The technology of the new 4MATIC system
Latest generation of trend-setting all-wheel-drive system
• Power split between front and rear wheels in ratio of 45 to 55 percent
• Multiplate clutch with 50 Nm locking force offers additional traction
• Handling is clearly defined and always predictable
• Compact, lightweight design is optimised for reduced friction losses
The Mercedes-Benz S-Class traditionally embodies the state of the art with regard to technical innovations – indeed, these have always made this top-of-the-range Mercedes the model for all passenger-car development.
The same holds true for the new 4MATIC models, which are equipped with a trend-setting all-wheel-drive system of the latest generation.
During the concept, design and development stages of this new drive technology, the principal objectives were:
• Top traction performance on all road surfaces.
• Retention of the outstanding handling characteristics and first-class ride comfort.
• Performance and fuel consumption figures which are almost as good as those of two-wheel-drive vehicles.
• Compact and weight-optimised design.
• Attainment of the highest possible passive-safety standards.
In order to achieve these ambitious goals, the engineers and technicians of the Mercedes Technology Center (MTC) in Sindelfingen and Stuttgart-Untertürkheim decided to undertake a complete redesign of the all-wheel-drive system.
The permanent 4MATIC all-wheel-drive system in the S-Class has a planetary-type central differential which splits the power between the front and rear wheels in a fixed ratio of 45 to 55 percent.
The permanent all-wheel-drive system is active all the time, operates without the need for electronically controlled clutches and does not require any reaction time.
As a result, the S-Class 4MATIC offers assured, clearly defined handling which is always predictable on all road surfaces – a clear advantage over other systems.
On snow and ice in particular, the adhesion of all four wheels is maximised by a multiplate clutch whose locking force of 50 Nm ensures optimum traction.
Complementing the high-precision mechanical components, the 4ETS and ASR electronic traction systems interact intelligently with the ESP® active safety system.
The new 4MATIC all-wheel-drive system is designed in such a way that other Mercedes-Benz passenger cars will be able to benefit from it in the future.
Space-saving design with integrated transfer case The power supply to the driven front wheels is provided via a transfer case which requires no additional installation space as it is integrated in the 7G-TRONIC automatic transmission.
From here, a driveshaft supplies the power to the front axle. From the front differential, power is transmitted to the front left axle shaft by an intermediate shaft which runs through an encapsulated shaft channel in the engine oil sump.
The transfer case is notable for its compact design: by dispensing with one complete gear stage and by integrating the rear universal joint in the output gear, it is possible for the drive shaft to the front differential to run very close to the automatic transmission.
Together, all these design measures allow identical floor assemblies to be used as for vehicles with rear-wheel drive. As a consequence, customers who choose the new S-Class 4MATIC no longer have to compromise on space.
Packaging the all-wheel-drive technology in this way also has the advantage that the results of all the relevant crash tests are almost identical to those obtained with rear-wheel-drive vehicles.
Noise and vibration comfort to typically high S-Class standards Another benefit of this compact drive concept relates to the fact that the engine mounts are positioned on the new integral subframe and thus permit the use of extremely compact and rigid engine supports.
This has a positive effect on noise and vibration comfort; on both counts, the 4MATIC models match the acknowledged high standard of the rear-wheel-drive S-Class.
A no less important factor in this context is the high natural bending frequency of the entire enginetransmission unit, including the favourable integrated transfer case.
The noiseoptimised design of the oil supply system and all rotating components also plays an important part in this.
Additional all-wheel-drive-related fuel consumption just 0.4 litres The inter-wheel speed difference is absorbed by means of a rear differential whose design (it is linked to the engine by a shortened propshaft) offers particular benefits with regard to fuel economy.
The principle of the friction-optimised design of the rear differential has also been adopted for the newly developed front differential which has a diecast aluminium housing: by integrating the transfer case in the 7G-TRONIC automatic transmission it has been possible to dispense Compact and light: The new 4MATIC all-wheel-drive system for the S-Class was developed by Mercedes-Benz in-house.
entirely with one gear stage and the associated seals. Optimum lubrication efficiency is achieved by sharing the oil circuit with the automatic transmission; lowfriction bearings are also used.
Together, these measures allow the S-Class 4MATIC models to return additional (NEDC combined) fuel consumption of just 0.4 litres per 100 kilometres – a figure so low as to be unrivalled – compared with the rear-wheel-drive models.
