It's quite complicated, yet rather elegant.
At the heart of the beast are two power sources: a highly advanced, 2.0-liter, turbocharged V4 engine, and an 800-volt electrical system.
The electrical system uses kinetic energy recovered from braking and from the exhaust. That energy is fed into a centrally-mounted lithium-ion battery pack that, in turn, power an electric motor mounted on the front axle.
The driver chooses when to release the electrical energy via a button on the steering wheel, receiving a boost of 400 horsepower. Add in the 500 HP produced by the combustion engine, fed to the rear wheels, a total of 900 HP is on tap.
LMP1 regulations allow a maximum of 2.2 kilowatt hours, or 8 megajoules. Porsche was the first team to use that much power in 2015 and has been joined by Toyota this season. Audi still operates in the 6 megajoule class.
According to Porsche, lessons learned from the 919 will be applied to the upcoming Mission E electric car, which will also use an 800-volt electrical system.
After claiming wins at Silverstone and Le Mans, the #2 Porsche of Marc Lieb, Neel Jani, and Romain Dumas leads the World Endurance Championship points. The championship resumes this weekend at the Nurbugring, where Lieb headed the first practice session.