Mercedes-Benz 4MATIC: All-wheel drive for all – in every class

Don't Copy From This Blog...

Each year during winter time, Mercedes-Benz heads over to the icy cold Hochgurgl resort in the Austrian Alps along with its fleet of off-road competent and capable vehicles equipped with the revolutionary 4MATIC traction system. In 2012, the Germans deployed their new CLS Shooting Brake, GL and GLK models to take a journey on the snow-covered alpine roads. Moreover, this event also served as a preview for the new addition in the compact class lineup: the CLA, which celebrates its world premiere in January 2013 at NAIAS Detroit.

With this occasion, Mercedes-Benz took the challenge to emphasize the versatility of the state-of-the-art 4MATIC all-wheel-drive system, which can be easily adapted across the entire range of models that wear the Star, from the A-Class and CLA-Class up to the classic G-Class, going through the C-, E-, S-, CL-, CLS-, GL-, GLK-, M- and R-Class. The introduction of the new version that was specially developed for compact-sized, front-driven vehicles heralds the advent of the new A 45 AMG performance hatchback, as well as the advent of the new CLA 45 AMG super 4-door coupe, both slated to arrive next year.

Check out more details and pictures through following the next links:

- The summit of perfection with new 4MATIC: All-wheel drive for all – tailor-made solutions

- 4MATIC for the compact model range from Mercedes-Benz: Greater driving dynamics, greater traction, greater safety

- On track of CLS and Co.: 2013 premiere for CLA and CLA 45 AMG

- Elegant in all weathers: the CLS 4MATIC Shooting Brake in the snow

- The new GL- and GLK-Class: Effortless superiority on- and off-road

Enjoy! :)

Copyright © 2012, mercedesgla. All rights reserved.

Read More

4MATIC for the compact model range from Mercedes-Benz: Greater driving dynamics, greater traction, greater safety

Don't Copy From This Blog...

The most innovative components of the new 4MATIC include the power take-off to the rear axle which is integrated in the 7G-DCT automated dual clutch transmission and the rear-axle gear with integrated, electrohydraulically controlled multi-disc clutch. This set-up enables fully variable distribution of the drive torque between front and rear axle. Additional benefits of this design are a lower system weight than is available from the competition and high efficiency.

The 4MATIC all-wheel drive is a completely new development tailored to the requirements of the new front-wheel drive architecture. The engineers at Mercedes-Benz have ventured into uncharted territory here, as the design of the previous model series ruled out the introduction of an all-wheel drive system based on a front-wheel drive architecture with transversely mounted front engines. On these previous models the differential was located in front of the engine in the direction of travel, thus thwarting any options of diverting drive power to the rear axle. In addition, the body design with sandwich floor prevented the integration of a cardan shaft to the rear axle.

For the new front-wheel drive vehicles, adequate installation space for an all-wheel drive powertrain was provided right from the initial stages of the planning process. In addition, the development engineers designed the powertrain such that the differential axle is situated behind the engine, thus enabling power to be branched off to the rear axle. The future all-wheel drive line-up from Mercedes-Benz will be heralded in the coming year by the new CLA and the particularly agile and powerful CLA 45 AMG. While the basic mechanical configuration is identical on all versions, the AMG models feature a modified power output to the rear axle.

Integrated power take-off unit (PTU) channels power to the rear axle

The new 4MATIC is being combined with the 7G-DCT seven-speed automated dual clutch transmission which was premiered in the B-Class. The power flux to the rear powertrain is provided by a compact power take-off unit (PTU) which is fully integrated in the main transmission and is supplied with lubricant from the latter's oil circuit. This configuration gives rise to substantial weight advantages in comparison to rival systems which branch off power by means of an add-on component with its own oil circuit. Together with the friction-minimised tapered roller bearings, the PTU achieves an excellent level of efficiency.

The low system weight of the new 4MATIC is not attributable solely to the PTU. Other weight-stripping measures include a compact rear-axle gear unit, inductively hardened rear-axle side shafts in hollow design and weight-optimised propeller shafts. The system weight of the new 4MATIC is up to 25 percent lighter than the all-wheel-drive versions offered by the competition. These lightweight design measures and the high functional efficiency result in a good level of energy efficiency.

