The Mercedes-Benz C-Class, a popular choice in the UK for its blend of luxury and performance, has consistently been a focus for safety evaluations. This article delves into the safety performance of the 2021 Mercedes-Benz C-Class, drawing upon rigorous testing data to provide a clear picture for prospective buyers and safety-conscious drivers. We’ll explore various crash test scenarios and safety feature assessments to understand how well this vehicle protects its occupants.
Small Overlap Front Crash Test: Driver-Side Insights
The small overlap front crash test is designed to simulate what happens when the corner of a vehicle collides with a narrow object like a tree or pole. For the driver-side assessment of the 2021 Mercedes-Benz C-Class (models from 2015-21), the results provide valuable insights into occupant protection.
The C-Class earned a “Good” rating in the small overlap front: driver-side test, the highest possible rating. This indicates robust structural integrity and effective safety measures.
| Evaluation criteria | Rating |
|---|---|
| Structure and safety cage | Good |
| Driver injury measures – Head/Neck | Good |
| Driver injury measures – Chest | Good |
| Driver injury measures – Hip/Thigh | Good |
| Driver injury measures – Lower Leg/Foot | Good |
However, there was an “Acceptable” rating for driver restraints and dummy kinematics. The test noted that while the dummy’s head contacted the frontal airbag, it rolled to the left due to excessive forward movement allowed by the seat belt. Despite this, the side curtain airbag deployed effectively, offering substantial head protection.
Action shot during the small overlap frontal crash test of the Mercedes-Benz C-Class, highlighting vehicle deformation and airbag deployment.
Post-crash analysis of the dummy’s position showed that the driver’s survival space was well-maintained. This is a critical factor in real-world accident scenarios, suggesting a strong safety cage design in the 2021 Mercedes-Benz C-Class.
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Post-crash dummy position inside the 2021 Mercedes-Benz C-Class, showing good survival space maintenance and airbag effectiveness.
Despite the overall “Good” rating, the slight head roll of the dummy towards the gap between the frontal and side curtain airbags is noted. This indicates an area for potential improvement in restraint systems in future models.
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Close-up of dummy head movement during the crash test, indicating slight roll towards the side airbag gap in the 2021 Mercedes-Benz C-Class.
Measurements from the test confirm good maintenance of the driver’s space, reinforcing the low risk of leg and foot injuries in this type of collision for the 2021 Mercedes-Benz C-Class.
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Driver’s side footwell area post-small overlap crash test, showing minimal intrusion and indicating low risk of lower extremity injuries in the 2021 Mercedes-Benz C-Class.
Technical measurements from the driver-side small overlap test are detailed below:
Measures of occupant compartment intrusion (driver side)
| Evaluation criteria | Measurement (cm) |
|---|---|
| Lower hinge pillar max | 5 |
| Footrest | 10 |
| Left toepan | 5 |
| Brake pedal | 8 |
| Rocker panel lateral average | 2 |
| Steering column | 1 |
| Upper hinge pillar max | 4 |
| Upper dash | 4 |
| Lower instrument panel | 4 |
Driver injury measures
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 161 |
| Neck Tension (kN) | 1.0 |
| Neck Extension bending moment (Nm) | 5 |
| Maximum Nij | 0.20 |
| Chest maximum compression (mm) | 21 |
| Femur Left (kN) | 1.2 |
| Femur Right (kN) | 1.3 |
| Knee displacement Left (mm) | 3 |
| Knee displacement Right (mm) | 5 |
| Knee-thigh-hip injury risk (%) Left | 0 |
| Knee-thigh-hip injury risk (%) Right | 0 |
| Maximum tibia index Left | 0.50 |
| Maximum tibia index Right | 0.43 |
| Tibia axial force Left (kN) | 2.8 |
| Tibia axial force Right (kN) | 2.4 |
| Foot acceleration Left (g) | 80 |
| Foot acceleration Right (g) | 73 |
Small Overlap Front Crash Test: Passenger-Side Performance
The passenger-side small overlap test evaluates protection for the front passenger in a similar narrow offset frontal collision. Applicable to 2019-21 models, the 2021 Mercedes-Benz C-Class again demonstrated excellent safety performance.
