How Subaru wants to make gasoline engines more economical with air injection

Gasoline engines love air. That’s why they are so happy when you install a turbo or supercharger. Subaru now comes with another special innovation: air injection. But this is not intended to increase power. Carbuzz discovered one patent from Subaru, which explains how the brand wants to make the gasoline engine more efficient with air compressors.

In the combustion chamber of the engine, where the piston goes back and forth (not up and down, because it is a boxer engine), there is a kind of pimple near the fuel injector. Inside this pimple is a small extra chamber with an injector that can blow air into the engine. There are holes in the pimple so that excess air can escape and enter the combustion chamber.

The air injection hits the clean cylinder walls

When the engine is cold, oil sometimes sticks to the cold walls of the cylinders. This is not conducive to optimal combustion and causes more emissions. By blowing air slightly at a right angle, vortices are created that blow this sticky oil away from the cylinder walls. This fuel burns better, which makes the engine more efficient.

One of the drawings from the patent | Image: © US Patent and Trademark Office / Subaru

We hear you thinking: how much of an impact on emissions can a good winter start have? Maybe not so much with a conventional combustion engine, because it reaches a good temperature after fifteen minutes. But with a hybrid or plug-in hybrid, the engine doesn’t always get a chance to warm up properly, because the gasoline engine is often turned off while the electric engine is running.

When will the Subaru air injection arrive?

Air injection can also be used to add a little air to the fuel mixture, for example (temporarily) making the car run less. It remains to be seen if Subaru will use the technology for future engines. Car brands frequently apply for patents for inventions they won’t use themselves. We will see it live.