As is always the case with all-wheel drive systems incorporating a transversely mounted drive unit at the front, the power flux requires to be diverted by 90 degrees. On the 4MATIC, this is achieved by quite simple means: the differential gearwheel of the main transmission drives the spur gear of the PTU and a compact bevel gear stage diverts the power flux. The rear axle is driven via an output flange and a cardan shaft.

A vibrationally decoupled intermediate bearing is fitted between the two-part cardan shaft and underbody and a flexible coupling is installed between the shaft and the rear-axle gear unit. An axially moving joint at the front compensates the typical movements of the engine-transmission unit under load and prevents the transfer of such movements to the rear powertrain. By virtue of these measures, all the 4MATIC versions attain a level of NVH comfort on a par with that of the comparable models with front-wheel drive. In order to minimise crash-induced stress for passengers in a head-on or rear-end collision, the cardan shaft is provided with a crash joint. Here again, the 4MATIC models attain a standard of safety on a par with that of the front-wheel drive models.

Completely new development with torque-on-demand rear axle

The electrohydraulically actuated multi-disc clutch integrated in the rear-axle gear unit is responsible for fully variable torque distribution. Operating principle: when the multi-disc clutch is open, the CLA is driven almost exclusively by the front axle. When the clutch is closed, the rear axle comes into play. This means that the drive torque can be shifted in fully variable mode between front and rear axle according to the given situation (torque on demand).
The system pressure to activate the rear axle is supplied in milliseconds by the rotor pump which is integrated in the rear-axle gear unit. The pump is activated automatically as soon as only minimal speed differences apply between front and rear axle. Pressure control is performed by a proportioning valve under the steering of the ESP®.

The most diverse parameters are taken into consideration here, such as lateral acceleration, steering angle, yaw rate, accelerator position, ABS control settings or the selected shift programme of the 7G-DCT dual clutch transmission. An additional pressure regulating valve limits the drive torque at the rear axle to 750 Newton metres. Up to 1000 Newton metres are possible on the AMG version.

Intelligent control systems for more enjoyable driving

The 4MATIC is activated according to the basic principle of "as often as necessary as rarely as possible". This means that when the underlying conditions allow the all-wheel drive CLA models run almost exclusively in front-wheel drive mode. As soon as the driving situation requires, additional drive torque is channelled to the rear axle as appropriate. The reverse process takes place just as quickly: as soon as additional drive torque is no longer expedient at the rear axle – e.g. in case of heavy braking manoeuvres with ABS intervention – the rear powertrain is deactivated and torque is reduced to zero. With this strategy, the developers have managed to combine two key requirements defined in the performance specifications: optimum energy efficiency coupled with maximum driving dynamics and driving safety.

In normal circumstances, the drive torque distribution between front and rear axle can be set from 100:0 to 50:50. In certain driving situations, such as when exceeding the µ-jump limit, higher levels of torque may be allocated to the rear axle to avoid unstable operating conditions. Here are some examples of torque distribution (front:rear in percent, approximate values):

- Full-load acceleration at approx. 50 km/h → 60:40

- Dynamic cornering under load → 50:50

- Exceeding the µ-jump limit → 10:90

- Heavy braking with ABS intervention → 100:00

Another basic principle of the 4MATIC system results in a further increase in driving dynamics, guaranteeing greater driving enjoyment without compromising driving safety. In case of understeering or oversteering under load, the drive torque is first of all distributed such as to stabilise the vehicle. This ensures that traction and driving enjoyment are fully maintained in speedy driving on winding stretches of road. Only if these measures fail to have a stabilising effect do the control systems adapted to 4MATIC conditions, such as ESP® or 4ETS, intervene to keep the CLA stable.

