Nothing beats experience – except even more experience. With every new model, Mercedes-Benz increases its more than 60 years of expertise in the field of passenger car safety, translates the latest accident research findings into specific protective measures and develops pioneering, new driver support systems to make driving even safer.
Mercedes-Benz has also brought the C-Class - and therefore automobile engineering as a whole in this market segment – a considerable step further where safety is concerned. Once again the specialists in Sindelfingen have learned more from their own accident research, once more their thorough testing has helped to improve occupant protection further with intelligent details, and once again they have ensured that even more drivers benefit from the cutting-edge technology of the luxury class.

The Mercedes philosophy PRO-SAFE™ is the driving force and ideal for this commitment. It defines safety as a comprehensive undertaking that goes well beyond compliance with standardised crash test regulations. It concerns itself with all aspects of driving – everything that is important for the safety of the vehicle occupants and other road users. The Mercedes safety concept divides these aspects into four phases:

1. Safe driving:
Avoiding danger, warning and assisting in good time

2. When danger threatens:
Acting preventively with PRE-SAFE®

3. During an acciden:
Protecting as required

4. After an accident:
Preventing worse, helping rapidly

The new C-Class is in line with this reality-based concept, and thereby clearly distinguishes itself from all other automobiles in this market segment.

Safe driving: accident prevention with intelligent support systems

Accident prevention is the foremost principle of the Mercedes concept. With systems such as ESP®, Brake Assist and ADAPTIVE BRAKE (see page 83) as standard, the C-Class is ideally equipped for safe driving. These systems assist the driver in critical moments and help him to confidently cope with dangerous situations. Accident statistics show that the number of serious rear-end collisions and accidents caused by skidding is greatly reduced by these Mercedes technologies.

The adaptive brake light developed by Mercedes-Benz (see page 45) is also a major contribution to improved road safety. During emergency braking, the rapidly flashing brake lights of the C-Class warn drivers following behind, so that they can react more rapidly and avoid rear-end collisions. These flashing brake lights are a standard feature in the new C-Class. As an optional extra, the Saloon is also available with the latest headlamp technology from the luxury class: the Intelligent Light System includes five different lighting functions which are configured for typical driving and weather situations, giving drivers a considerably greater range of visibility. In this way the Intelligent Light System (see page 41) makes a further, important contribution to accident prevention and a reduction in the high accident risk associated with night-time journeys.

When danger threatens: debut of PRE-SAFE® in this vehicle class

One of the major aims of this commitment by Mercedes is to achieve a synergy between active and passive safety, i.e. to link accident prevention with occupant protection systems. The generic term used for this new era in vehicle safety is PRE-SAFE®. It describes an innovative protection concept based on the principle of prevention, which first entered series production in the Mercedes-Benz S-Class in 2002 and is now optionally available for the new C-Class as well. This makes the new Mercedes Saloon the only automobile in its class worldwide to feature this future-oriented safety technology.

PRE-SAFE® is linked to modern driving safety systems such as ESP® and Brake Assist, and is able to detect critical driving manoeuvres at an early stage with the help of its sensors. If the C-Class is in danger of crashing as a result of heavy under or oversteering, or if the driver needs to brake very heavily in a dangerous situation, PRE-SAFE® activates certain systems as a precaution to prepare the vehicle and its occupants for an impending accident. If a collision is avoided at the last moment, the C-Class is immediately able to continue its journey: all the PRE-SAFE® features are reversible and can be reset to their original positions, and the system is ready for use again.

This means that the passive safety phase does not only begin when the impact occurs, but before an impending collision. This Mercedes invention uses the time between the detection of a potential accident situation and a possible crash to initiate occupant protection measures.