Furthermore, the compact and weight-optimised design results in an all-wheel-drive weight premium of just 66 to 70 kilograms, depending on the engine – a clear advantage over all the competitor models.
The low additional weight makes modified gear spacing and final drive ratios superfluous – another factor which has a positive effect on fuel consumption and performance figures.
Multiplate clutch offers additional traction In addition to the permanent all-wheel-drive system, an innovative multiplate clutch also helps ensure high traction in all road conditions.
It is fitted to the central differential and produces a basic locking force of 50 Newton metres between the front and rear axles.
If extremely low friction values – as encountered on ice, for example – are preventing one of the axles from transmitting any drive torque, the multiplate clutch helps by transferring the engine power from the axle which is turning faster to the one which is turning more slowly without any time-lag whatsoever.
As a result, the wheels without traction are prevented from spinning. As well as enhancing traction, this system improves stability, too.
ESP®, ASR und 4ETS active safety systems completely redeveloped
This highly effective technology is complemented by the ESP®, ASR and 4ETS electronic active safety systems which have been completely redeveloped to take account of the specifics of all-wheel drive.
The 4ETS traction control system uses a whole series of sensor data about the speeds of the different wheels, the steering angle as well as the vehicle’s rotational motion and transverse acceleration.
A micro-computer uses this data as a basis for correctly adjusting the automatic braking impulses in accordance with the driving situation.
This improves traction when starting out from a standstill on a slippery surface and provides greater stability during challenging driving manoeuvres.
4ETS replaces conventional mechanical differential locks and is able to brake one or more wheels at the first sign of a loss of traction, thereby instantly increasing the drive torque to the wheels with best traction.
4ETS and ASR intervene almost imperceptibly as far as the vehicle occupants are concerned and combine optimum traction with maximum driving stability and excellent handling.
At low speeds, 4ETS brakes up to three wheels, which provides the same effect as three differential locks and ensures maximum traction.
At higher speeds, the system reduces the automatic braking impulses to ensure stability. As well as making the S-Class 4MATIC models extremely safe cars, this combination of ESP® and 4ETS Increased traction: The multiplate clutch improves take-off on slippery surfaces.
As with ESP® in model variants with rear-wheel drive, the all-wheel-drive vehicles also immediately warn drivers when they approach their physical limits. In this case, a yellow warning light in the instrument cluster begins to flash.
This is a clear signal warning drivers to adjust their driving behaviour to the road conditions.
Four-link front suspension and multi-link independent rear suspension for optimum comfort and handling Another key element which underpins the excellent driving dynamics and high ride comfort typical of the brand is the suspension design of the S-Class.
Unlike the predecessor model series, the all-wheel-drive versions now feature the fourlink front suspension which offers the best compromise between agility, precision and ride comfort.
Equipped with the tried and trusted multi-link independent rear suspension, the 4MATIC Saloons are characterised by handling that is always predictable and neutral with slight understeer.
At the same time, the powerassisted rack-and-pinion steering makes for precise and effortless vehicle control.
Thanks to its variable ratio (50.1 to 60.5 millimetres per steering wheel revolution), it works somewhat more indirectly in the middle of the range than at the extremes.
Comfort is considerably enhanced by the speed-sensitive feature that comes as standard: the lower the speed, the greater the power assistance.
Below 200 km/h, the required steering input diminishes continuously as a function of the driving speed, so that the driver need apply only about a third of the maximum steering effort during slow parking manoeuvres.
Variable centring is a special feature common to all S-Class models: the electro-hydraulic speed-sensitive servo is used to generate a centring moment that increases with the speed and gives the driver a secure and stable feeling in the straight-ahead position.
In slow driving, this additional steering moment is not activated, so the benefits of the speed-sensitive steering can be fully exploited.
Standard: AIRMATIC all-round self-levelling air suspension
The standard-fit AIRMATIC all-round self-levelling suspension makes an important contribution to the high standard of ride comfort offered by the S-Class 4MATIC versions.
When the vehicles are stationary, there is no difference between the ground clearance and ride height of the all-wheel-drive and rear-wheel drive models.
On rough roads, where greater ground clearance is required, the S-Class driver can simply press a button to raise ride height by 30 millimetres.
AIRMATIC is combined with the Adaptive Damping System (ADS). ADS constantly regulates the shock absorber force in line with requirements, taking the road conditions, the driving style and the car’s load into account.