The 4ETS electronic traction system forms part of the ESP® electronic stability programme and brakes the driven wheels individually when they go into spin. This provides for a high level of traction on slippery surfaces, on roads which are icy on one side or in continually changing conditions. In a nutshell: while 4ETS is responsible for maintaining the highest possible traction in all conditions, ESP® serves as the higher-level control instance to ensure optimum driving stability.

Individual: driving modes to suit personal driving styles

As already mentioned, the torque distribution ratio is also dependent on the activated shift programme of the 7G-DCT dual clutch transmission. The ECO programme results in torque distribution of a conservative nature. Less torque is channelled to the rear axle, resulting in gentler handling and supporting an economical driving style at lower revs. In SPORT or MANUAL mode the activation times are shortened and more torque is distributed to the rear axle in the interests of a dynamic, sporty driving style.

On the AMG versions such as feature on the CLA 45 AMG, 4MATIC adaptation takes place in accordance with the 3-stage ESP® system, employing the user-selectable settings ESP ON, ESP SPORT Handling Mode and ESP OFF. This 3-stage stability programme is also applied to adapt the control strategies of the variable 4MATIC system. The new AMG 4MATIC applies more rear-biased torque distribution as a general principle, in order to increase lateral dynamics around the vehicle's vertical axis.

Detailed investigations in the testing phase

Alongside exact and realistic simulation using a digital prototype, extensive practical testing remains integral to the development phase of new models and drives. For the new 4MATIC, endurance testing and detailed tuning trials were carried out in all climatic zones and on all possible types of roads and surfaces. The test engineers carried out their work at test sites beyond the Arctic Circle and in desert regions, as well as trials closer to home at the Daimler test sites in Papenburg and Boxberg. Fine tuning of the control systems took place on race tracks such as the legendary Nürburgring Nordschleife and demanding alpine passes.

The test programme was backed up with extensive trials under standardised conditions on the all-wheel drive test rigs in Stuttgart-Untertürkheim. The entire powertrain with engine is set up on these large-scale test rigs and subjected to punishing treatment around the clock, following previously recorded and digitised test routes. Driving resistance is simulated here by four electric motors connected to the hubs of the respective wheels. This enables exact comparison of different design variants under standardised conditions without weather influences or changing road conditions, to reveal the best solution.

The test rig runs are also important for the purpose of tuning individual parameters. An example here is provided by the power take-off unit (PTU), which shares a common oil circuit with the main transmission in the interests of minimising component weight and maximising efficiency. As the lubricant supply process cannot be simulated exactly using a computer model, the engineers have come up with an "x-ray trick". They produce the housing in a robust, transparent material and install this "glass PTU" in the powertrain. HD cameras can then be used to provide a perfect view of the oil circuit during the subsequent runs on the test rig and optimisation measures can duly be carried out as necessary.

The above-described large-scale test rig demonstrates Daimler AG's commitment to maximum environment-friendliness and resource conservation with regard to the design and operation of test facilities. The four electric motors function as generators during braking, feeding the recuperated energy back into the power grid – at Mercedes-Benz, recuperation is not limited to the vehicles themselves.

Perfect duo: new 4MATIC and 7G-DCT dual clutch transmission

Drawing on over 50 years of experience in the development and production of automatic transmissions, Mercedes-Benz has ventured into new technical territory with the 7G-DCT dual clutch transmission: the new system is an automated three-shaft manual transmission consisting of two subtransmissions, each with its own clutch. Both actuation of the clutches and gear shifting take place fully automatically and without any interruption in tractive power. This enables a comfortable but nevertheless dynamic mode of driving. Thanks to its seven gears it offers a large gear ratio spread of up to 7.99. This means that a very short transmission ratio is available when moving off on an uphill slope with a high payload, for example, while during cruising the engine speed can be lowered considerably. The transmission's efficiency improves fuel economy by up to 9 percent in comparison to the CVT which has been employed in the A-Class to date, bringing fuel consumption down to a level below that obtained with a manual transmission.

