What is the button at the bottom of the accelerator pedal in a Mercedes-Benz C-Class?

[SanJonathan]

This button is the forced downshift switch, which automatically triggers the downshift function when the accelerator pedal is fully depressed for acceleration. Through the computer's calculation, it automatically downshifts by 1 or 2 gears from the current gear, resulting in higher engine RPM and greater torque output, thereby enabling rapid acceleration or overtaking. The English name for this button is "kickdown". Using "Kickdown" results in an extremely aggressive response from the car. Theoretically, this method of rapidly downshifting to significantly increase torque can instantaneously improve vehicle acceleration, making it theoretically feasible for overtaking. However, nothing is absolute. Some automatic transmission models have a very sluggish "Kickdown" design. Even if the "Kickdown" button is triggered by fully depressing the accelerator, there is a lag in response time. For such models, using "Kickdown" for overtaking is clearly less effective than simply applying heavy throttle without triggering the Kickdown mode.