PRNewsFoto/Porsche Cars North America, Inc.
From Green Right Now reports
Nothing will say that hybrids have arrived in a big way more than the day you see “Hybrid” imprinted on a Porsche. That day will come next year when the Cayenne S Hybrid arrives with the power of a V8 and the fuel efficiency of a four-cylinder.
Porsche AG, the Stuttgart, Germany-based auto manufacturer, said today that the Cayenne S Hybrid is expected to emit some 20 percent less C02 than comparable combustion engine vehicles with similar power output. The company reports that Porsche engineers have been able to drive at speeds up to 86 mph without any use of the combustion engine.
The Cayenne S Hybrid will employ a parallel full hybrid design, with the electric motor between the combustion engine and the transmission. The company said the SUV has the power to reach 100 kilometers per hour in 6.8 seconds, but still meets Ultra Low Emission Vehicle II (ULEVII) emission standards.
Porsche says the Cayenne S Hybrid will roll freely – or “coast” — at highway speeds without the combustion engine on, greatly minimizing engine emissions and fossil fuel consumption. The hybrid technology employed by other automakers to day delivers benefits mainly in city traffic and is less effective at higher speeds.
Working in cooperation with Volkswagen, Porsche’s engineers favored the parallel full hybrid design because they said it would significantly improve acceleration. That approach also fits in the current Cayenne design with minimal alterations and without affecting interior space or luggage capacity, the company said.
The Cayenne S Hybrid will use a supercharged Audi 3.0-liter V6 engine with Direct Fuel Injection (DFI), 333 horsepower and 324 lb-ft of torque from 2,900 to 5,300 rpm. It is mated with a 52-horsepower, three-phase synchronous electric motor that produces up to 221 lb-ft of torque and also acts as an alternator. Those power units are joined to an eight-speed automatic transmission.
The Cayenne will have a 154-pound no-maintenance 38 kW nickel metal hydride (NiMH) battery that fits in the spare tire well, thus not affecting luggage capacity.
Porsche said all of this technology is the controlled by a Hybrid Manager, which requires some 20,000 data parameters to operate (conventional engine control units operate on less than one-third of the data). The Hybrid Manager’s main function is to coordinate the three power modes: power generated by the combustion engine and electric motor, power generated by the combustion engine only, and power generated by the electric motor only. A clutch is the key connection between the combustion engine and the electric motor, so the Hybrid Manager has to provide smooth, quick switching among the three hybrid modes without delay or a noticeable transition felt by the driver and passengers.
Porsche said the Cayenne S Hybrid can drive solely on electric power for up to 1.2 miles with the combustion engine off, and the Hybrid Manager will fire up the engine as soon as the driver presses the accelerator, increase engine speed appropriately and engage the clutch to transfer power to the transmission without the driver or passengers noticing what is happening. And, it does this within just 300 milliseconds.
The company said the Cayenne S Hybrid will consume less than nine liters of fuel per 100 kilometers in the New European Driving Cycle. EPA fuel economy figures are not yet available.
A similar hybrid system will find its way into the new Porsche Panamera four-door gran turismo sometime following Porsche’s fourth model line debut in late summer 2009.