The system is able to adjust the damping force at each wheel to the requirements of the prevailing situation within just 50 milliseconds.
In doing so, the skyhook algorithm regulates the damping forces in such a way that the forces exerted on the car body by the movement of the wheels are reduced.
Depending on the commands received, the ADS solenoid valves on the shock absorbers can actuate any of four different damper settings:
• Stage 1: Comfortable ride with little body movement and low acceleration values, due to soft compression and rebound.
• Stage 2: Skyhook mode – soft rebound setting and hard compression.
• Stage 3: Skyhook mode – soft compression setting and hard rebound.
• Stage 4: Hard compression and rebound setting to reduce wheel load fluctuations during dynamic driving.
Typical of Mercedes: The four-link front axle combines maximum flexibility, precision and ride comfort.
When experiencing few body movements, the new S Class remains in the comfortable ADS Stage 1. If the speed of body movements exceeds a certain value, the system shifts to the skyhook algorithm and continuously switches between the
second and third damping stages, with the help of fast solenoid valves, in order to offset body roll and pitching.
Another special feature is the S/C/M button in the centre console. The motorist can use this button to switch the saloon’s characteristics from “comfortable” to “sporty”, thereby influencing the suspension settings, ride height and transmission programming.
On 4MATIC models, the shift points for all gears are optimally adapted to all-wheel drive.
• Comfort: In this mode, the ride height of the 4MATIC saloons is raised by ten millimetres over that of the rear-wheel drive versions, provided the speed remains below 80 km/h. When the speed exceeds 80 km/h, AIRMATIC automatically lowers the ride height by ten millimetres at both axles in order to improve stability and reduce drag. At more than 160 km/h, the body is lowered by a further ten millimetres and the compression damping is changed to “hard”. When the speed drops below 40 km/h again, the system returns the body to its normal height. The automatic transmission shifts gears at lower engine speeds and allows the S Class to move off in second gear.
• Sport: In this mode, the ride height is the same when on the move as for rearwheel drive S-Class models. At speeds exceeding 100 km/h, ride height is lowered by ten millimetres at both axles and is not raised again until the speed drops below 60 km/h. The shock absorbers are set to the “hard” compression setting from 40 km/h. Gear changes take place at higher rpm.
• Manual: The automatic transmission can be operated manually by means of buttons on the steering wheel. The alterations to ride height and suspension settings take place in the same way as in “Sport” mode
Newly developed 4MATIC all-wheel drive for the S-Class
Comfort and driving dynamics attain a new level of perfection
Stuttgart – The Mercedes-Benz S-Class is now available with 4MATIC permanent all-wheel drive.
Developed entirely in-house by Mercedes-Benz, this all-new drive system combines perfect traction, first-class comfort and impressive driving dynamics with good fuel economy.
Two powerful eight-cylinder models are available in the form of the S 500 4MATIC and S 450 4MATIC while the S 320 CDI 4MATIC is the first S-Class all-wheel-drive variant to be equipped with a particularly economical V6 diesel engine.
The new models with all-wheel drive are identified clearly by the 4MATIC legend which appears both on the boot lid and on the wooden trim element on the centre console.
The top model from Mercedes-Benz with the new 4MATIC all-wheel-drive is aimed at drivers whose principal requirement is for a luxury saloon able to cope with all weather conditions with absolute assurance.
This need is met by the S-Class 4MATIC models, whose newly developed drive system features a planetary-type centre differential.
The permanent, fixed power split between the front and rear wheels in a ratio of 45 to 55 percent guarantees assured and absolutely predictable handling on all road surfaces.
An integrated multiplate clutch ensures additional traction and optimum directional stability as soon as the wheels show any sign of slipping.
With the support of the ESP®, ASR and 4ETS electronic driving safety systems, the S-Class 4MATIC offers a dynamic, comfortable and safe transport solution, even in adverse road conditions.
Trend-setting all-wheel-drive system developed by Mercedes-Benz
The 4MATIC system’s compact, light and friction-optimised design offers clear advantages over other systems with regard to weight, fuel consumption, comfort and passive safety.
Depending on the engine type, the all-wheel-drive technology results in an unrivalled low additional weight of just 66 or 70 kilograms.
Mercedes-Benz will also be offering this trend-setting all-wheel-drive technology in other passenger cars in the future.
The new 4MATIC drive for the S-Class was developed independently by a team of specialists at the Mercedes Technology Center in Sindelfingen and in Stuttgart-Untertürkheim.
