Safety: Innovations borrowed from the luxury class

  • First car in its class with PRE-SAFE®
  • Front-end impact zones on multiple levels
  • Seven airbags and NECK-PRO head restraints as standard
  • Elaborate load-securing measures
Nothing beats experience – except even more experience. With every new model, Mercedes-Benz enriches its 60 plus years of expertise in the field of passenger car safety, it translates the latest findings from real-life accidents into concrete protective measures and it pioneers new driver assistance systems to make motoring even safer.
The new C-Class likewise represents a further significant advance for Mercedes-Benz in its ongoing quest for safety. Once again, the engineers in Sindelfingen have learned more from their accident research, once again their exhaustive testing work has helped to further improve occupant protection, and once again they have ensured that even more drivers benefit from the cutting-edge technology inherited from 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 in an anticipatory manner with PRE-SAFE®
3. During an accident: Protecting as required
4. Following an accident: Preventing worse, helping rapidly
Safe driving: accident prevention with intelligent assistance systems
Accident prevention is the foremost principle of the Mercedes concept. With systems such as ESP®, Brake Assist and ADAPTIVE BRAKE as standard, the new C‑Class Estate is ideally equipped for safe driving. The adaptive brake light developed by Mercedes-Benz is another major contribution to improved road safety. During emergency braking, the Estate's rapidly flashing brake lights warn drivers following behind, so that they react faster and rear-end collisions can be avoided. These flashing brake lights are a standard feature.
As an optional extra, the Estate 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 and considerably increase the driver's range of vision. In this way, the Intelligent Light System makes a further, vital contribution both to accident prevention and to reducing the high accident risk associated with night-time journeys.
When danger threatens: anticipatory occupant protection with PRE-SAFE®
One of the major aims of this commitment by Mercedes is to achieve a synergy between active and passive safety, i.e. to interlink accident prevention systems with occupant protection . 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 the new C-Class Estate as well. This makes it the only automobile in its class worldwide to feature this future-oriented safety technology.
PRE-SAFE® is linked up to sophisticated active safety systems such as ESP® and Brake Assist, and is able to detect critical driving manoeuvres at an early stage with the help of their sensors. If the car is in danger of crashing as a result of heavy understeer or oversteer, or if the driver needs to brake very heavily in a hazardous situation, PRE-SAFE® triggers certain measures as a precaution to prepare the vehicle and its occupants for an impending accident. If a collision is averted 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, after which the system is ready for use again.
This means that the passive safety phase does not only begin when the impact occurs, but in advance of an imminent 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 anticipatory safety system, Mercedes engineers drew a distinction between critical driving manoeuvres involving high lateral and extreme 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 in the event of an impact:
  • During emergency or panic braking with Brake Assist, PRE-SAFE® pulls the seat belts taut as a precaution to fix the driver and front passenger securely 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® furthermore starts by bringing 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 favourable from the point of view of airbag effectiveness and which allows the shoulder belt to exert a good restraining effect. This also lowers the risk of sliding beneath the seat belt strap and sustaining injuries during a collision.
  • If there is a danger of skidding owing to heavy understeering or oversteering, PRE-SAFE® activates a further protective function: in these situations the side windows and sliding sunroof begin to close as a precaution. Closed side windows are better able to brace the windowbags which deploy during a side impact. 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 sunroof is linked to PRE-SAFE® because accident researchers analysing rollover accidents frequently find that car occupants can be completely or partially thrown out of the vehicle through the open roof. Closing the sliding sunroof as a precaution also reduces the risk of objects penetrating into the interior.
Measurements taken by Mercedes engineers during crash tests show how important and effective anticipatory occupant protection can be in an accident. Take the seat belt tensioning, for example: because driver and front passenger are secured in their seats as best possible by this precautionary measure, and do not move as far forward during the impact, the loads exerted in the head and neck areas are reduced. Tests showed that the head was subjected to around 30 per cent less stress, while the reduction in the neck area was around 40 per cent.
During an accident: occupant protection on multiple levels
Over the course of its development, the new C-Class Estate completed over 100 crash tests in all -- including not just the two dozen plus crash configurations needed to obtain its worldwide licence, but a further nine highly demanding, in-house crash tests, some of which go well beyond the statutory requirements. In addition to this, the C-Class Saloon and Estate were put through their paces in around 5500 computerised crash tests – realistic simulations which provided the engineers with particularly valuable information during the early stages of the project.
Following such time-consuming and painstaking development work, the new Estate is outstandingly well prepared for the accident situations that actually occur on our roads:
  • · Frontal impact:

