What do Volkswagen's TSI and FSI mean?

FSI refers to in-cylinder direct injection engine, which adopts fuel stratified combustion technology. The so-called stratified injection is based on direct injection technology. In short, the oil is injected once in the intake stroke. The mixture formed at this time is very thin (25: 1), and the spark plug cannot be ignited. Therefore, the oil will be injected again in the compression stroke. At this time, the mixer is rich (12: 1) and can be ignited. In China, because of the quality of petroleum products, FSI only stands for in-cylinder direct injection.

TSI refers to stratified injection of dual supercharged fuel. Mechanical supercharging uses the engine's own power to compress air, and turbocharging uses the exhaust energy in the exhaust system to drive the turbine. Turbocharging has a slow response when the engine speed is low, and there is a hysteresis phenomenon, while mechanical supercharging consumes more engine power when the engine speed is high, so using double supercharging can realize complementary advantages. Note: Domestic Shanghai Volkswagen and FAW-Volkswagen TSI have eliminated supercharged and stratified fuel injection, and only have turbocharged and in-cylinder direct injection engines.

TFSI is a turbocharged engine (T) of FSI, and its supercharging degree is lower than that of TSI. TFSI and TSI in China have only two technologies, one is turbocharging and the other is in-cylinder direct injection. However, in order to highlight the high-end than Volkswagen, Audi will slightly increase the power of several kilowatts in the training, causing a different illusion.