The all-wheel-drive components are produced in a coordinated production system comprising the Stuttgart-Untertürkheim, Esslingen-Hedelfingen and Esslingen-Mettingen major component plants.
Two powerful eight-cylinder models with 4MATIC
Assured performance of the highest order is guaranteed by the S 500 4MATIC und S 450 4MATIC eight-cylinder models.
In the S 500 4MATIC, the advanced 5.5-litre V8-engine with four valves per cylinder, 285 kW/388 hp and 530 Newton metres offers first-class performance: the new S 500 4MATIC accelerates from 0 to 100 km/h in 5.4 seconds and is therefore as fast as the rear-wheel-drive variant.
Thanks to the optimised weight and friction characteristics of the all-wheel-drive system, the additional fuel consumption is agreeably low.
With figures of 12.1 to 12.3 litres per 100 kilometres (NEDC combined) compared with 11.7 to 11.9 litres per 100 km for the S 500 without all-wheel-drive, it is clear that the new drive system is able to offer impressive savings.
The S 450 4MATIC is powered by a 4663-cc, eight-cylinder engine with four valves per cylinder which develops, 250 kW/340 hp and 460 Newton metres of torque.
Here, too, this V8 model with all-wheel-drive accelerates as quickly as its rear-wheel-drive counterpart, attaining 100 km/h in 5.9 seconds. With NEDC combined fuel consumption of 11.6 to 11.8 litres per 100 kilometres, the additional fuel consumption – as in the case of the S 500 4MATIC – is only 0.4 litres.
A first for the S-Class: all-wheel drive in combination with a diesel engine
An even more economical choice is available in the form of the new S 320 CDI 4MATIC – a model which marks a first for the S-Class by combining all-wheel drive with a diesel engine.
The advanced V6 turbodiesel with common rail high-pressure injection develops 173 kW/235 hp and 540 Newton metres of torque, accelerating the saloon to 100 km/h in 7.8 seconds; the top speed is 245 km/h.
With fuel consumption of between 8.7 and 8.9 litres of diesel per 100 kilometres, this model has a range of more than 1000 kilometres.
Like the V8 petrol models, the S 320 CDI 4MATIC consumes just 0.4 litres more fuel than the equivalent model with a standard drive system.
On all S-Class 4MATIC models, power management is performed by the 7G-TRONIC automatic transmission with steering-column DIRECT SELECT gear selector and steering-wheel gearshift buttons.
The V6 and V8 petrol-engined models are equipped as standard with the 7G-TRONIC Sport transmission, which is tuned for more direct, faster response.
Immediate market launch for V8 models, V6 CDI follows in December 2006
The S 500 4MATIC, S 450 4MATIC and S 320 CDI 4MATIC are available in short and long wheelbase versions. The market launch of the V8 models in Mercedes-Benz sales and service outlets and authorised dealerships will start in September 2006.
The diesel variant will appear in December 2006, to be followed by the S 350 4MATIC with a 200-kW/272-hp V6 petrol engine in mid-2007.
|Nm from rpm
|Top speed km/h
|S 320 CDI
Wide variety: 48 all-wheel-drive models from Mercedes-Benz
The extended choice of all-wheel-drive vehicles from Mercedes-Benz now comprises seven model series and impresses with its great diversity: it starts with the C and E-Class, both of which are available with 4MATIC in Saloon and Estate form, and includes the new S-Class and the R-Class touring SUV, both of which are available in two body variants.
Furthermore, the Stuttgart-based auto maker produces three off-roaders – the new GL-Class, the M-Class and the G-Class, a classic among cross-country vehicles. In total, therefore, Mercedes-Benz offers no less than 48 all-wheel-drive models.
This product initiative reflects the considerable emphasis which Mercedes-Benz is placing on the market for all-wheel-drive passenger cars and off-roaders – a market characterised by a distinct year-on-year growth trend.
A look at the S-Class segment also makes this clear: in the German market, the share of all-wheel-drive models increased from six percent in 2002 to nine percent in 2005.
During the same period, the all-wheel-drive share of this segment in the European market also increased from six percent to nine.
Worldwide sales of the S-Class 4MATIC predecessor model, which was launched in 2002, amounted to almost 29,000
vehicles in just under three years.
In 2005, the all-wheel-drive S-Class models had a worldwide share of about 18 percent of the total sales volume of this model series.