    Compared to the previous series, which itself offered excellent protection, Mercedes-Benz has further enlarged the deformation zones and optimised energy flows again. Like the C-Class Saloon, the new Estate features 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, these forces are for the first time absorbed by the subframe made of high-strength steel too. For this purpose it has been extended forward and connected to the newly developed floor side members via special support tubes. During a crash this enables the subframe to both deform in a predetermined manner and absorb energy, while also transferring high impact forces directly into the vehicle floor.

    In order to purposefully support and guide the front wheels, Mercedes-Benz developed special struts and additional impact-absorbing elements 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 robust cross member beneath the windscreen and supports it. During an impact, this strut reduces the rearwards displacement of the shock absorber tower and the main brake cylinder behind it, to which the pedals are attached. This strut made from ultra-high-strength steel therefore has a dual function: it both lessens the loads acting on the firewall and prevents the pedal cluster from being pushed into the interior.
  • 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 distributed over a wide area. The quadruple-shell B-pillars and the side members along the vehicle's flanks (sills) are mainly responsible for this. Both components are partly manufactured from ultra-high-strength, hot-formed high-tech steel. The impact forces are transferred from the B-pillar to the opposite side of the vehicle first and foremost 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. A futher load dissipation path runs from the base of the B-pillars to the cross member under the seats and the transmission tunnel braces. The B-pillars are also able to transmit forces to the roof frame. At the middle level, the doors with their rigid beltline sections and bonded-in reinforcing panels form a sturdy integrated structure.
  • Rear impact:

    An effective crumple zone is also included at the rear end of the new C-Class Estate. This basically consists of multi-piece side members and a bolted-in section that acts as a cross member capable of absorbing large forces and distributing 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 Estate 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 to maintain the survival space of the occupants intact. Mercedes engineers have achieved this both by making increased use of high-strength and ultra-high-strength steel grades with graduated wall thicknesses, and by developing an extremely strong floor assembly. This comprises two continuous side members, several transverse sections, as well as two transmission tunnel braces which are able to transfer forces released in a side impact to the unaffected side of the vehicle.
Protective systems: seven airbags as standard
In the interior, the exemplary safety technology of the new Estate is complemented by sophisticated 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 the occupants of the outer seats in the rear. Force limitation is performed on an adaptive basis in the front: after reaching a certain maximum retention, the belt force is reduced to a lower level – the belts are allowed to slacken so that the occupants can sink deeper into the airbags as they deploy, reducing the strain exerted on the torso.
The vehicle's standard specification furthermore comprises a total of seven airbags: two adaptive airbags for the driver and front passenger, a kneebag for the driver (in Europe), two sidebags in the front seat backrests plus two large windowbags which extend from the A to the C-pillar in a side impact.
The front airbags are activated in two stages, depending on the severity of the impact. Two up-front sensors are installed in the front-end structure of the C-Class, whose forwards positioning allows a collision to be detected at an early stage. This information reduces the time between the point of impact and activation of the airbags and belt tensioners. In a less serious accident, only the first stage of the airbag generators is triggered so that the airbags inflate partially for a "soft landing". If the impact is more severe, the second stage of the airbag generator is also detonated to fully inflate the airbags.
The sensor system for side impacts is also more sophisticated than in the preceding model. Innovative new pressure sensors relay rapid, precise information to the control unit in the event of a collision from the side in the area of the doors. These sensors react when the air between the doors' outer skin and inner lining is compressed on impact. Additional side sensors are installed in the B-pillars.
Head restraints: crash-responsive NECK-PRO system as standard
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 actual 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, projecting the head restraints' padded surfaces forwards by about 40 millimetres and upwards by 30 millimetres within a matter of milliseconds. This means that the heads of the occupants in the front are supported at an early stage. Following a NECK-PRO deployment, the head restraints can be returned to their original position manually 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 Estate.
The standard occupant restraint system at a glance:
 
