run on either or both power sources, as the situation requires.

The 2010 Porsche Cayenne S Hybrid should be based on the updated 2008 model with the obvious exception of the powertrain, which is another joint ventu­re with Volkswagen and Audi. We see that first in a gasoline/electric Audi Q7 that's due in calendar 2008 as an '09 model. (VW hasn't yet announced timing for its hybrid Touareg.) The drive system is a so-called "full hybrid," meaning the vehicle can run on either or both power sources as driving needs require. The gas engine is a direct-injected Audi 3.0-liter V6, while the electric drive employs a newly developed 240-cell nickel-metal-hydride battery pack that weighs 152 pounds, produces a peak 288 volts, and is small enough to fit in the spare-tire well (which could mean standard run-flat tires). An electric motor functioning as a starter/generator mounts between the engine and a new 8-speed automatic transmission without the usual torque converter. An electronic control module--what Porsche calls a "Hybrid Manager"--coordinates the power sources. Gas or electric, the tra­nsmission/clutch assembly drives all four wheels, as in other Cayennes.

­Porsche and its partners estimate their hybrids will have around 25-percent better fuel economy than conventional V6 counterparts--an overall 24 miles per gallon to start and perhaps 26 later on.

The Cayenne S Hybrid may be Porsche's first gas/electric vehicle, but it won't be the last. Porsche says a similar system will be available for its first sedan, the 2010 Panamera, which bows with conventional V8 power in 2009. The hybrid version follows about a year later as a 2011 model.

A Notable Feature of the 2010 Porsche Cayenne S Hybrid

Porsche terms its hybrid setup an "inline configuration" because the electric motor sits between the gas engine and transmission/clutch assembly, rather than off to the side. The company says it chose this arrangement as being more "compatible" with the Cayenne platform--and also more fuel-efficient in testing, according to a press release. Like some other gas/electric vehicles, the 2010 Porsche Cayenne S Hybrid maximizes mpg by using electric motors instead of power-sapping mechanical drives to run the power steering and air-conditioning compressor. Porsche, however, goes two steps further with an electrically operated brake booster and transmission oil pump. All told, the hybrid system adds a modest 310 pounds or so to the normal V6 Cayenne's 4,762-pound curb weight. That includes the 88-pound "Hybrid Manager," claimed to be the most powerful computer ever used in a vehicle.

With all this and specially developed software, the 2010 Porsche Cayenne S Hybrid won't drive like a Toyota Prius. We understand it can run solely on electric power up to 31 mph, which is high for a hybrid. Remarkably, Porsche says company engineers have run on volts alone at up to 86 mph on a steady throttle, which sounds like a real fuel-saver on the highway. Like most every hybrid, the Cayenne system incorporates a regenerative-braking function that turns the motor into a generator for juicing up the battery when coasting or braking.