At a length of 367 millimetres and a weight of 86 kilograms, the 7G-DCT is more compact and lighter than the transmissions in this torque class which have been available on the market to date. The clutches take the form of oil-cooled multi-disc clutches. The specially developed hydraulic fluid is actively cooled, thus ensuring correct functioning of the transmission even under extreme conditions, despite the comparatively low filling level of six litres. Excess engine heat can also be transferred to the transmission, which improves its efficiency.

For the first time on this type of unit, the transmission is supplied with oil by two oil pumps – one mechanical and one electric. The electric pump maintains the oil pressure when the engine is switched off via the start/stop function. This means that the transmission is immediately operational when the engine is restarted and the vehicle can move off again without any delay. In addition, the electric pump is able to support the mechanical pump when peak loads apply, enabling a more compact and efficient design for the mechanical pump.

Another new feature is electrical activation of the hydraulics for the parking lock, which is locked by mechanical means. This "park by wire" function enables the transmission selector lever to be positioned as desired: it is located in the form of a steering column lever on the right behind the steering wheel. In combination with the electric parking brake, additional space has thus been created in the centre console for additional stowage facilities.

Three gearshift programmes are available to the driver:

- ECONOMY: in this mode, the transmission performs gearshifts fully automatically and particularly comfortably. The gears are selected with due regard to a particularly economical style of driving at low revs

- SPORT: the transmission performs gearshifts fully automatically. The shift and response times are shorter, with gearshifts at higher engine speeds

- MANUAL: in this mode, the driver operates the transmission manually via shift paddles behind the steering wheel. The engine speeds at which the gears are shifted can therefore be freely chosen

In ECO or SPORT mode, the driver is still able to intervene manually in the gear-shifting process via the shift paddles. The transmission reverts to the selected automatic mode after the paddles have remained inactive for ten seconds, or after a longer delay when driving downhill or on winding roads.

Credits: Daimler AG

Copyright © 2012, mercedesgla. All rights reserved.

Read More

The summit of perfection with new 4MATIC: All-wheel drive for all – tailor-made solutions

Don't Copy From This Blog...

From next year, Mercedes-Benz will be offering a new generation of the 4MATIC permanent all-wheel drive system with fully variable torque distribution. This totally new development is based on the front-wheel drive architecture with transversely mounted engines. Like the other 4MATIC versions, it boasts high tractive power reserves and outstanding agility accompanied by optimum driving safety and energy efficiency. The new 4MATIC will complement the four all-wheel drive versions which have been available to date. This will ensure 4x4 technology tailored to the respective vehicle categories – from the new compact class and the models of the C-, E-, S-, CLS- and CL-Class to the comprehensive range of SUVs and ATVs covering the GLK-, M-, GL-Class and G-Class. The new 4MATIC will also boost driving enjoyment in the two particularly dynamic Mercedes-Benz CLA and CLA 45 AMG models. Both of these models will be premiered in 2013.

The most innovative components of the new 4MATIC include the power take-off to the rear axle which is integrated in the 7G-DCT automated dual clutch transmission and the rear-axle gear unit with integrated, electrohydraulically controlled multi-disc clutch. This set-up enables fully variable distribution of the drive torque between front and rear axle. Additional benefits of this design are a lower system weight than is available from the competition and high efficiency. Similarly to the front-wheel drive versions, all 4MATIC models also boast good energy efficiency.

The 4MATIC all-wheel drive is a completely new development tailored to the requirements of the new models with front-wheel drive. The future all-wheel drive line-up from Mercedes-Benz will be heralded in the coming year by the CLA-Class and the particularly agile and powerful CLA 45 AMG. While the technical basis is identical on all versions, the AMG models feature a modified power output to the rear axle.

Integrated power take-off unit (PTU) channels power to the rear axle

The new 4MATIC is being combined with the 7G-DCT seven-speed automated dual clutch transmission which was premiered in the B-Class. The power flux to the rear powertrain is provided by a compact power take-off unit (PTU) which is fully integrated in the main transmission and is supplied with lubricant from the latter's oil circuit. This configuration gives rise to substantial weight advantages in comparison to rival systems which branch off power by means of an add-on component with its own oil circuit. Together with the friction-minimised tapered roller bearings, the PTU achieves an excellent level of efficiency.