Front seats
Rear seats
Inertia-reel seat belts with height adjustment
  •  
  • height adjustment for the outer seats
Belt tensioners
  •  
  • for the outer seats
Belt force limiters
  • with adaptive control
  • for the outer seats
Head restraints
  • with NECK-PRO function
  •  
Front airbags, two-stage
  •  
Sidebags
  •  
  • optional
Windowbags
  •  
  •  
Kneebag*
  • on driver’s side
· = standard; *in Europe
 
The integrated child seat developed by Mercedes-Benz, which folds out of the rear seat at the push of a button, has been further improved by the engineers in Sindelfingen. It now comes with a supplementary wraparound head restraint, which can be attached to the head restraint on the rear seat backrest. The integrated child seat is suitable for passengers aged between two and twelve, and can be factory-fitted as an option.
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 child seat equipped with a transponder is detected.
Load restraint: combined luggage cover and retaining net as standard
The topic of load restraint has traditionally played an important role in the development of estate models from Mercedes. And with good reason too: items of luggage or any other objects lying in the load compartment can suddenly pose a major hazard in an accident. In an impact against a rigid wall at a speed of 50 km/h, Mercedes engineers have measured deceleration rates of as much as 30 g, in other words 30 times the acceleration due to gravity. In such a collision, a suitcase weighing 20 kilograms would therefore have an actual "impact weight" of some 600 kilograms.
In view of this, Mercedes-Benz equips the new C-Class Estate with an extremely sturdy rear seat backrest which is able to withstand high impact loads in a crash, as are its locking points and catches. Not only does the backrest incorporate a frame section built of high-strength steel, the load compartment floor is also made from robust material and is additionally secured by two hinge hooks and a locking bar. By no means are such safety features always the norm on other estate cars.
The same applies to the two-section roller unit, containing firstly a luggage cover and secondly a retaining net which can be pulled upwards as a partition between the passenger and load compartments. This net is capable of holding back any items of luggage placed above the top edge of the rear seat backrest which are propelled forwards in a collision. The luggage cover and partition net are included on the C-Class Estate as standard.
Securely strapping down the load is every bit as important, however. This is where the four load-securing rings fitted as standard in the Estate's load compartment floor come into their own. By hooking tensioning straps into these rings, suitcases and other items can be lashed firmly into place. And for even more ways of making the vehicle's load safe, there is the option of the new EASY-PACK system.
After the accident: innovative safety fuses as a fire precaution
The aim during this safety phase is to prevent anything worse form happening and recover accident victims as quickly as possible. For instance, the fuel supply to the engine is automatically interrupted on the new C-Class Saloon and Estate if they are involved in an accident of sufficient severity, while the hazard warning lamps are also switched on to warn traffic behind and prevent any further accidents. Following an accident in which the front airbags are deployed, the front windows are opened very slightly to ventilate the interior. The doors are also automatically unlocked to expedite the rescue of injured passengers. In addition to this, the interior lights are switched on automatically.
Specially designed crash joints prevent the doors from being wedged shut in an impact. The occupants are also able to open the doors after an accident, as Mercedes-Benz uses Bowden cables -- which usually remain intact after deformation -- for operating the door catches from the inside.
Pedestrian protection: deformation zones under the bonnet
Another focus of development for the safety systems of the C-Class was the issue of pedestrian protection. This is nothing new 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 field of active safety, 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 – something which has recently been confirmed by analyses of accident statistics.
To reduce the risk of injury to pedestrians, the bonnet is designed to deform upon head impact. The deformation space between the bonnet and the assemblies beneath it has been enlarged in two ways: firstly by the vehicle's higher external contours, and secondly by the lower positioning of the engine, shock absorber towers, reservoirs and control units. The front bumper features a flush, foam-filled spoiler lip which provides a pedestrian with uniform support at an early stage in a collision.
Repair concept: lower costs by virtue of intelligent body engineering
Energy-absorbing plastic bumpers, bolted connections at the front and rear, along with crash boxes are the principal elements of an ingenious concept which helps to reduce the cost of accident repairs. The components are designed to absorb energy during a low-speed impact in a predefined manner, so as to protect the actual bodyshell structure against damage. Further examples of the body's easy-to-repair concept include:
  • The plastic front bumper has built-in foam elements to absorb the impact energy in collisions at speeds up to four km/h. The flexible material automatically returns to its original form after the crash.
  • Bolted to the bodyshell, the front-end assembly 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 the need for laborious welding work.
  • The rear bumper has the same elastic deformation properties as its opposite number at the front, and remains undamaged in collisions at speeds up to four km/h.
  • The rear-end module consists of a solid, flexible cross member and a crash box, both made of steel and bolted to the body structure. This module almost completely absorbs impact energy at collision speeds up to approx. 15 km/h.

