Safer, More Pleasurable Driving On Snow And Ice: The Mercedes-Benz GLK 4MATIC Gets To Grips With Winter
STUTTGART/HOCHGURGL – December 9, 2008: Soon it will be time to head for the ski slopes again, and drivers of Mercedes models with the permanent all-wheel-drive system 4MATIC can rest assured as they set off en route to their chosen winter paradise. Because the performance of the drive configuration on roads affected by snow or ice is truly impressive. Mercedes-Benz is demonstrating the high traction reserves coupled with excellent directional stability and safety in the new GLK at its 4MATIC workshop. In extreme winter conditions at a height of 2500 metres on the Austrian Timmelsjoch High Alpine Road this compact SUV is demonstrating that its driving dynamics really are in a class of their own.
As is the case with 4MATIC’s fine-tuning on a dry or wet road, directional stability and therefore the active safety of the GLKmodels is always to the fore when wintry conditions prevail, too. The basic 4MATIC mechanism with a 45:55 percent torque split between the front and rear axles along with the multiple-disc limited-slip centre differential with a basic locking torque of 50 Nm adds up to an ideal solution. This basic design delivers high traction since, on the one hand, the dynamic shift in axle load toward the rear axle that occurs during acceleration is used to deliver more drive torque to the rear. Meanwhile, the multiple-disc limited-slip centre differential can also variably shift the drive torque from 30 to 70 or 70 to 30 percent between the front and rear axle, whenever the road conditions so dictate. As such, the electronic control systems ESP, 4ETS or ASRcan intervene as late as possible; the bulk of the torque is converted into traction on slippery roads.
All interventions go virtually unnoticed, but the drivers are still informed immediately if they are driving on the limit. In this case a yellow warning light flashes in the instrument panel – a clear signal to adjust their driving style to the road conditions. The arrangement featuring a permanent design mechanism has key advantages over other systems that first need to diagnose a lack of traction before activating their 4x4 all-wheel drive. The 4MATIC on the GLKwill have already made use of this valuable time to transmit drive torque via the wheels to the road.
4ETS: integrated “automatic start-off aid” for ice and
snow
When pulling away in wintry conditions the engineers use the
off-road algorithms on the GLK4MATIC to develop optimum traction. Certain
road conditions are automatically detected and the interventions of the
4ETS electronic traction control system adjusted so that as much
acceleration as possible can be achieved with minimal wheel slip, providing
optimum directional stability in the process. This strategy also allows the
vehicle to pull away under adverse conditions, such as when one side of the
vehicle is on an icy slope (the so-called µ-split) or both wheels on the
front or rear axle have limited grip (µ-jump). Stable conditions on wintry
roads
On winding roads covered with snow and ice, vehicle stability is primarily controlled by means of engine torque regulation in the acceleration skid control system ASR. Taking into consideration the longitudinal and lateral dynamics of the vehicle continuously determined by the ESP sensor system, the ASRcontrol thresholds are adjusted according to the driving situation. In order to ensure stable driving conditions, on winding roads the longitudinal force must be controlled via engine torque regulation in such a way that sufficient lateral force is always available. In order to comply with this law of physics, when driving on winding roads the control thresholds for engine torque regulation on the outer wheels are reduced considerably at low frictional coefficient, ensuring that the tyres can develop sufficient lateral force.
4MATIC: top performance in all areas
The 4MATIC drive system
in the GLKis among the most powerful all-wheel-drive systems there are; its
control systems break new ground. Advantages over other systems with a
transversely installed drive unit are achieved thanks to the basic compact,
light and friction-loss-optimised design with its longitudinally positioned
engine and integrated main and transfer case. Fuel consumption, for
example, is at the same level as that of a comparable, conventionally
driven vehicle, whilst noise and vibration levels are on a par with those
in higher vehicle categories.
105 years of all-wheel-drive technology from Mercedes-Benz
The history of all-wheel drive from Mercedes-Benz begins way back in 1903,
when Paul Daimler, the son of the company’s founder, creates the
foundations for designing vehicles with all-wheel drive. Since then the
accepted maxim has been that all-wheel drive is the number-one technology
for making better and safer progress on poor roads. As the decades pass it
is successfully introduced in a variety of Mercedes-Benz vehicles, in both
passenger cars and commercial vehicles. Some models, such as the G-Class
and the Unimog, have attained legendary status all over the world. But
all-wheel drive has its benefits in everyday driving on asphalt roads too,
as demonstrated by the saloons and sports utility vehicles (SUV) from
Mercedes-Benz.
4MATIC available in no less than 51 Mercedes models
The
Mercedes-Benz all-wheel-drive line-up includes nine model series and offers
an broad range of options: starting with the C-Class and E-Class, both
available as saloon and estate versions with 4MATIC, through the S-Class,
the luxury CL Coupé and the R-Class touring SUV, the Stuttgart-based
manufacturer offers the compact GLKSUV as well as the GL-Class and M-Class
off-roaders. The evergreen G-Class off-roader, which really comes into its
own off the beaten track, will be celebrating 30 years of loyal service
next year. It has a reputation as being one of the world’s best
cross-country vehicles and is just one of 51 passenger car models which
Mercedes-Benz offers with permanent all-wheel drive.