The low system weight of the new 4MATIC is not attributable solely to the PTU. Other weight-stripping measures include a compact rear-axle gear unit, inductively hardened rear-axle side shafts in hollow design and weight-optimised propeller shafts. The system weight of the new 4MATIC is up to 25 percent lighter than the all-wheel drive versions offered by the competition.
The two-part cardan shaft is vibrationally decoupled, with an axially moving joint at the front compensating the movements of the engine-transmission unit and preventing transfer to the rear powertrain. To minimise crash-induced stress, the cardan shaft is fitted with a crash joint.

Completely new development with torque-on-demand rear axle

The electrohydraulically actuated multi-disc clutch integrated in the rear axle gear unit is responsible for fully variable torque distribution. Operating principle: when the multi-disc clutch is open, the CLA is driven almost exclusively by the front axle. When the clutch is closed, the rear axle comes into play. This means that the drive torque can be shifted in fully variable mode between front and rear axle according to the given situation (torque on demand).

The system pressure to activate the rear axle is supplied in milliseconds by the rotor-type pump which is integrated in the rear-axle gear unit. The pump is activated automatically as soon as only minimal speed differences apply between front and rear axle. Pressure control is performed by a proportioning valve under the steering of the ESP®.

Intelligent control systems for more enjoyable driving

The 4MATIC is activated according to the basic principle of "as often as necessary, as rarely as possible". This means that when the underlying conditions allow, the all-wheel drive CLA models run almost exclusively in particularly economical front-wheel drive mode. As soon as the driving situation requires, drive torque is channelled to the rear axle as appropriate. The reverse process takes place just as quickly: as soon as additional drive torque is no longer necessary at the rear axle – e.g. in case of heavy braking manoeuvres with ABS intervention – the rear powertrain is deactivated and torque is reduced to zero.

In case of understeering or oversteering under load, the drive torque is first of all distributed such as to stabilise the vehicle. Only if these measures fail to have a stabilising effect do the control systems adapted to 4MATIC conditions, such as ESP® or 4ETS, intervene to keep the CLA stable. With this strategy, the developers have managed to combine two key requirements defined in the performance specifications: optimum energy efficiency coupled with maximum driving dynamics and driving safety.

Individual: driving modes to suit personal driving styles

The torque distribution ratio is also dependent on the activated shift programme of the 7G-DCT dual clutch transmission. The ECO programme results in torque distribution of a conservative nature. Less torque is channelled to the rear axle, resulting in gentler handling and supporting an economical driving style at lower revs. In SPORT or MANUAL mode the activation times are shortened and more torque is distributed to the rear axle in the interests of a dynamic, sporty driving style. On the AMG versions, adaptation of the 4MATIC controller takes place in accordance with the 3-stage ESP®.

New 4MATIC featuring in the Mercedes-Benz CLA

The future all-wheel-drive line-up from Mercedes-Benz will be heralded in the coming year by the CLA-Class and the particularly agile and powerful CLA 45 AMG. The new Mercedes-Benz CLA adopts the avant-garde design of the Concept Style Coupé into series production almost 1:1. In keeping with its sporty positioning, the CLA is available with high-torque turbo engines rated at up to 155 kW (211 hp), sports suspension and the newly developed 4MATIC. The technical highlights include numerous driving assistance systems, such as advanced COLLISION PREVENTION ASSIST.

CLA 45 AMG: the most dynamic way to experience the new 4MATIC

As the high-powered top model of the new compact class, the CLA 45 AMG broadens the portfolio of Mercedes-Benz's high-performance brand to offer a fascinating high-performance vehicle in this class, too. The newly developed AMG 2.0-litre four-cylinder turbo petrol engine will set new standards in its engine capacity segment: with maximum torque of well over 400 Newton metres and low fuel consumption, AMG is aiming to lead the competition. In conjunction with the specially adapted 4MATIC version for this engine-power class, the CLA 45 AMG will be one of the most dynamic, powerful and efficient four-cylinder series-production compact cars.

