In a further contribution to active safety and accident avoidance, Mercedes-Benz if fitting the new A-Class with disc brakes on the front and rear axles. The Mercedes engineers have adapted the diameter and thickness of the brake discs precisely to the improved performance credentials of the new car. For example, the front disc brakes of the A 150 and A 160 CDI measure 276 x 12 millimetres, giving them a diameter 16 millimetres greater than in the current A-Class. The powerful A 170, A 180 CDI, A 200 and A 200 CDI models are fitted with internally ventilated disc brakes (276 x 22 millimetres) at the front. The A 200 TURBO, meanwhile, comes equipped with 288 x 25-millimetre ventilated brake discs. A sensor on the right-hand calliper monitors brake pad wear, sending signals which are constantly analysed and assessed. If the thickness of the pads is reduced to a critical point, an indicator lamp lights up in the instrument cluster. The brake booster is another component to show a performance advantage over the outgoing model. The master brake cylinder of the 9-inch unit has a diameter of 23.8 millimetres (predecessor model: 22.2 millimetres).

Solid disc brakes with integrated duo servo brake for the parking brake function re-place the rear drum brakes of the outgoing model in all engine variants of the new Mercedes compact car.

An overview of the brake data for the new A-Class: