Shedding the kilograms to drive better
Shifting over to the mechanical side of an AWD system, Mercedes-Benz engineers decided to use a fixed drive ratio between front and rear. Because a Mercedes has traditionally been a rear-wheel-drive car, 60% of power goes to the rear and 40% to the front. Engineers felt that maintaining some bias to the rear was necessary to keep from totally changing the way their cars handled.
By using a fixed ratio system with electronic controls, engineers were able to reduce the weight of the system significantly. Incorporating the transmission and extra drive into a single case was a good first step, but a fixed ratio system allowed engineers to delete the centre clutch pack and extra fluids from the system.
Electronically controlling wheel slippage let engineers delete the differential clutch packs (which normally control wheel slippage) as well as reduce the size and weight of drive shafts, differentials, axles and axle housings.
When you put both the mechanical and electronic systems together, the 4th generation of 4MATIC has a total weight of between 50 and 75 kilograms (110 and 165 lb) depending on the model of vehicle the system is installed in. It is this total weight, which is significantly less than other systems, that keeps fuel economy in line and drivers feeling secure and comfortable.
Shifting over to the mechanical side of an AWD system, Mercedes-Benz engineers decided to use a fixed drive ratio between front and rear. Because a Mercedes has traditionally been a rear-wheel-drive car, 60% of power goes to the rear and 40% to the front. Engineers felt that maintaining some bias to the rear was necessary to keep from totally changing the way their cars handled.
By using a fixed ratio system with electronic controls, engineers were able to reduce the weight of the system significantly. Incorporating the transmission and extra drive into a single case was a good first step, but a fixed ratio system allowed engineers to delete the centre clutch pack and extra fluids from the system.
Electronically controlling wheel slippage let engineers delete the differential clutch packs (which normally control wheel slippage) as well as reduce the size and weight of drive shafts, differentials, axles and axle housings.
When you put both the mechanical and electronic systems together, the 4th generation of 4MATIC has a total weight of between 50 and 75 kilograms (110 and 165 lb) depending on the model of vehicle the system is installed in. It is this total weight, which is significantly less than other systems, that keeps fuel economy in line and drivers feeling secure and comfortable.
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| Photo: Mercedes-Benz |