Changing gears, or shifting, in a car is a simple concept, but timing has an impact on drivability and fuel efficiency. The Transmission Control Unit (TCU) will interpret driver demand by interfacing with sensors such as the clutch and accelerator. TCU precisely controls the gear shifts and axle of a car’s transmission system. Vehicle handling has been significantly improved by automatically controlling the transmission. TCUs are constantly expanding to improve the fuel efficiency and better torque control.