Elegant in all weathers: the CLS Shooting Brake 4MATIC

The CLS Shooting Brake sees Mercedes-Benz making its mark once again with a creative design concept that underscores its leading role in the design field. Surprising yet unequivocally coupé, the CLS Shooting Brake's proportions create a crouched posture, as if the vehicle were poised to make a leap: long bonnet, narrow window profile with frameless side windows, roof sloping dynamically towards the rear and continuing to the tail end of the vehicle. Only at second glance does it become clear that the Shooting Brake actually has five doors and offers more in terms of functionality. In essence it represents an unprecedented version of a sports car with five seats and a large tailgate.

Like all 4MATIC models from Mercedes-Benz, the high-powered and high-torque CLS 350 CDI 4MATIC (195 kW/265 hp, 620 Nm) and CLS 500 4MATIC (300 kW/408 hp, 600 Nm) feature a permanent all-wheel drive system which guarantees optimum traction and the best possible agility and safety – particularly in wintry road conditions.

New GL- and GLK-Class all set for their first winter

The new GL-Class which is available from November 2012 is the pinnacle of perfection in the ATV and SUV world. It offers a luxurious interior with seven full-size seats and superlative ride comfort accompanied by highly dynamic performance on dry, wet or wintry roads. The premium SUV also boasts outstanding off-road capabilities, thanks to new suspension developments and innovative dynamic handling control systems which enhance both driving pleasure and safety on the road. In a nutshell, the GL-Class is a seven-seater, all-terrain S-Class.

The optional ON&OFFROAD package for the GL-Class uses six different driving modes to optimise driving dynamics and handling safety by providing the optimum drive control needed to cope with the wide spectrum of operating conditions encountered both on and off road. Drivers have the choice of an automatic mode, two specially programmed off-road modes as well as three on-road modes – "Winter", "Sport" and "Towing". The winter driving mode of the ON&OFFROAD package improves handling on glazed frost, snow and ice or when using snow chains and offers additional safety.

When the ON&OFFROAD package is combined with another optional feature, the ACTIVE CURVE SYSTEM, a specially programmed winter set-up offers dynamic driving pleasure while giving the driver excellent control over the vehicle for a high degree of handling safety. At the same time, the system is capable of giving the GL-Class greater traction, especially in wintry road conditions with low grip levels. What’s more, this set-up boasts even greater directional stability in tighter corners thanks to a special control algorithm that is programmed into the system.

April witnessed the premiere of the second new SUV to be launched in 2012: the revamped GLK-Class from Mercedes-Benz. This SUV is now able to demonstrate its outstanding capabilities in wintry conditions, too. Its claim to leadership of the compact SUV segment is underscored by trailblazing assistance systems, engines matching efficiency with agility, a new design and an extended range of equipment and appointments.

The 4MATIC on the GLK is based on the version featuring on the C-, E-, CLS- and S-Class, whereby its outstanding off-road capability sets it apart from the saloons and coupés, however. For keen off-road enthusiasts, an Offroad Engineering package is additionally available to further broaden the scope for off-road adventures. At the touch of a button a special drive programme is started which varies the shift points of the 7G-TRONIC, "softens" the accelerator characteristics and activates the ESP® off-road functions with off-road ABS and a special off-road 4ETS system. An additional switch activates Downhill Speed Regulation (DSR).

Even the best all-wheel drive is no substitute for winter tyres

Like any other all-wheel drive system, the 4MATIC versions have to abide by the laws of driving physics. The fundamental rule is that a tyre is only able to transfer a certain level of overall force to the road surface. If a particularly high degree of longitudinal force is required during acceleration or braking, for example, the available lateral force is reduced. When cornering, the reverse applies: now a large amount of lateral force is required to keep the vehicle on course, while the longitudinal force potential is restricted. The engineers' skill in designing the drive mechanism and fine-tuning the control systems lies in their ability to exploit these correlations in such a way as to ensure the best possible handling characteristics under all conditions. The frictional coefficient µ describes the physical grip between the tyres and the ground. This figure is high on a dry road (µ = 0.9) and low on a snow-covered road (µ = 0.3).