When developing this preventive safety system, Mercedes engineers drew a distinction between critical driving manoeuvres involving large lateral and linear forces. Accordingly, precisely defined preventive measures are activated depending on the situation – and always with the aim of ensuring that well-proven safety systems such as seat belts and airbags can provide the best possible protection during an impact:

• During emergency or panic braking with Brake Assist, PRE-SAFE® tensions the seat belts as a precaution to fix the driver and front passenger in their seats, increase the distance to the dashboard and reduce the forward movement of the front seat occupants during a crash. For this important PRE-SAFE® function, the front inertia reels in the C-Class are equipped with powerful electric motors which respond within milliseconds and take up any belt slack. During emergency or panic braking, PRE-SAFE® also brings an unfavourably adjusted front passenger seat into a better position – provided the car is equipped with the electrically adjustable front passenger seat with memory function. The system corrects both the backrest and seat cushion angles, as well as the height and fore-and-aft adjustment of the seat, as required, bringing the front passenger into a position which is more advantageous for the effectiveness of the airbag and allows a good restraining effect by the shoulder belt. This also lowers the risk of sliding beneath the seat belt and sustaining injuries during an accident.
  
  
• If there is a danger of skidding owing to heavy under or oversteering, PRE-SAFE® activates a further protective function: in these situations the side windows and sliding roof begin to close as a precaution. Closed side windows are better able to support the windowbags as they deploy during a side impact or rollover. This preventive measure also lessens the risk of the occupants being thrown from the vehicle or objects penetrating into the interior during a crash. The sliding roof is linked to PRE-SAFE® because accident researchers analysing rollover accidents found that car occupants are frequently thrown out through the open roof. Closing the sliding roof as a precaution also lessens the risk of objects penetrating into the interior.

Measurements taken by Mercedes engineers during crash tests show how effective preventive occupant protection can be in an accident. Take the belt tensioners, for example: because the driver and front passenger are optimally held in their seats and do not move as far forward during an impact, the loads acting on the head and neck areas are reduced. Tests showed that the head was subjected to around 30 percent lower loads, while the reduction for the neck area was around 40 percent.

During an accident: occupant protection on four levels

During the course of its development, the new C-Class successfully passed more than 100 crash tests, including not just the over 2 dozen different crash tests for the saloon to meet worldwide requirements, but also 9 particularly demanding, in-house impact tests of which some go well beyond the legal requirements. Passing these is a precondition for the highest accolade in automobile safety: the Mercedes star.

And finally the C-Class has absolved around 5500 computer-based crash tests – realistic simulations which provided the engineers with particularly valuable information during the early project phase.

Following this time-consuming and painstaking development work, the new C-Class is outstandingly well prepared for the accident situations that actually occur on our roads:

Frontal impact:

Compared to the previous series, Mercedes-Benz has enlarged the deformation zones even further and improved energy flows. The front-end structure of the new C-Class has four independently acting impact levels, which enable forces to be distributed over a wide area while bypassing the passenger cell. In addition to the robust aluminium cross-member in the front end, and side members which extend well forward to direct impact forces into the side structure, firewall and transmission tunnel, the integral support of high-strength steel now also absorbs these forces. For this purpose it has been extended forward and connected to the newly developed floor side members (see page 34) via special tubular members. During a crash this enables the integral support to deform and absorb energy, while also transferring large impact forces directly into the vehicle floor. Robust profiled steel panels above the wheel arches form the second side member level. These panels are connected to the A-pillars.

During an offset frontal crash, the extended side skirts support the wheel and prevent it from intruding into the footwell. This also allows additional energy absorption via the wheels.

To provide specific support and guidance to the front wheels, Mercedes-Benz has also developed special struts and additional impact-absorbing element in the wheel arches. These struts are arranged diagonally and prevent the passenger cell from dropping during a collision, enabling the C-Class to absorb the impact energy and protect its occupants even more effectively. As another new feature on the driver’s side, an X-strut connects the shock absorber tower with the strong cross-member beneath the windscreen and supports it. During an impact, this strut prevents the shock absorber tower and the main brake cylinder behind it, to which the pedals are in turn linked, from moving to the rear. This strut made from ultra high-strength steel therefore has a dual function: it reduces the loads acting on the firewall and prevents the pedal cluster from being pushed into the interior. Mercedes-Benz has also developed the steering further. This is equipped with an energy-absorbing element which allows the steering column to collapse telescopically by up to 100 millimetres during a frontal collision, enabling the driver to benefit from a longer deceleration path.

Side impact:

As only a very small crumple zone is available during a side collision, Mercedes engineers were careful to ensure that the impact forces are widely distributed. The four-layered B-pillars and the side members (sills) play the main part in this. Both components are partly made from ultra high-strength, hot-formed high-tech steel (see page 34). The impact forces are substantially transferred from the B-pillar to the unaffected side of the vehicle via the transversely rigid seat and the centre console. Accordingly the seats of the C-Class are equipped with tubular sections and impact-absorbing elements in the side mouldings.

