A.1~4 B.4~7 C.7~10 D.10~13
A.0.001~0.005 B.0.005~0.01 C.0.01~0.015 D.0.05~0.1
A.使用腳剎 B.逐檔減擋 C.跳檔減擋 D.打倒檔