Do the letters at the back of the car have any practical significance?

TSI means stratified injection technology with double superchargers abroad, and refers to stratified injection technology with double superchargers (turbocharging and mechanical supercharging). At home, T stands for turbocharging and SI stands for direct fuel injection, instead of the abbreviation of T and FSI, and there is no stratified injection technology, because the domestic fuel quality is average and it can't meet the requirements of stratified injection. In China, we often see different TSI signs. Some are all red, some are "SI" red, and only "I" is red. But don't get me wrong, their technologies are different, just to distinguish different displacements. For example, the "SI" with the displacement of 2.0 and 1.8 is red, and the high-profile model or high-profile model in the 2.0TSI model uses a full red logo, then of course only the "I" with the displacement of 1.4 is red.

TFSI engine is also a direct injection turbine fuel engine, which can be said to be the combination of FSI engine and turbocharger. That is, turbocharger) +FSI. T, like T in TSI, stands for turbocharging technology, followed by FSI (fuel stratified injection engine) and S stands for "stratified injection". TFSI engine has both stratified injection and turbocharging, and is an upgraded version of TSI engine.

TDI is the abbreviation of English Turbo Direct ion, which means turbocharged direct injection diesel engine. In order to solve the inherent shortcomings of SDI (naturally aspirated diesel engine), people installed a turbocharger on the diesel engine, which greatly increased the intake pressure, and the compression ratio was generally above 10, so that a great torque could be achieved at a very low speed. Moreover, due to more complete combustion, the content of harmful particles in emissions was greatly reduced.

The oil supply action has been completely independent of the door and piston system, so ECU has more dominance. The lean combustion and the mixing ratio of more elements beyond the traditional injection theory can be realized. In-cylinder direct injection engine can enter ultra-lean mode under stable operation or low load.