Another load dissipation path runs from the base of the B-pillars to the cross-member under the seats and the tunnel struts (see page 34). The B-pillars are also able to transmit forces to the roof frame. At medium height, the doors with their rigid waistline sections and bonded-in reinforcing panels form a strong integrated structure (see page 35).

Rear impact:

An effective deformation zone is also available at the rear end of the new C-Class. This mainly consists of multi-piece side members and a bolted-in cross-member, which is able to absorb large forces and distribute them into the body structure. The fuel tank is located in a protected position beneath the rear seat unit.

Passenger cell:

While the different load-bearing structures at the front, sides and rear end of the Saloon are designed to deform and absorb energy during an impact, the passenger cell acts as the "hard core" of the safety concept in the C-Class. Even in a serious accident it only deforms very slightly, maintaining the survival space of the occupants. Mercedes engineers have achieved this by the use of high-strength and ultra high-strength steel alloys (see page 33) with graduated wall thicknesses, as well as by developing an extremely strong floor structure. This comprises two continuous side members, several cross-members and two tunnel struts which are able to transfer side impact forces to the unaffected side of the vehicle.

Protective systems: seven airbags as standard

In the interior, the exemplary safety technology of the new C-Class is complemented with the very latest protective systems. Three-point inertia-reel seat belts with belt tensioners and belt force limiters are fitted as standard for the driver, front passenger and occupants of the outer rear seats. Forces are dissipated on an adaptive basis in the front: after reaching a certain maximum retention, the belt forces are reduced to a low level – the belts are allowed to slacken so that the occupants are more deeply immersed in the deploying airbags, reducing the loads acting on the torso.

In addition the new C-Class is equipped with seven airbags as standard: two adaptive airbags for the driver and front passenger, a kneebag for the driver, two sidebags in the front seat backrests and two large windowbags which extend from the A to the C-pillar during a side impact.

The highly effective, automatic child seat recognition system is also available as an optional extra. This deactivates the front passenger airbag as soon as a reboard child seat equipped with a transponder is detected.

The front airbags are activated in two stages, depending on the severity of the impact. The front end of the new C-Class is equipped with two up-front sensors. By virtue of their exposed position on the front-end module, these are able to detect the severity of a collision at an early stage. This information enables the time between the crash and activation of the airbags and belt tensioners to be reduced even further. The belts can therefore be tensioned at a very early stage, so that the occupants are connected to the passenger cell during an impact and can take part in the deceleration of the body structure. During a less serious accident only the first stage of the airbag generators is triggered, and the airbags are only partially inflated for a "soft landing". If the impact is more severe, the second stage of the airbag generator is also activated and fully inflates the airbags.

The sensor system for side impacts is also more sophisticated than in the preceding model. Innovative pressure sensors rapidly and precisely inform the control unit about a side collision in the area of the doors. These sensors react when the air between the outer and inner skins of the doors is compressed during a crash. Additional side sensors are installed in the B-pillars.

NECK-PRO is another special safety feature in the new C-Class. This is the name Mercedes-Benz has given to a crash-responsive head restraint whose development, like that of PRE-SAFE® and other Mercedes innovations, is based on analyses of real accidents. NECK-PRO is an effective means of reducing the risk of whiplash injuries during a rear-end collision. If the sensor system detects a rear-end collision with a defined impact severity, it releases pre-tensioned springs inside the head restraints which immediately cause these to move forward within milliseconds by about 40 millimetres and upwards by 30 millimetres. This means that the heads of the front occupants are supported at an early stage.

After NECK-PRO activation the head restraints can be unlocked and returned to their original position using a tool supplied with the car, and are then immediately ready for use again. NECK-PRO head restraints for the driver and front passenger are standard equipment in the new C-Class.

The standard occupant restraint system at a glance:

• = standard
  
  

After an accident: innovative safety fuses as a fire precaution

The aim during this safety phase is to avoid even more serious consequences and recover accident victims as quickly as possible. In order to prevent consequential damage, the fuel supply to the engine is automatically interrupted if the new C-Class is involved in an accident of sufficient severity. The hazard warning system is also switched on to warn following traffic and prevent further accidents. After an accident with airbag activation, all the side windows are opened very slightly to ventilate the interior. The doors are also automatically unlocked so that helpers are able to recover injured passengers more rapidly.

