Why is it necessary to blip the throttle when downshifting?

[McClayton]

The purpose of blipping the throttle during downshifting is to synchronize the gears, ensuring smooth engagement without significant impact, eliminating jerking sensations, and preventing damage to the transmission sliding sleeve caused by excessive speed differences. Throttle blipping involves appropriately pressing the accelerator pedal while downshifting. When the vehicle needs to downshift, this action helps synchronize the gears, avoiding damage caused by the forced engagement of the transmission sleeve due to excessive speed differences. Throttle blipping is generally a driving technique used in the coordination between the engine and a manual transmission. When shifting from a higher gear to a lower one while maintaining the same vehicle speed, the engine needs to provide higher RPM to achieve suitable torque for the larger gear ratio. This is relatively easier to achieve in gasoline vehicles, while it is more noticeable in diesel vehicles, especially before climbing a hill. In such cases, it is necessary to press the clutch while appropriately applying throttle to engage the lower gear. Without applying throttle, the transmission gears may struggle to engage properly, leading to gear grinding and failure to shift, which can be particularly dangerous during uphill climbs. After completing the downshift, accelerating by pressing the throttle increases the vehicle speed, but due to reduced torque output, the acceleration is relatively slower. At the moment of downshifting, the engine RPM immediately increases while the vehicle speed remains unchanged, and due to the increased transmission ratio, the torque delivered from the engine to the wheels also increases.