4MATIC all-wheel drive for compact models.
Integrated in an innovative way.
The most innovative components of the new 4MATIC for compact models include the output shaft to the rear axle integrated into the seven-stage automated 7G-DCT dual clutch transmission, and the differential with an integrated, electrohydraulically controlled multi-disc clutch. This enables fully variable drive torque distribution between the front and the rear axle. The performance flow to the rear powertrain is carried out by a compact power take-off unit (PTU), which is fully integrated into the main gearbox and is lubricated via its oil system. Additional benefits of this design are a lower system weight than is available from the competition, and high efficiency. All 4MATIC models are outstanding, as are the front-wheel-drive versions with good energy efficiency.
The 4MATIC all-wheel drive is a completely new development and was designed specifically to coordinate with the new front-wheel drive models.
Fully variable drive.
Fully variable torque distribution is ensured by the electrohydraulically operated multi-disc clutch integrated into the differential. The basic principle is that if the multiple-disc clutch is disengaged, the front axle drives the vehicle almost entirely. If the multi-disc clutch is engaged, the rear axle comes into play. However, drive torque distribution can be variably shifted between the front and rear axles depending on the situation (torque on demand). The rotor-type pump integrated into the differential provides the operating pressure to activate the rear axle within milliseconds. The pump is automatically activated by slight rotational speed differences between the front and rear axles, and a proportioning valve adjusts the pressure.
The actuation of the new 4MATIC follows the basic principle of “as often as necessary, as seldom as possible”. If circumstances allow, the all-wheel models are driven almost entirely in the highly economical front-wheel drive mode. If the driving situation demands, drive torque is rapidly adjusted at the rear axle. However, as soon as additional torque on the rear axle is no longer required, for example in the case of strong braking where the ABS comes into play, the rear drive train is deactivated and the torque reduced to zero. If there is a risk of understeering or oversteering under load, the torque is first distributed so that the vehicle is stabilised again. If this is not enough to stabilise the vehicle, the ESP® or 4ETS control systems, which are adapted to 4MATIC operation, help to keep the vehicle on course.
With this strategy, the developers have combined optimum efficiency with top vehicle dynamics and driving safety.
Individually adjusted - made for performance.
The powerful AMG versions for compact models fulfil the highest standards of engine technology and power transmission. Whilst the performance-oriented AMG 4MATIC all-wheel drive was being developed, the focus was on the concepts of “performance” and “dynamics”. The adaptation of the 4MATIC control system for the AMG versions is based on 3-stage ESP®. The torque distribution depends on the activated gearshift program of the 7G-DCT dual clutch transmission. In the ECO program, the rear axle is provided with less torque, so that the handling seems gentler and supports an economic driving style with lower revs.
In the SPORT or MANUAL modes, the activation times are shorter and more torque is transferred to the rear axle to help provide for a dynamic and sporty driving style. In this way, the individual drive programs support the driver's personal style of driving.