So, what is Porsche’s 6 stroke engine all about?
2 stroke? 4 stroke? In a typically innovative manner that could possibly reshape the future of internal combustion engines, Porsche has filed a patent for a revolutionary six-stroke engine design.
PORSCHE
Collaborating with the Technical University of Cluj-Napoca, the German automaker introduces an innovative system dubbed "Method for a Combustion Machine With Two Times Three Strokes." This engine concept is a hybrid of the traditional four-stroke and two-stroke engine designs, offering the potential to increase both power and efficiency while reducing emissions.
PORSCHE
A typical four-stroke engine operates with intake, compression, power, and exhaust strokes, achieving one power stroke every two revolutions. In contrast, Porsche's six-stroke design allows for two power strokes within just three revolutions. The system relies on a unique crankshaft configuration that operates on a planetary gear system, enabling variable compression and stroke lengths.
U.S. Patent and Trademark Office
In Porsche's design, the first three strokes follow the familiar four-stroke cycle—intake, compression, and power (ignition/expansion). The key innovation lies in what happens next: at the bottom dead center of the first power stroke, scavenging ports open, allowing fresh air to be forced in and pushing out most of the exhaust gases. On the next upstroke, the engine compresses the mixture of fresh air and residual exhaust gases, with fuel injected directly. The second power stroke occurs after this compression, before the cycle completes with traditional exhaust and intake strokes.
U.S. Patent and Trademark Office
By delivering two power strokes for every three revolutions, the engine generates more power. Moreover, the added compression phase ensures a more complete combustion of the fuel, resulting in cleaner emissions. This design operates similarly to how exhaust gas recirculation systems reduce emissions, but without the need for complex exhaust systems.
Thermal efficiency, one of the key metrics of engine performance, could improve dramatically. While traditional four-stroke engines typically achieve 30% thermal efficiency, the six-stroke engine’s design has the potential to reach 50%, making it far more efficient.
U.S. Patent and Trademark Office
The six-stroke engine could have a profound impact on performance vehicles, offering a mix of increased power, improved fuel efficiency, and reduced emissions. With power delivered more frequently, it could enhance the throttle response of performance cars like Porsche's 911, though the added complexity may introduce challenges related to engine vibration and durability in high-revving applications.
U.S. Patent and Trademark Office
The patent filing, however, leaves open many questions. Porsche has yet to confirm whether this design will enter production, and it is unclear how the additional mechanical complexity will affect manufacturing costs and long-term reliability.
U.S. Patent and Trademark Office
Porsche has been at the forefront of sustainable automotive technology, particularly with its work on eFuels, which are carbon-neutral synthetic fuels. The six-stroke engine could align with these efforts, allowing Porsche to continue refining internal combustion engines in a way that supports sustainability. While electrification continues to dominate the conversation around the future of mobility, Porsche's innovations in internal combustion could provide a viable bridge to a cleaner automotive future.
Porsche’s six-stroke engine represents a bold step forward in internal combustion technology. With its potential for increased power, improved efficiency, and reduced emissions, it might give traditional four-stroke engines a serious challenge, preserving the legacy of combustion engines in the era of electrification. If it works, perhaps it will replace four-stroke engines altogether.
PORSCHE