Overall, Mercedes-Benz has sold more than 1.2 million passenger cars and cross-country vehicles with permanent all-wheel-drive (figures correct as of July 2006).
Over 20 years of 4MATIC from Mercedes-Benz
The 4MATIC all-wheel-drive system made its world debut at the Frankfurt Motor Show in 1985. One year later, Mercedes-Benz presented the new technology in the E-Class of the time, the 124 model series.
Delivery of the first models with the automatically engaging all-wheel-drive system began in spring 1987. The successor model series, the 210, premiered a completely new permanent all-wheel drive system in 1997.
As the first all-wheel-drive passenger car from the Stuttgart-based car brand, the E-Class paved the way for the adoption of this innovative drive and safety technology in other Mercedes-Benz model series.
4-Matic is the name of an AWD four-wheel drive system developed and used by Mercedes-Benz. It is good for driving through slippery terrain.
Mercedes-Benz 4MATIC: the pinnacle of permanent all-wheel drive
The great 4×4 for the winter
Stuttgart/Hochgurgl – All-wheel drive is still the top choice for enhanced mobility when road conditions turn wintry.
4MATIC, the permanent, electronically controlled 4×4 system from Mercedes-Benz, promises particularly impressive progress, as it boasts truly formidable performance capabilities on snow-covered and icy roads.
High traction reserves, excellent directional stability, peerless safety and exceptional comfort levels are all among the drive concept’s highly persuasive benefits.
Not all 4MATIC systems are the same, though – Mercedes-Benz tailors the system to suit the operating profile.
So, the new M-Class is equipped with a 4MATIC variant that delivers supremely assured handling on the road combined with top-class off-road technology, while the E-Class employs a system which is geared towards optimum on-road performance.
One basic rule applies to all 4MATIC models in the winter, namely that the system can only work as effectively as the connection between the vehicle and the ground allows.
In other words, suitable winter tyres are still indispensable.
Outstanding safety and well-balanced ride comfort combined with impressive driving dynamics on dry, wet or wintry roads are some of the key strengths of the third-generation M-Class with permanent all-wheel drive.
The premium SUV also makes its mark with superlative skills off the beaten track, thanks to new chassis developments and innovative dynamic handling control systems designed to increase both driving pleasure and active safety.
The optional ON&OFFROAD package for the new M-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 the 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 ON&OFFROAD package’s winter driving mode improves handling characteristics on roads affected by snow, ice or freezing rain and when using snow chains, and offers added safety.
The extensive fine-tuning work carried out focused on further increasing longitudinal traction, at the same time as improving lateral dynamics and handling safety.
The development team was able to implement these specifications to impressive effect using special control mechanisms in the drivetrain.
When the ON&OFFROAD package is combined with another optional feature, the ACTIVE CURVE SYSTEM (ACS), 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 M-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 produced by a special control algorithm that is programmed into the system.
E-Class 4MATIC: stable handling on snow and ice
As with the system’s set-up on a dry or wet road, handling stability and, therefore, active safety are paramount at all times when wintry conditions prevail too in the E-Class models with 4MATIC.
The mechanical principle of the 4MATIC system, featuring a 45:55 torque split between the front and rear axles and a multi-disc limited-slip centre differential with a basic locking torque of 50 Nm, offers all the right ingredients for this.
This basic design enables high levels of traction, as the dynamic shift in axle load toward the rear axle that occurs during acceleration is harnessed to deliver more drive torque to the rear wheels.
However, the multi-disc differential lock is also able to shift the drive torque between the front and rear axles, varying the split between 30:70 and 70:30 as the road conditions dictate.
Consequently, intervention by the ESP®, 4ETS or ASR electronic control systems can be delayed for as long as possible and the bulk of the drive torque converted into tractive power, even on slippery roads.
All control system interventions go virtually unnoticed, yet drivers still know straight away if they are driving near the limit, as a yellow warning symbol will flash in the instrument cluster.
This serves as a clear prompt to adapt the driving style to the road conditions.
For the first time ever, an E-Class with 4MATIC and a four-cylinder diesel engine is being made available in the shape of the E 250 CDI 4MATIC BlueEFFICIENCY.
This model has an output of 150 kW (204 hp) and stands out for its smooth drive coupled with remarkable performance.
In the process, it burns just 5.6 l/100 km on the NEDC cycle, making it the most efficient all-wheel drive diesel car in its class.
