“Porsche Intelligent Performance” is all the rage in Zuffenhausen these days. The company has been touting its green energy credentials for the last few years, introducing hybrid versions of the Cayenne, Panamera, a 997 GT3-based hybrid race car, the 918 Spyder hypercar and the 919 Hybrid Le Mans racer. Even a hybrid variant of the venerable 911 is likely.
Students of Porsche history, however, will recall that a Porsche-designed hybrid is actually very old news: Professor Ferdinand Porsche himself designed the Lohner-Porsche Mixte gasoline-electric hybrid at the turn of the 20th century.
Current government fuel economy regulations and tax incentives in the U.S. and Euro Zone have compelled many auto manufacturers to offer gasoline-electric hybrids to the general public. However, the modern hybrid vehicle is the result of compromise.
Electric motors offer excellent efficiency and instant torque that is available from near zero rpm. Purely electric vehicles, however, have a limited driving range due to the constraints of current battery technology. Modern gasoline engines are woefully inefficient, converting less than 15 percent of potential fuel energy into motive force (the rest is wasted due to frictional losses, heat loss to the cooling system and exhaust and combustion inefficiency).
In theory, combining an internal combustion engine with one or more electric motors offers the best of both worlds, blending the instant torque and economy of electric drive with the range and extra high-speed acceleration that is possible with a gas engine. In practice, it is a challenge for automakers to package all the necessary electronics and battery packs into existing chassis. There is also the question of whether hybrid drivetrains yield enough of an improvement in efficiency over modern direct injection diesel and gasoline engines to justify their additional weight, cost and complexity.
Though the gasoline-electric hybrid may not be the ultimate solution for curtailing fossil fuel consumption or moving the auto industry towards perpetual sustainability, Porsche and others are utilizing the technology in a compelling manner to boost the performance and economy of already potent models.