Porsche unveils 918 Spyder hybrid sports car concept

New concept from Porsche is an efficient, low-emission, mid-engine super sports car that features hybrid and electric drive technology.

David Greenfield

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The 918 Spyder concept from Porsche combineshigh-tech racing features with electric mobility. Emission levels for the carare expected to be 70 grams of CO2 per kilometer on fuel consumption of onlythree liters/100 kilometers (equal to approximately 78 mpg U.S.). Performance-wise,this car is designed to accelerate from a standstill to 100 km/h in just under3.2 seconds, with a top speed of 320 km/h (198 mph), and a lap time on theNordschleife of Nurburgring of less than 7:30 minutes, faster than the PorscheCarrera GT.

The 918 Spyder is one of three Porsche models withhybrid drive making their world debut at the 2010 Geneva Motor Show. This trio-madeup of Porsche's new Cayenne S Hybrid SUV with parallel full-hybrid drive, the911 GT3 R Hybrid race car with electric drive on the front axle and a flywheelmass battery ( seerelated Control Engineering article ),and the two-seater high-performance 918 Spyder mid-engine sports car withplug-in hybrid technology-demonstrates the bandwidth of Porsche's new drivetechnology.

This open two-seater is powered by a V8 engine thatcreates more than 500 horsepower and a maximum engine speed of 9,200 rpm. Electricmotors on the front and rear axle provide an overall mechanical output of 218horsepower (160 kW). According to Porsche, the V8 combustion engine is the nextstep in the evolution of its 3.4-liter power unit already featured in the RSSpyder racing car and positioned mid-ship, in front of the rear axle, to providebalance and performance on the race track.

Power is transmitted to the wheels by a seven-speedPorsche-Doppelkupplungsgetriebe (PDK) transmission that feeds the power of theelectric drive system to the rear axle. The front-wheel electric drive powersthe wheels through a fixed transmission ratio.

The energy reservoir is a fluid-cooled lithium-ionbattery positioned behind the passenger cell. The advantage of a plug-in hybridis that the battery can be charged on the regular electrical network. Inaddition, the car's kinetic energy is converted into electrical energy fed intothe battery when applying the brakes, thus providing additional energy for fastand dynamic acceleration.

A button on the steering wheel allows the driver tochoose among four different running modes: The E-Drive mode is for running thecar under electric power alone, with a range of up to 25 km (16 miles). In theHybrid mode, the 918 Spyder uses both the electric motors and the combustionengine as a function of driving conditions and requirements, offering a rangefrom fuel-efficient to extra-powerful. The Sport Hybrid mode uses both drivesystems, but with the focus on performance. Most of the drive power goes to therear wheels, with torque vectoring serving to additionally improve the car'sdriving dynamics. In the Race Hybrid mode, the drive systems are focused on performance,running at the limit to their power and dynamic output. With the batterysufficiently charged, a push-to-pass button feeds in additional electricalpower (E-Boost), when overtaking or for even better performance.

Access other Control Engineering contentrelated to high-efficiency automobiles:

• Transportationindustry manufacturing groups call for cooperation on emissions and energyissues
• ABBrobots highlight Ford productivity, efficiency at Detroit Auto Show 2010
• Cana gasoline-diesel blend deliver cleaner, more efficient engines?

-Edited by DavidGreenfield , editorial director
Control Engineering Sustainable Engineering News Desk