What is the purpose of downshifting?

Downshifting primarily serves to provide more power for acceleration when needed. When a driver downshifts, they shift from a higher gear to a lower gear, which allows the engine to operate at a higher RPM. This increased engine speed can deliver more torque and power to the wheels, facilitating quicker acceleration.

In scenarios where a vehicle requires more power, such as when merging onto a highway or navigating a steep hill, downshifting effectively enhances performance. It also helps maintain optimal engine performance and responsiveness, as lower gears allow for better utilization of available power.

The other options focus on disengaging the engine, increasing vehicle speed through other means, or decreasing engine RPM, which do not accurately capture the primary purpose of downshifting in manual transmission vehicles. The intent behind downshifting is to enhance acceleration and power, making it a critical technique in effective manual driving.