Mercedes offers 4MATIC in 49 passenger car models
The Mercedes-Benz all-wheel drive line-up currently encompasses 49 passenger car models across ten model series for the German market, and offers an impressively wide choice.
Besides the E-Class and the C-Class, which both come in saloon and estate variants, the 4MATIC portfolio is enriched by models from the S-Class, CL luxury coupé, CLS four-door coupé and R-Class touring SUV‑ranges too.
These are joined by the third-generation M-Class that was brought out this year, the compact GLK and the GL full-size SUV.
Still going strong after over 30 years in production, the G-Class truly comes into its own off the beaten track and continues to rank as one of the best cross-country vehicles in the world.
Almost all their vehicles featuring this system also have an automatic transmission in standard equipment (except 260 and 300 gasoline and aspirated 300D were standard with manual transmission) and that’s where its name is derived from (4-wheel drive and automatic).
The first design of 4Matic (or 4-Matic) system was introduced in 1986 on the W124 series (E Class) saloons (four door) and estate (station wagon) cars.
It was available with the 2.6 L and 3.0 L 6 cylinder petrol (gasoline) and diesel engines.
Some newer versions of 4Matic are true AWD as the system remains active at all times, allowing these 4Matic-equipped automobiles to employ the system while driving on pavement, unlike prior models where the system was simply for navigation of slippery terrain, and in order to prevent damage to the vehicle shouldn’t be used on pavement.
A complex electronically controlled system with automatically engaging four-wheel drive (4WD), the system employs locking central and rear differentials to provide additional traction in slippery conditions.
The centre differential, also known as the transfer case, contains two clutches.
Each hydraulically enabled clutch is controlled separately to allow for three modes of operation; 2WD (mode 0) where 100% of available torque is available to the rear axle, while the front axle is disconnected and two 4WD modes which allow for 35% front/65% rear axle torque split (mode 1) or 50% front/50% rear axle torque split (mode 2).
The rear differential lock, previously known as ASD on Mercedes-Benz models, can also be locked (mode 3) if rear wheel slip is still present the transfer case 50/50 4WD mode 2 is engaged.
Due to safety and stability concerns there is no front differential lock. The 4Matic system uses inputs from the three channel ABS system and a steering wheel angle sensor to decide when to intervene.
4WD is disengaged automatically if the ABS service brakes are applied. Engine throttle control is not inherent in the W124 system.
Two W124 variants of the 4Matic system were produced, the first system (1986-1991) used a mechanical pressure test lever to disable the system hydraulically while the second system variant (1992/1993) used an electrical test switch to break power to the system.
The latter system variant when in test mode allows for continued operation of the rear shock self-levelling-system (SLS) when installed.
Plagued with reliability problems at first, the multiplate clutch central differential were prone to failure (Ritter, S: Mercedes-Benz E class Owners Bible Problems Section page 314 Bentley Publishers 2007) ; it was withdrawn in 1993.
The four wheel drive system was developed in conjunction with Steyr-Daimler-Puch, who manufactured the Mercedes-Benz G-Class in Austria.
The second generation of 4Matic was re-introduced on the W210 series in 1998/1999.
Available only in left hand drive the cars were again manufactured at the Magna-Steyr plant in Austria. The second generation of 4Matic used a full time 4 wheel drive system with three open differentials front, centre and rear.
Traction control is achieved using ETS (Electronic Traction System). This employs the ABS system with additional valves to monitor and then partially brake any wheel which loses traction.
This much simpler system is also used in the Mercedes-Benz M-Class SUV.
The second and third generation 4Matic systems are currently available on the E-Class, C-Class, R-Class, S-Class, Viano and the entire Mercedes-Benz SUV range.
These latter systems include engine and automatic stability controls.
The summit of perfection with new 4MATIC
All-wheel drive for all – tailor-made solutions
Stuttgart/Hochgurgl. 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 4×4 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
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 4×4 family from Mercedes-Benz will then cover almost 60 models.
4MATIC for the compact model range from Mercedes-Benz
Greater driving dynamics, greater traction, greater safety
- Fully variable permanent all-wheel drive for the front-wheel vehicles
- Dual clutch transmission with integrated power take-off
- Torque on demand-rear axle
- Intelligent control systems for safer and more enjoyable driving
- Different modes to suit personal driving styles
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.
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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.
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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®.
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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.
Click image to go to Mercedes miniwebsite about 4-Matic.
Or this one, produced by Mercedes UK