Automotive transmission is a set of transmission devices used to coordinate the speed of the engine and the actual speed of the wheel to play the best performance of the engine. The transmission can produce different speed ratios between the engine and the wheels while the car is moving. The advantages of the manual transmission are simple structure, reliable performance, low manufacturing and maintenance costs, and high transmission efficiency (theoretically more fuel efficient), in addition, because of the pure mechanical control, the shift response is fast, and can more directly express the will of the driver, so it is also more fun to drive.