Porsche 918 Spyder
he 918 Spyder is a mid-engined two-seater sports car designed by Michael Mauer. It is powered by a 4.6 litre V8 engine. The engine is built on the same architecture as the one used in the RS Spyder Le Mans Prototype racing car without any engine belts.
The engine weighs 140 kg according to Porsche and it delivers 608 horsepower (453 kW) at 8,500 rpm and 528 N·m (389 lbf·ft) of maximum torque. This is supplemented by two electric motors delivering an additional 279 hp (208 kW). One 154 hp (115 kW) electric motor drives the rear wheels in parallel with the engine and also serves as the main generator. This motor and engine deliver power to the rear axle via a 7-speed gearbox coupled to Porsche's own PDK double-clutch system. The front 125 hp (93 kW) electric motor directly drives the front axle; an electric clutch decouples the motor when not in use. The total system delivers 887 hp (661 kW) and 1,275 N·m (940 lbf·ft) of torque. As of October 2012 the engineering design is not finalized, but Porsche has given performance figures of 0–100 km/h (62 mph) in 2.8 seconds, 0-200 km/h (120 mph) in 7.9 seconds and a top speed of more than 340 kilometres per hour (210 mph). The energy storage system is a 6.8 kW·h liquid-cooled lithium-ion battery positioned behind the passenger cell. In addition to plugging in to recharge, the batteries are also charged by regenerative braking and by excess output from the engine when the car is coasting. CO2 emissions are 79 g/km and fuel consumption is 3.3 L/100 km (94 imperial mpg/78 us mpg).
The 918 Spyder offers five different running modes: E-Drive allows the car to run under battery power alone, using the rear electric motor and front motor, giving a range of 20 miles (32 km); the car can reach 93 mph (150 km/h) in this mode. Three hybrid modes (Hybrid, Sport and Race) use both the engine and electric motors to provide the desired levels of economy and performance. In Race mode a push-to-pass button initiates the Hot Lap setting, which delivers additional electrical power. The chassis is a carbon-fibre-reinforced plasticmonocoque. Magnesium and aluminium are extensively used in the construction of the car which helps keep the 918 Spyder's weight down to 1,640 kilograms (3,620 lb).
On July 28, 2010, after 2000 declarations of interest, the Supervisory Board of Dr. Ing. h.c. F. Porsche AG, Stuttgart, gave the green light for series development of the Porsche 918 Spyder.