FSI, or Fuel Stratified Injection, is the state-of-the-art in fuel injection technology available on the Leon's top petrol engine. It increases both torque and power while improving consumption (up to 15%) and reducing exhaust emissions.

As opposed to standard manifold injection systems, FSI engines inject fuel directly into the cylinder and use a specially shaped piston crown to concentrate the air/fuel mix below the sparkplug.

This produces optimal fuel combustion which, in turn, reduces heat loss and increases output while minimising fuel consumption and emissions.