An Ultra-Fast PHEV-16 Super Sports Car in Geneva.
Wayne Gerdes -
CleanMPG - Mar. 1, 2010
Porsche 918 Spyder Fuel efficient when on the battery but probably the worst offender when on its V8. Green washing at its finest?
Porsche unveiled an ultra-efficient, low-emission, mid-engine super sports car featuring it own variant of hybrid and electric drive technology.
The 918 Spyder Concept combines high-tech racing features with an HEV-drivetrain offering some very unique attributes.
The vehicle is currently being designed to achieve a 78 mpgUS combined rating, higher than the Prius or most fuel efficient European Diesel yet will offer the performance of a super sports car with acceleration from a standstill to 60 mph in just 3 seconds, top speed of 198 mph, and faster than the Porsche Carrera GT at Nurburgring.
This is not achievable when driving around on its 500 HP V8 however!
The 918 Spyder is one of three Porsche models with an HEV drivetrain making their world debut at the 2010 Geneva Motor Show. This trio made up of Porsche's new Cayenne S Hybrid SUV with parallel full-hybrid drive, the 911 GT3 R Hybrid race car with electric drive on the front axle and a flywheel mass battery (KERS), and the two-seater high-performance 918 Spyder mid-engined sports car with PHEV technology clearly demonstrates not only the great bandwidth of this new drive technology, but also the innovative power of Porsche as a genuine pioneer in performance hybrid drives.
A race-bred V8 engine with an HEV drive
This open two-seater is powered by a high-revving V8 developing more than 500 HP and a maximum engine speed of 9,200 rpm as well as electric motors on the front and rear axle with overall mechanical output of 218 HP.
The V8 combustion engine is the next step in the evolution of the highly successful 3.4-liter power unit already featured in the RS Spyder racing car and positioned mid-ship, in front of the rear axle, giving the car excellent balance and the right set-up for supreme performance on the race track.
Power is transmitted to the wheels by a seven-speed Porsche-Doppelkupplungsgetriebe (PDK) transmission that feeds the power of the electric drive system to the rear axle. The front-wheel electric drive powers the wheels through a fixed transmission ratio.
The energy reservoir is a fluid-cooled Li-Ion battery positioned behind the passenger cell. The big advantage of a plug-in hybrid is that the battery can be charged on the regular electrical network. A further point is that the car's kinetic energy is converted into electrical energy fed into the battery when applying the brakes, thus providing additional energy for fast and dynamic acceleration.
Four distinct driving modes
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 allowing a range of up to 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), when overtaking or for even better performance.
With the hybrid drive system offering this wide range of individual modes and applications, the 918 Spyder is able either to achieve lap times comparable to those of a thoroughbred racing car, or the extremely low emissions and high fuel economy figures of a plug-in hybrid.
Advanced body structure
Like the drivetrain, the lightweight body structure of the Porsche 918 Spyder also bears out the car's DNA carried over directly from motorsport: The modular structure with its monocoque bodyshell made of carbon-fiber-reinforced plastic (CFP) and liberal use of magnesium and aluminum not only reduce weight to below 3,285 lb while also ensures supreme driving precision due to a high level of torsional stiffness.
Reminiscent of highly successful, legendary racing cars such as the Porsche 917 and the current Porsche RS Spyder, the 918 Spyder, with its design concept so typical of Porsche arouses powerful emotions. The combination of racing car dimensions, clearly structured design with perfectly balanced surfaces, and innovative details throughout, creates an ideal synthesis of form and function following Porsche's design DNA.
Variable aerodynamics ensures both visionary and traditional highlights especially around the rear spoiler. The striking rear hoods extending out of the headrests, in turn, not only fulfill an aerodynamic function on the 918 Spyder, but also accommodate retractable air intakes with a ram air function.
High-tech interior
The driver and passenger both enjoy contoured sports bucket seats. Additionally, the cockpit offers a glimpse at the potential interior architecture of future Porsche super sports cars. The three free-standing circular dials for road speed (left), RPMs (middle) and energy management (right) would appear to come directly from a racing car in the '60s, bearing out that unique philosophy of driver orientation so characteristic of Porsche.
The center console rises up towards the front in the 918 Spyder and houses a touch screen for intuitive control of the car's functions, serving to reduce the number of visible controls and maintain the principle of direct operation.
The control units relevant to the driver are mainly concentrated on the three-spoke multifunction sports steering wheel, while the variable driving modes are supplemented by a switch enabling the driver to call up various drive programs and serving as the push-to-pass button for E-boosting. Instrument illumination, finally, varies from green for the consumption-oriented running modes to red for the performance-oriented driving programs.
The Porsche 918 Spyder concept also comes with further innovative functions such as the Range Manager. After being activated in the Center Display, the Range Manager uses the map in the navigation system to present the remaining range the car is able to cover, naturally allowing the driver to influence that range through the appropriate choice of power and performance.
In cities with environmental alert areas, the Range Manager states whether the driver is able to reach a certain destination on electric power alone.
Applying this information and using further info on the availability and location of special energy filling stations, the driver is then able to choose his personal style of driving as well as the right battery charge and filling strategy.
Offering a unique combination of low fuel consumption, supreme performance and long electric range, the Porsche 918 Spyder concept represents an essential milestone in Porsche's strategy on the way to genuine electric-mobility.
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