What is the purpose of rev-matching during downshifting?

[ChaseRose]

As the name suggests, rev-matching during downshifting involves "giving a little extra throttle" while downshifting to eliminate the speed difference between the engine and the transmission, ensuring that the engine speed matches the gear as closely as possible. This helps reduce the jerking sensation during downshifting. If the vehicle speed and gear are not matched, the meshing of gears during shifting can cause vibrations, leading to that jerking feeling. Additional info: When performed correctly, rev-matching does not harm the vehicle; in fact, it can reduce clutch wear to some extent. It's important not to give too much throttle during rev-matching—avoid pressing the accelerator too hard, as excessively high engine RPMs can cause the car to lurch forward. Rev-matching is a driving technique that requires practice to master for smooth downshifts.