Is Porsche Really Working On An 18-Cylinder Engine?

Porsche has developed numerous vehicles and engines over its history, but the company's famous flat-six engine has long represented the brand for most enthusiasts. The flat-six and Porsche 911 share a legendary reputation, but Porsche has had a lot of success with other engine types, including the flat-four in the modern 718 Cayman and several V8s. 

Some of these engines have been large in both displacement and ambition, like the flat-12 that powered the iconic Porsche 917 race car, or the Carrera GT's wild V10 engine from the 2000s. Now, though, rumors suggest that Porsche may be cooking up a new engine that would make the flat-12 and V10 look tame (and small) by comparison. 

A patent suggests the company is at least toying with building what would be one of the largest — and craziest — internal combustion engines in automotive history. The engine design could have up to 18 cylinders aligned in a "W" configuration, and could be fed by three turbochargers. All the automotive world has to go on is the patent filing, but the engine, and the potential car it may power, have nonetheless generated lots of speculation – even if this supposed W18 may never leave the drawing board.

Engines with more than 12 cylinders have always occupied pretty rarefied air, even before the current age of downsized four-pots. Only a handful of cars have used V16 engines over the decades, and many were never more than concepts or prototypes. An 18-cylinder engine would be even more extreme, and while a few automakers have entertained building them, none have ever been used in a production automobile. 

The number of cylinders alone would make this Porsche engine a big deal, but that's just the start, as the patent also shows the cylinders aligned in a true "W" configuration. The Volkswagen Group has produced W engines in the modern era, but those engines actually had four cylinder banks and were essentially made from two narrow V engines. The new Porsche design instead uses three separate cylinder banks, making it more akin to three inline-6 engines using one crankshaft. 

Notably, while the patent says the design will accommodate 18 cylinders, it could also work with fewer cylinders, even odd numbers. You could, then, have three five-cylinder banks for a W15 engine. Each cylinder bank can also have its own turbo, which would result in a tri-turbo configuration. 

Needless to say, a Porsche W18 engine — or any other Porsche W engine using this layout — would be a groundbreaking piece of engineering. However, we only have the 2024 patent for the design, and the company has not indicated that such an engine is officially in the works. Many interesting designs never get past the patent stage, and a patent filing is by no means confirmation that Porsche is actually building the engine behind the scenes.

However, it's fun to speculate about what sort of car the engine may power if it were ever to reach production. While Porsche unveiled its Mission S concept in October, it seems unlikely that the supercar would use such a large or unconventional engine. Instead, rumors suggest the production Mission S may use a new flat-layout, eight-cylinder engine.

Should Porsche's W18 engine ever become reality, it's more likely to power a genuine hypercar, something that would follow the Porsche 918 Spyder. Whether the W18, or an engine like it, even moves beyond the patent stage — let alone enters production — remains to be seen, but it's an enticing prospect all the same.