The 2021 C-Class achieved an overall “Good” rating for passenger-side small overlap protection, mirroring the driver-side result.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
| Structure and safety cage | Good |
| Passenger injury measures – Head/Neck | Good |
| Passenger injury measures – Chest | Good |
| Passenger injury measures – Hip/Thigh | Good |
| Passenger injury measures – Lower Leg/Foot | Good |
| Passenger restraints and dummy kinematics | Good |
Notably, all subcategories for passenger injury measures and restraints received “Good” ratings, indicating comprehensive protection for the front passenger in this challenging crash scenario.
Technical measurements for the passenger-side small overlap test are as follows:
Measures of occupant compartment intrusion (passenger side)
| Evaluation criteria | Measurement (cm) |
|---|---|
| Lower hinge pillar max | 6 |
| Footrest | 12 |
| Right toepan | 8 |
| Center toepan | 5 |
| Rocker panel lateral average | 3 |
| Center dash | 1 |
| Upper hinge pillar max | 5 |
| Upper dash | 4 |
| Right lower dash | 4 |
Passenger injury measures
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 109 |
| Neck Tension (kN) | 0.9 |
| Neck Extension bending moment (Nm) | 12 |
| Maximum Nij | 0.20 |
| Chest maximum compression (mm) | 25 |
| Femur Left (kN) | 0.2 |
| Femur Right (kN) | 0.0 |
| Knee displacement Left (mm) | 0 |
| Knee displacement Right (mm) | 0 |
| Knee-thigh-hip injury risk (%) Left | 0 |
| Knee-thigh-hip injury risk (%) Right | 0 |
| Maximum tibia index Left | 0.37 |
| Maximum tibia index Right | 0.60 |
| Tibia axial force Left (kN) | 1.8 |
| Tibia axial force Right (kN) | 1.7 |
| Foot acceleration Left (g) | 51 |
| Foot acceleration Right (g) | 77 |
Interestingly, driver-side measurements were also taken during the passenger-side test, all achieving “Good” ratings:
Driver injury measures (during passenger-side test)
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 68 |
| Neck Tension (kN) | 0.6 |
| Neck Extension bending moment (Nm) | 4 |
| Maximum Nij | 0.20 |
| Chest maximum compression (mm) | 20 |
| Femur Left (kN) | 0.3 |
| Femur Right (kN) | 0.7 |
| Knee displacement Left (mm) | 1 |
| Knee displacement Right (mm) | 1 |
| Knee-thigh-hip injury risk (%) Left | 0 |
| Knee-thigh-hip injury risk (%) Right | 0 |
| Maximum tibia index Left | 0.24 |
| Maximum tibia index Right | 0.26 |
| Tibia axial force Left (kN) | 0.6 |
| Tibia axial force Right (kN) | 2.4 |
| Foot acceleration Left (g) | 26 |
| Foot acceleration Right (g) | 62 |
Moderate Overlap Front Crash Test: Original Assessment
The moderate overlap front test is a more traditional frontal crash test, involving a larger portion of the vehicle’s front end impacting a deformable barrier. For the 2021 Mercedes-Benz C-Class (models 2015-21), the results are again reassuring.
The 2021 C-Class earned a “Good” overall rating in the moderate overlap front test.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
| Structure and safety cage | Good |
| Driver injury measures – Head/Neck | Good |
| Driver injury measures – Chest | Good |
| Driver injury measures – Leg/Foot, Left | Good |
| Driver injury measures – Leg/Foot, Right | Good |
| Driver restraints and dummy kinematics | Good |
All categories received “Good” ratings, indicating excellent protection in a frontal collision scenario.
Technical measurements for the moderate overlap front test are as follows:
Measures of occupant compartment intrusion (driver side)
| Evaluation criteria | Measurement (cm) |
|---|---|
| Footrest | 1 |
| Left footwell intrusion | 1 |
| Center footwell intrusion | 1 |
| Right footwell intrusion | 1 |
| Brake pedal intrusion | 2 |
| Instrument panel rearward movement Left | 0 |
| Instrument panel rearward movement Right | 0 |
| Steering column movement Upward | 3 |
| Steering column movement Rearward | -7 |
| A-pillar rearward movement | 0 |
Driver injury measures
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 148 |
| Peak gs at hard contact | 16 |
| Neck Tension (kN) | 1.1 |
| Neck Extension bending moment (Nm) | 11 |
| Maximum Nij | 0.20 |
| Chest maximum compression (mm) | 22 |
| Femur force – Left (kN) | 1.6 |
| Femur force – Right (kN) | 1.3 |
| Knee displacement – Left (mm) | 1 |
| Knee displacement – Right (mm) | 2 |
| Maximum tibia index – Left | 0.40 |
| Maximum tibia index – Right | 0.31 |
| Tibia axial force – Left (kN) | 2.3 |
| Tibia axial force – Right (kN) | 2.5 |
| Foot acceleration Left (g) | 36 |
| Foot acceleration Right (g) | 53 |
Side Impact Crash Test: Original Evaluation
The side impact test assesses how well a vehicle protects occupants in a side collision. The 2021 Mercedes-Benz C-Class, tested as a 2015 C 400 4-door 4wd model with standard airbags, again achieved the highest rating.
