Synchronizer speeds up. Santana 3000 gearbox has added 1 synchronizer, which can obviously improve shift smoothness and speed up. One of the so-called technical improvements of 3000 is its frequency conversion air conditioner, which claims to have several characteristics such as energy saving and independent circulation function. In any case, the external circulation can be turned on or off under any working conditions to isolate unclean air. There are measured cooling curves of Santana 2000 and overtaking under different working conditions.