Specially designed crash joints prevent the doors from being jammed shut by the wings. The occupants are also able to open the doors after an accident, as Mercedes-Benz uses Bowden cables, which usually remain intact after deformation, to operate the door catches from the inside.

To prevent electrical short-circuits and therefore a possible fire, the C-Class is equipped with a special safety fuse in the cable connection between the battery and the starter generator. After a serious accident this interrupts the power supply by pyrotechnical action, though the remaining onboard network remains intact.

Pedestrian protection: deformation zones under the bonnet

Pedestrian protection was another major topic in the safety development activities for the new C-Class. This is not a new area for Mercedes-Benz, as the company has long concerned itself with reducing the risk of injury to the most vulnerable of all road users – pedestrians and (motor) cyclists. Smooth body surfaces, energy-absorbing bumpers, laminated glass windscreens, folding exterior mirrors, rounded door handles and recessed windscreen wipers are just some of the details that serve this purpose. Mercedes innovations in the active safety field such as Brake Assist also make a major contribution to pedestrian protection, as they help to prevent accidents with pedestrians from occurring in the first place, or significantly reduce the impact speed. This has been confirmed by the latest accident research findings.

To reduce the risk of injury to pedestrians, the bonnet of the new C-Class is designed to deform under a head impact. The deformation space between the bonnet and the components beneath it has been enlarged in two ways: firstly by the higher external contours of the Saloon, and secondly by the lower location of the engine, shock absorber towers, containers and control units.

The front bumper features a flush, foam-filled spoiler lip which provides a pedestrian with consistent support at an early stage during a collision.

Repair concept: lower costs by virtue of intelligent body engineering

Energy-absorbing plastic bumpers, bolted connections for the front and rear-end modules and crash boxes are the major components of a sophisticated concept which helps to reduce the cost of accident repairs. The components are specifically designed to absorb energy during a low-speed crash so that the body structure itself is protected against damage. Further examples of the repair-friendly bodyshell concept:

• The plastic front bumper with integral foam elements absorbs impact energy at speeds up to approx. four km/h. The absorbent material automatically returns to its former shape after the crash.
  
  
• Bolted to the bodyshell, the front end mainly consists of an extruded aluminium cross-member with two aluminium crash boxes. Their strength and energy absorption are precisely calculated to ensure that at an impact speed of up to 15 km/h against a rigid barrier, any deformation is limited to bolt-on front-end components. All the components of this module are bolted together, and can therefore be replaced without troublesome welding work (see page 33).
  
• The rear bumper has the same elastic deformation characteristics as its opposite number in the front, and remains undamaged after impacts at speeds up to four km/h.
  
• The rear-end module of the new C-Class consists of a solid, flexible cross-member and a steel crash box, both of them bolted to the body structure. This module almost completely absorbs crash energy at collision speeds up to approx. 15 km/h.
  
  
  

The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.



The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The C-Class has completed about 5500 crash tests on the computer - true-to-life simulations, which provided engineers with useful insights particularly in the initial project phase. Mercedes-Benz uses one of the world's largest IT networks for these kinds of crash simulations, a process that involves computers carrying out up to 320 billion computing operations. Over 1500 processors were used as part of developing the safety systems for the C-Class.


The B-pillars, which have to absorb high forces and transfer them into into the structure of the bodywork, consist of three such sheet metal layers, or shells, together with a large reinforcement which extends up to the top of the seat belt sash guide. The reinforcement and one of the shells are made of ultra-high-strength, hot-formed steel.


The seats on the C-Class are fitted with high-strength tubular sections and impact-absorbing elements in the side trim. In the event of a side impact, the forces can be transferred via the seat and the centre console to the non-impacted side of the vehicle.


Apart from the robust aluminium cross-member on the front end and longitudinal members that extend a long way forward, which divert the forces into the side structure, the bulkhead and the centre tunnel, for the first time the integral, high-strength steel subframe acts as a loading case level. It was therefore extended forward and joined to the newly developed longitudinal floor members using special supporting tubes.