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    Mercedes-Benz C-Class Estate: The tying down of cargo has traditionally played an important role in the development of Mercedes estate vehicles. For this reason, Mercedes-Benz has equipped its new C-Class Estate with a very sturdy rear seat backrest which is capable of withstanding extreme loading during a crash. The standard equipment includes the two-section roller blind, which contains both a load compartment cover and a partition net that can be fitted between passenger area and load compartment. The standard equipment also includes four load-securing rings in the load compartment floor.
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    Mercedes-Benz C-Class Estate: The tying down of cargo has traditionally played an important role in the development of Mercedes estate vehicles. For this reason, Mercedes-Benz has equipped its new C-Class Estate with a very sturdy rear seat backrest which is capable of withstanding extreme loading during a crash. The standard equipment includes the two-section roller blind, which contains both a load compartment cover and a partition net that can be fitted between passenger area and load compartment. The standard equipment also includes four load-securing rings in the load compartment floor.
  • 07c1287_058
    Mercedes-Benz C-Class Estate: The tying down of cargo has traditionally played an important role in the development of Mercedes estate vehicles. For this reason, Mercedes-Benz has equipped its new C-Class Estate with a very sturdy rear seat backrest which is capable of withstanding extreme loading during a crash. The standard equipment includes the two-section roller blind, which contains both a load compartment cover and a partition net that can be fitted between passenger area and load compartment. The standard equipment also includes four load-securing rings in the load compartment floor.
  • 07c1287_118
    Mercedes-Benz C-Class Estate: The tying down of cargo has traditionally played an important role in the development of Mercedes estate vehicles. For this reason, Mercedes-Benz has equipped its new C-Class Estate with a very sturdy rear seat backrest which is capable of withstanding extreme loading during a crash. The standard equipment includes the two-section roller blind, which contains both a load compartment cover and a partition net that can be fitted between passenger area and load compartment. The standard equipment also includes four load-securing rings in the load compartment floor.
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    Mercedes-Benz C-Class Estate: The new Estate is the safest automobile in its class. Its occupants are protected by a total of seven standard-equipment airbags. Belt tensioners and belt force limiters are available for driver, front passenger and outside rear passengers; and the front NECK-PRO head restraints are crashactive.
  • 07c1287_227
    Mercedes-Benz C-Class Estate: The integral child seat developed by Mercedes-Benz, which folds down out of the rear seat at the press of a button, has been yet further improved by the engineers in Sindelfingen. It is now equipped with an additional side head restraint which is secured to the head restraints on the rear seat backrest.
  • 07c1287_225
    Mercedes-Benz C-Class Estate: The integral child seat developed by Mercedes-Benz, which folds down out of the rear seat at the press of a button, has been yet further improved by the engineers in Sindelfingen. It is now equipped with an additional side head restraint which is secured to the head restraints on the rear seat backrest.
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