The 2021 C-Class earned an overall “Good” rating in the side impact test.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
| Structure and safety cage | Good |
| Driver injury measures – Head/Neck | Good |
| Driver injury measures – Torso | Good |
| Driver injury measures – Pelvis/Leg | Good |
| Driver head protection | Good |
| Rear passenger injury measures – Head/Neck | Good |
| Rear passenger injury measures – Torso | Good |
| Rear passenger injury measures – Pelvis/Leg | Good |
| Rear passenger head protection | Good |
Both driver and rear passenger injury measures and head protection categories received “Good” ratings, demonstrating excellent side impact protection.
Technical measurements for the side impact test are detailed below:
Measures of occupant compartment intrusion (driver side)
| Evaluation criteria | Measurement (cm) |
|---|---|
| B-pillar to longitudinal centerline of driver’s seat | -20.5 |
Driver injury measures
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 228 |
| Neck Tension (kN) | 1.0 |
| Neck Compression (kN) | 0.3 |
| Shoulder Lateral deflection (mm) | 40 |
| Shoulder Lateral force (kN) | 1.2 |
| Torso Maximum deflection (mm) | 35 |
| Torso Average deflection (mm) | 32 |
| Torso Maximum deflection rate (m/s) | 4.56 |
| Torso Maximum viscous criterion (m/s) | 0.51 |
| Pelvis Iliac force (kN) | 2.4 |
| Pelvis Acetabulum force (kN) | 1.2 |
| Pelvis Combined force (kN) | 3.6 |
| Left femur L-M force (kN) | 0.4 |
| Left femur L-M moment (Nm) | 36 |
| Left femur A-P moment (Nm) | 74 |
Passenger injury measures
| Evaluation criteria | Measurement |
|---|---|
| Head HIC-15 | 225 |
| Neck Tension (kN) | 0.7 |
| Neck Compression (kN) | 0.1 |
| Shoulder Lateral deflection (mm) | 34 |
| Shoulder Lateral force (kN) | 1.1 |
| Torso Maximum deflection (mm) | 22 |
| Torso Average deflection (mm) | 18 |
| Torso Maximum deflection rate (m/s) | 1.94 |
| Torso Maximum viscous criterion (m/s) | 0.19 |
| Pelvis Iliac force (kN) | 2.4 |
| Pelvis Acetabulum force (kN) | 2.0 |
| Pelvis Combined force (kN) | 4.2 |
| Left femur L-M force (kN) | 0.5 |
| Left femur L-M moment (Nm) | 33 |
| Left femur A-P moment (Nm) | 51 |
Roof Strength Evaluation
Roof strength is crucial in rollover accidents. The 2021 Mercedes-Benz C-Class demonstrates robust roof integrity.
The 2021 C-Class achieved a “Good” rating for roof strength. With a strength-to-weight ratio of 7.00, the roof can withstand over 7 times the vehicle’s weight.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
| Curb weight (lbs) | 3,522 |
| Peak force (lbs) | 24,642 |
| Strength-to-weight ratio | 7.00 |
Head Restraints and Seats: Whiplash Protection
Whiplash is a common injury in rear-end collisions. The 2021 Mercedes-Benz C-Class seats and head restraints are designed to mitigate this risk.
The 2021 C-Class earned a “Good” rating for head restraints and seats, both dynamically and geometrically.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
| Dynamic rating | Good |
| Seat/head restraint geometry | Good |
Technical measurements for the head restraints and seats are as follows:
| Seat type | Power leather seat |
|---|---|
| Backset (mm) | 38 |
| Distance below top of head (mm) | -14 |
| Max T1 acceleration (g) | 16.1 |
| Head contact time (ms) | 57 |
| Force rating | 1 |
| Max neck shear force (N) | 21 |
| Max neck tension (N) | 464 |
Headlight Performance: A Detailed Look
Headlight performance is vital for nighttime safety. The 2021 Mercedes-Benz C-Class offers various headlight configurations with different ratings.
