Working the levers
Once you do pull back the curtain and see the real source of the show, you're no less impressed. For all of the erstwhile magic happening from your viewpoint behind the wheel, the reality of the situation is no less magical. Porsche's engineers have taken a brilliant, raucous 9,150-rpm Le Mans P2 prototype V-8 engine and opened it up just a bit, then stuck it--and its tailpipes--right behind your ears. Romp on the loud pedal and things get fun in a hurry.
Those same engineers have also worked in a pair of electric motors, one at the rear, and one at the front. The electric motor at the rear helps to drive the rear wheels whenever called upon, or does it on its own in electric mode. At the front, another electric motor lies just aft of the front axle, but with a twist: it's completely decoupled from the powertrain bits at the rear. That's right, that front motor is all on its own, running in sync with the rear through some NASA-grade wizardry at speeds up to 165 mph. After that, the 918 Spyder becomes rear-drive only.
Underlying all of the powertrain synchronization is a single-mode traction and stability control system, ready to handle everything from a gravel-strewn mall parking lot to a 140-mph apex. It's so well-tuned that we never once felt it intrude on our fun, even when we were testing the limits on track--it will let you slide, countersteer, apply throttle to correct yaw, and more. Part of the magic here is the torque vectoring enabled by the electric motors on each axle. Sophisticated electronics apply more power, rather than stealing power or applying brakes, to help match the car's course to your intended arc.
It's simply a very good stability control system. It wouldn't be a good stability control system at all if you couldn't turn it off, but you can--not that you'd ever really want to, unless it were to shred some rear tires.
2015 Porsche 918 SpyderEnlarge Photo
Tying it all together is a set of five modes that alter the character of the 918 Spyder significantly. Accessed through the knob at the four o'clock position on the steering wheel, the modes are: E-Power, Hybrid, Sport Hybrid, Race Hybrid, and, with a press of the central red button while in Race mode, Hot Lap mode.
E-Power (electric) mode does just as you'd expect, siphoning off the car's 6.8-kilowatt-hour supply of electrons to supply a maximum of 230 kW of power to the two electric motors for a maximum range of up to 19 miles (not coincidentally, about the distance from Weissach to Zuffenhausen), or about 12 miles in more normal driving conditions. A Jetson's-like whine accompanies the all-electric mode, louder at lower speeds, then slowly subsumed by the susurrus of the wind over the cabin. You might think the 918 Spyder would feel a bit sluggish in electric mode, but you'd be wrong; and if you need to accelerate more quickly than electric mode will allow, give it the boot, and the car will automatically kick on the throaty V-8 and send you into Hybrid mode.
Hybrid mode is likely the setting most drivers will use most often, leveraging the extra power of the electric side of the drivetrain, while also taking every opportunity to turn off the gasoline V-8 and top up the battery packs through regenerative measures, thus maximizing efficiency. It's a seamless, easy-going mode that feels the most like driving an ordinary car. There's plenty of pep whenever you'd like it, but the 918's around-town manners are impeccable in Hybrid mode.
2015 Porsche 918 SpyderEnlarge Photo
Opt for Sport Hybrid mode and the car becomes just a bit more aggressive on throttle application, feeling more eager to leap forward with each millimeter of the pedal's sweep. The V-8 stays on continuously in this mode, enhancing performance through application of the electric motors' power at ideal points in the rpm band.
Race Hybrid mode kicks everything up a notch further, from the use of the combustion engine to the rate of recharge of the battery packs--after all, they need to be charged to deliver full electric boost. The PDK dual-clutch gearbox is also tuned for faster shifts, and the system extracts the maximum power output from the electric motors.
Hot Lap mode takes it to the extreme of the 918 Spyder's abilities, pushing to the absolute limits of the battery and electric motors, tapping all of the available energy for the fastest single lap time possible.