|Phantom diagram of the 918 Spyder with plug-in hybrid technology. Click to enlarge.|
In addition to introducing the flywheel KERS equipped 911 GT3 R hybrid for production-based GT racing (earlier post) and the Cayenne S Hybrid (earlier post) at the Geneva Motor Show, Porsche unveiled the plug-in hybrid Porsche 918 Spyder concept car.
The mid-engined two-seater is powered by a high-speed V8 developing more than 500 bhp (373 kW) and running at maximum speed engine of 9,200 rpm as well as electric motors on the front and rear axle with overall mechanical output of 218 bhp (160 kW). Porsche says that concept combines the performance of a super-sports car with the CO2 emissions of a small compact, with fuel consumption of 3.0 L/100 kilometers (78.4 mpg US) and 70 grams CO2 per kilometer in its most economical operating mode.
|Michael Macht, the President and Chief Executive Officer of Dr. Ing. h.c. F. Porsche AG and Walter Röhrl presenting the Porsche 918 Spyder concept car before the opening of the Geneva show. Click to enlarge.|
Acceleration from 0 to 10 km/h takes less than 3.2 seconds, and the 918 concept has a top speed of 320 km/h (198 mph), and a lap time on the Nordschleife of Nürburgring in less than 7:30 minutes—faster than the Porsche Carrera GT.
The V8 combustion engine is a further development of the 3.4-liter power unit already featured in the RS Spyder racing car. Power is transmitted to the wheels by a seven-speed Porsche-Doppelkupplungsgetriebe also feeding the power of the electric drive system to the rear axle. The front-wheel electric drive powers the wheels through a firm transmission ratio. A grid-chargeable liquid-cooled lithium-ion battery pack is positioned behind the passenger cell.
A button on the steering wheel allows the driver to choose among four different running modes:
The E-Drive mode is for running the car under electric power alone, with a range of up to 25 km (16 miles).
In the Hybrid mode the 918 Spyder uses both the electric motors and the combustion engine as a function of driving conditions and requirements, offering a range from particularly fuel-efficient all the way to extra powerful.
The Sport Hybrid mode uses both drive systems, but with the focus on performance. Most of the drive power goes to the rear wheels, with Torque Vectoring serving to additionally improve the car’s driving dynamics.
In the Race Hybrid mode the drive systems are focused on pure performance with the highest standard of driving dynamics on the track, running at the limit to their power and dynamic output. With the battery sufficiently charged, a push-to-pass button feeds in additional electrical power (E-Boost), for example when overtaking or for even better performance.
The modular structure with its monocoque bodyshell made of carbon-fibre-reinforced plastic (CFP) and the appropriate use of magnesium and aluminium reduces weight to less than 1,490 kg (3,285 lbs).