what is fsi engine
Wikicars, a place to share your automotive knowledge. Fuel Stratified Injection or FSI is a proprietary direct fuel injection system developed and used by Volkswagen AG, as well as its luxury subsidiary Audi.It was first introduced in 2000 when VW introduced the 1.4 litre direct-injected inline-four unit in the Volkswagen Lupo city car.verview. As is the case with all direct-injection systems, FSI increases the engine's power output while reducing fuel consumption simultaneously by as much as 15 percent. This is in large part to the stratified charge principle at part load.