The Mercedes-Benz C-Class, a popular luxury sedan, underwent redesigns for the 2008 model year. Significant safety enhancements were introduced over the years, including a driver’s knee airbag in 2010 to bolster frontal crash protection. For 2013 models manufactured after December 2012, a crucial update was implemented: the side curtain airbags were reprogrammed. This reprogramming aimed to optimize deployment in small overlap frontal crashes, offering improved occupant safety. It’s important to note that the manufacturing date for specific vehicles can be found on the certification label, typically located on or near the driver’s side door.
To assess the impact of these airbag system changes, the Insurance Institute for Highway Safety (IIHS) conducted two small overlap frontal crash tests on the C-Class. The first test involved a 2012 model, while the second test utilized a 2013 model produced after the airbag reprogramming in December 2012. Notably, in the initial test, the driver’s side curtain airbag did not deploy as intended. However, in the subsequent test with the updated system, the airbag deployed correctly. The official ratings and vehicle specifications are based on this second, more representative test. Despite the airbag system update, the fundamental vehicle structure remained unchanged, and therefore the structural rating considers data from both tests.
The 2014 Mercedes-Benz C-Class achieved the following ratings in the small overlap frontal crash test:
| Evaluation criteria | Rating |
|---|---|
| Structure and safety cage | P |
| Driver injury measures | |
| Head/neck | G |
| Chest | G |
| Hip/thigh | G |
| Lower leg/foot | P |
| Driver restraints and dummy kinematics | G |
These results indicate a mixed performance in the small overlap frontal crash scenario. The C-Class demonstrated “Good” protection for the head, neck, chest, and hip/thigh areas. This signifies that the restraints and airbags effectively mitigated injury risks to these critical body regions. However, the “Marginal” rating for structure and safety cage, combined with a “Poor” rating for lower leg/foot injury measures, raises concerns.
Analysis of the crash tests revealed that the driver’s survival space was compromised due to significant footwell intrusion. This intrusion, as depicted in the technical measurements, contributed to an elevated risk of injury to the lower extremities.
Conversely, the frontal and side curtain airbags demonstrated effective coordination in containing the driver’s head, minimizing the risk of contact with hard structures or external objects. This highlights the positive impact of the airbag system, particularly the reprogramming implemented for the 2013-2014 models.
Despite the effective upper body protection, the extensive intrusion into the driver’s footwell in both tests posed a considerable threat to the lower legs. The risk of injury to the left lower leg was deemed high, with at least a significant risk to the right lower leg. Furthermore, in both tests, the dummy’s right foot became trapped by intruding structure and the brake pedal, caused by the left front wheel being forced rearward and inward upon impact.
Technical Measurements:
Measures of occupant compartment intrusion on driver side (cm)
| Evaluation criteria | Measurement (CEN1211) | Measurement (CEN1327) |
|---|---|---|
| Lower occupant compartment | ||
| Lower hinge pillar max | 9 | 12 |
| Footrest | 32 | 50 |
| Left toepan | 24 | 29 |
| Brake pedal | 21 | 22 |
| Parking brake | 14 | 20 |
| Rocker panel lateral average | 0 | 1 |
| Upper occupant compartment | ||
| Steering column | 4 | 4 |
| Upper hinge pillar max | 9 | 11 |
| Upper dash | 11 | 10 |
| Lower instrument panel | 11 | 11 |
Driver injury measures
| Evaluation criteria | Measurement (CEN1327) |
|---|---|
| Head | |
| HIC-15 | 248 |
| Peak gs at hard contact | no contact |
| Neck | |
| Tension (kN) | 0.8 |
| Extension bending moment (Nm) | 9 |
| Maximum Nij | 0.15 |
| Chest maximum compression (mm) | 20 |
| Femur (kN) | |
| Left | 4.9 |
| Right | 3.2 |
| Knee displacement (mm) | |
| Left | 3 |
| Right | 3 |
| Knee-thigh-hip injury risk (%) | |
| Left | 3 |
| Right | 1 |
| Maximum tibia index | |
| Left | 2.14 |
| Right | 1.13 |
| Tibia axial force (kN) | |
| Left | 10.6 |
| Right | 4.1 |
| Foot acceleration (g) | |
| Left | 147 |
| Right | 98 |
In conclusion, the 2014 Mercedes-Benz C-Class demonstrates robust protection for the head, neck, chest, and upper legs in small overlap frontal crashes. However, the structural deficiencies leading to footwell intrusion present a significant vulnerability for lower leg and foot injuries. Prospective buyers should consider these findings in their vehicle safety assessments.
