Mercedes-Benz is a successful 4×4 manufacturer in the premium segment, and the 4MATIC drive configuration’s performance on snowy and icy roads plays a significant part in this market success:
it delivers high traction reserves, excellent driving stability, optimum safety and a supreme level of comfort. As is the case with the 4MATIC tuning on a dry or wet road, driving stability, and therefore active safety are always to the fore in wintry road conditions.
The C-Class’s 4MATIC range encompasses five variants: the top saloon model is the C 350 4MATIC BlueEFFICIENCY with the new V6 petrol engine (225 kW/306 hp) and the current 7G-TRONIC PLUS automatic transmission, and two diesel models, both available as a saloon and estate: the C 250 CDI 4MATIC BlueEFFICIENCY (150 kW/204 hp) – from June 2011 also available with 7G-TRONIC PLUS) and the C 300 CDI 4MATIC BlueEFFICIENCY (170 kW/231 hp) – available from June 2011), both fitted as standard with the seven-gear automatic transmission 7G-TRONIC.
The mechanical foundations of 4MATIC with its torque distribution of 45 to 55 percent between the front and rear axle and the plate-type differential lock in the central differential with a basic locking effect of 50 Nm offer optimum conditions. This basic conception facilitates high traction values. The system is ably supported by 4ETS – a component of ESP, which replaces the function of a lock through targeted brake actuations at the spinning wheel.
Intervention by the electronic control systems ESP, 4ETS or ASR can occur as late as possible and the bulk of the drive torque is converted into tractive power, even on slippery roads. All the control intervention functions are performed virtually unnoticed, though the driver is informed immediately if they approach the critical limits. In this instance a yellow warning symbol flashes in the instrument cluster, clearly signalling that the driving style should be adapted in line with the road conditions.
The drive mechanism‘s permanently engaged design offers key advantages over other systems that first need to diagnose a lack of grip before activating the all-wheel drive. The 4MATIC system on Mercedes-Benz models will have already made use of this valuable time to start transmitting drive torque via the wheels to the road.
Source: Daimler AG