Trim level: All trims with Exterior Lighting package; built after January 2021
These LED projector headlights with curve-adaptive functionality and high-beam assist achieve a “Good” rating overall.
| Evaluation criteria | Rating |
|---|---|
| Overall rating | Good |
| Low-beam headlight type | LED projector |
| High-beam headlight type | LED projector |
| Curve-adaptive? | Yes |
| High-beam assist? | Yes |
Trim level: C300 trim with Adaptive High Beam Assist package
These LED reflector headlights with high-beam assist also achieve a “Good” overall rating.
| Evaluation criteria | Rating |
|---|---|
| Overall rating | Good |
| Low-beam headlight type | LED reflector |
| High-beam headlight type | LED reflector |
| Curve-adaptive? | No |
| High-beam assist? | Yes |
Trim level: C300 trim (Standard Headlights)
The standard LED reflector headlights on the C300 trim receive an “Acceptable” rating.
| Evaluation criteria | Rating |
|---|---|
| Overall rating | Acceptable |
| Low-beam headlight type | LED reflector |
| High-beam headlight type | LED reflector |
| Curve-adaptive? | No |
| High-beam assist? | No |
Trim level: All trims with Exterior Lighting package; built before February 2021
Earlier models with the Exterior Lighting package, featuring LED projector headlights, received a “Marginal” rating due to excessive glare, highlighting improvements made in later production.
| Evaluation criteria | Rating |
|---|---|
| Overall rating | Marginal |
| Low-beam headlight type | LED projector |
| High-beam headlight type | LED projector |
| Curve-adaptive? | Yes |
| High-beam assist? | Yes |
Front Crash Prevention: Vehicle-to-Vehicle and Pedestrian
Crash prevention technology is increasingly important. The 2021 Mercedes-Benz C-Class offers advanced systems for vehicle-to-vehicle and pedestrian collision avoidance.
Vehicle-to-Vehicle Front Crash Prevention
With both standard “Active Brake Assist” and optional “Active Brake Assist with Cross-Traffic Function” (part of the Driver Assistance Package), the 2021 C-Class achieves a “Superior” rating in vehicle-to-vehicle front crash prevention. Both systems successfully avoided collisions in 12 mph and 25 mph tests.
Pedestrian Front Crash Prevention (Daytime)
The pedestrian front crash prevention system varies in performance:
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Optional Active Brake Assist with Cross-Traffic Function: “Superior” rating. Avoided collisions in crossing child and adult scenarios at both 12 mph and 25 mph. Showed significant speed reduction in parallel adult scenarios.
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Standard Active Brake Assist: “Basic” rating. Showed speed reduction in crossing child and adult scenarios but failed to slow sufficiently in parallel adult scenarios.
Child Seat Anchors (LATCH)
For families, child seat anchor ease of use is critical. The 2021 Mercedes-Benz C-Class LATCH system is rated for ease of use.
The 2021 C-Class LATCH system achieves a “Good” rating overall. It has two rear seating positions with complete LATCH hardware and an additional position with a tether anchor.
| Evaluation criteria | Rating |
|---|---|
| Overall evaluation | Good |
Child Seat Anchor Details by Position:
| Position | Rating | Details |
|---|---|---|
| 1 | Good | Tether & Lower Anchors: Easy to find, not too deep, easy to maneuver. |
| 2 | Not Rated | Tether Anchor Only: Easy to find. No lower anchors available. |
| 3 | Good | Tether & Lower Anchors: Easy to find, not too deep, easy to maneuver. |
Conclusion: 2021 Mercedes-Benz C-Class Safety Performance
The 2021 Mercedes-Benz C-Class demonstrates a strong commitment to safety, achieving top “Good” ratings in most IIHS crash tests. While there’s room for improvement in specific areas like headlight glare in earlier models and driver restraints in small overlap tests, the C-Class offers robust occupant protection. UK buyers looking for a safe and luxurious vehicle will find the 2021 Mercedes-Benz C-Class to be a compelling option, particularly when equipped with optional safety and lighting packages. Understanding these safety ratings provides valuable insight for making informed decisions when choosing a vehicle prioritising safety.
