Ferrari has filed a patent for a four-cylinder engine that uses an electric turbocharger fed by an exhaust-driven generator.

Not only would this engine be Ferrari's first four-cylinder for a road-going car, but the exhaust turbine and intake compressor components in its innovative-sounding turbo system would not be connected mechanically as they are in conventional turbo motors.

Instead, the exhaust turbine would spin an electrical generator whose juice would feed a battery pack tasked with powering the turbo's compressor wheel.

Electric turbocharging is not a new concept; Ferrari's innovation is instead the use of the exhaust stream to generate electricity rather than solely doing so with a generator driven by the gasoline engine.

Other recent electric turbo arrangements use an engine-driven mild hybrid system with a 48-volt electrical system.

Ferrari filed its patent with both the United States and European patent offices in early 2018, but both organizations published the application in mid-July. The patent provides no clues as to what type of vehicle the electric turbo might power.