More power from every drop of petrol Audi FSI technology

FSI technology increases the torque and output of petrol engines, makes them up to 15 percent more economical and paves the way for low exhaust emissions. Thanks to the dimensions and harmonisation of the combustion chamber design, the airflow and the injection rate, direction, timing and pressure, this innovative principle squeezes more power out of every drop of petrol.

With FSI technology, fuel is injected directly into the combustion chamber. The injector regulates the amount of fuel with millisecond precision at injection pressures of between 30 and 110 bar. During the injection process, the evaporating fuel has a significant cooling effect on the cylinder charge. On the one hand, this contributes to improved cylinder charging, meaning that the engine output is duly enhanced. On the other, the engine’s tendency to knock is reduced by the cooling effect. This reduction means that the compression ratio of FSI engines can be set considerably higher than for engines with conventional injection systems.

The engines of the FSI family are fitted with a two-stage variable intake manifold. The power mode (short duct length) at high engine speeds contributes to the high specific power output of the engines. At low revs, the “long duct length” is selected instead, increasing the maximum torque by more than 15%.

With the aid of a flap system in the intake duct, the in-cylinder flow can be optimally adjusted. In part-load operation, a strong flow ensures low fuel consumption and low exhaust emissions. At full load, the air is drawn in with minimal losses, meaning that torque and output are increased.