Throughout the development cycle, the new C-Class completed over 100 crash tests. This rigorous testing programme not only included more than two dozen different impact configurations, laid down as part of the car's global certification programme, but also nine particularly demanding in-house crash tests, some of which push the car far beyond any applicable legal requirements.


Throughout the development cycle, the new C-Class completed over 100 crash tests. This rigorous testing programme not only included more than two dozen different impact configurations, laid down as part of the car's global certification programme, but also nine particularly demanding in-house crash tests, some of which push the car far beyond any applicable legal requirements.


Throughout the development cycle, the new C-Class completed over 100 crash tests. This rigorous testing programme not only included more than two dozen different impact configurations, laid down as part of the car's global certification programme, but also nine particularly demanding in-house crash tests, some of which push the car far beyond any applicable legal requirements.


Throughout the development cycle, the new C-Class completed over 100 crash tests. This rigorous testing programme not only included more than two dozen different impact configurations, laid down as part of the car's global certification programme, but also nine particularly demanding in-house crash tests, some of which push the car far beyond any applicable legal requirements.


Throughout the development cycle, the new C-Class completed over 100 crash tests. This rigorous testing programme not only included more than two dozen different impact configurations, laid down as part of the car's global certification programme, but also nine particularly demanding in-house crash tests, some of which push the car far beyond any applicable legal requirements.


Seven airbags are standard equipment in the C-Class: two adaptive airbags for driver and front passenger, a kneebag for the driver (in the Euro NCAP countries), two sidebags in the backrests of the front seats and two large windowbags, which extend from the A-pillar to the C-pillar in the event of a side impact.


Seven airbags are standard equipment in the C-Class: two adaptive airbags for driver and front passenger, a kneebag for the driver (in the Euro NCAP countries), two sidebags in the backrests of the front seats and two large windowbags, which extend from the A-pillar to the C-pillar in the event of a side impact.


Seven airbags are standard equipment in the C-Class: two adaptive airbags for driver and front passenger, a kneebag for the driver (in the Euro NCAP countries), two sidebags in the backrests of the front seats and two large windowbags, which extend from the A-pillar to the C-pillar in the event of a side impact.


Crash-responsive NECK-PRO head restraints are part of the standard specification for the new C-Class. Once the sensors have determined that a rear-end collision has occurred and that the impact has exceeded a defined level, the pre-stressed springs inside the head restraints are released. As a result, the padded surface of the head restraint is shifted some 40 millimetres forward and 30 millimetres upward within a split second, providing the heads of the front-seat passengers with support at an early stage.


Crash-responsive NECK-PRO head restraints are part of the standard specification for the new C-Class. Once the sensors have determined that a rear-end collision has occurred and that the impact has exceeded a defined level, the pre-stressed springs inside the head restraints are released. As a result, the padded surface of the head restraint is shifted some 40 millimetres forward and 30 millimetres upward within a split second, providing the heads of the front-seat passengers with support at an early stage.


The adaptive brake light developed by Mercedes-Benz is an important contribution to improved road safety. During emergency braking, the C-Class warns drivers behind by flashing the brake lights rapidly so they can react faster and avoid a rear-end collision.


PRE-SAFE is networked with state-of-the-art safety systems such as ESP and Brake Assist and, thanks to its sensors, can recognise a potentially dangerous driving manoeuvre in its early stages. If the vehicle is likely to be involved in an accident as a result of heavy understeer or oversteer or the driver has to brake hard in an emergency, PRE-SAFE activates a series of preventive measures to prepare both the occupants and the vehicle for a possible collision.


PRE-SAFE is networked with state-of-the-art safety systems such as ESP and Brake Assist and, thanks to its sensors, can recognise a potentially dangerous driving manoeuvre in its early stages. If the vehicle is likely to be involved in an accident as a result of heavy understeer or oversteer or the driver has to brake hard in an emergency, PRE-SAFE activates a series of preventive measures to prepare both the occupants and the vehicle for a possible collision.


The anticipatory protection system PRE-SAFE is available as an option for the C-Class. As such, the new Mercedes Saloon is the only car in the world in its class with this leading-edge safety technology.


The new C-Class has four independent impact levels - impact forces can therefore be distributed over a large area and away from the passenger cell.



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