Despite all the engineers' efforts, it is ultimately the drivers themselves who determine how safe they are out on the road. They should always adapt their driving style in accordance with the prevailing wintry conditions and ensure that their vehicle is suitably equipped; winter tyres are absolutely essential here.

The full works: the 4MATIC range from Mercedes-Benz

In addition to the described models, the 4MATIC range also extends to the saloon and estate versions of the E- and C-Class, the luxurious S-Class, the CL luxury coupé, the four-door CLS Coupé and the R-Class. The M-Class and the legendary G-Class round off the range in the SUV and ATV segment. The all-wheel drive line-up from Mercedes-Benz also includes an exotic model in the guise of the SLS AMG Electric Drive. Four electric motors on this vehicle guarantee tremendous thrust, with fully variable and selective drive torque distribution to the individual wheels. In all, the 4MATIC range currently comprises 51 models. And when the compact models featuring the new 4MATIC generation round off the range next year, it will really be a case of all-wheel drive all-round! The 4x4 family from Mercedes-Benz will then cover almost 60 models.

Credits: Daimler AG

Copyright © 2012, mercedesgla. All rights reserved.

Read More

From the Dernburg-Wagen to the A 45 AMG: 105 years on, the original four-wheel drive inspires a new generation

Don't Copy From This Blog...

This year marks the 105th anniversary of the very first commercially available four wheel drive vehicle – created in 1907 by Daimler-Motoren-Gesellschaft (DMG). The ‘Dernburg-Wagen’ featured not only four-wheel drive but was also equipped with four-wheel steering to aid manoeuvrability.

With ground clearance of 32-centimetres and powered by a substantial 6.8-litre, four-cylinder engine developing a modest 35 hp at 800 rpm it was capable of carrying five passengers. Solid steel wheels wrapped in pneumatic tyres helped protect the drum brakes from debris.

Today Mercedes-Benz UK offers a total of four road car variants including the recently launched GL-Class, two van lines as well as the Canter and Zetros and the mighty Unimog, all equipped with sophisticated four-wheel drive systems.

The applications of four-wheel drive have come a long way since 1907. In 1947 the ‘Universalmotorgerat’ (Universal Motor Vehicle) or Unimog was unveiled in Germany. Then, as it is to this day, the Unimog was fitted with four wheels of equal size, four-wheel drive with front and rear differential locks and axles optimised for off-road use. While the engines and four-wheel drive systems are now more advanced, the original virtues of immense strength, durability and go-anywhere ability remain.

In 1972 development of what would become the G-Class began with production following in 1979. Contrary to popular belief, it was not designed for military purposes – instead it was aimed as a robust commercial vehicle with incredible off-road ability. With a climbing ability of up to 80 per cent, a tilt angle of up to 54 per cent and 21-centimetre ground clearance, the G-Class lived up to its design objectives. As with the Unimog, the G-Class remains faithful to its original formula some 33 years on – today it’s fitted with permanent all-wheel drive, fully engageable differential locks, four-wheel Electronic Traction System (4ETS) and a low-range gear reduction.

Mercedes-Benz has since broadened and refined the range of vehicles it offers with four-wheel drive. From the 4MATIC passenger cars first introduced in 1985 to the M-Class which started production in 1997 at the Tuscaloosa production facility in Alabama. By 2009 the millionth M-Class had been produced – with a further 500,000 vehicles being added to that total today, including the R-Class and GL-Class built at the same location.

Both the M-Class and GL-Class are available with locking differentials to ensure they remain highly adept in off-road conditions.

Commercial vehicles also benefit from four-wheel drive, with examples of the Vario and Sprinter capable of being specified with the system as well as the Canter and Zetros

This commitment to four-wheel drive systems will be sustained in the future by the announcement that the new A 45 AMG will be fitted with a specially developed all-wheel drive system to ensure maximum traction regardless of road conditions.

Credits: Mercedes-Benz UK

Copyright © 2012, mercedesgla. All rights reserved.

Read More