The 2021 Nissan Sentra marked a significant redesign for the popular compact sedan, bringing with it updated styling, features, and most importantly, enhanced safety technology. As a content creator for cardiagxpert.com and an auto repair specialist, I’ve delved into the safety ratings of the 2021 Sentra to provide you with an expert analysis based on the Insurance Institute for Highway Safety (IIHS) data. This comprehensive breakdown will cover everything from crash test performance to headlight effectiveness and front crash prevention systems, helping you make an informed decision about the safety of the 2021 Sentra.
In-Depth Look at 2021 Sentra Crashworthiness
The IIHS, a leading authority in vehicle safety, conducts rigorous crash tests to evaluate how well vehicles protect occupants in various collision scenarios. The 2021 Nissan Sentra underwent several of these tests, and we’ll examine the results in detail.
Small Overlap Front: Driver-Side
The small overlap front crash test simulates a collision where only a small portion of the vehicle’s front end hits a rigid object, like a tree or pole. This is a particularly challenging test as it concentrates crash forces on a smaller area, bypassing some of the vehicle’s main energy-absorbing structures.
The 2021 Nissan Sentra received a Good rating in the driver-side small overlap front test. This is the highest rating possible and indicates that the vehicle provided excellent protection in this type of crash.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Structure and Safety Cage | G |
| Driver Injury Measures | |
| Head/Neck | G |
| Chest | G |
| Hip/Thigh | G |
| Lower Leg/Foot | G |
| Driver Restraints & Kinematics | G |
The technical measurements from the test further support this “Good” rating. Key metrics like occupant compartment intrusion were minimal, and driver injury measures were all within the “Good” range.
Technical Measurements – Driver-Side Small Overlap Front
| Measurement | Value |
|---|---|
| Lower Occupant Compartment Intrusion | |
| Lower hinge pillar max (cm) | 12 |
| Footrest (cm) | 18 |
| Left toepan (cm) | 7 |
| Brake pedal (cm) | 6 |
| Parking brake (cm) | 11 |
| Rocker panel lateral average (cm) | 2 |
| Upper Occupant Compartment Intrusion | |
| Steering column | 0 |
| Upper hinge pillar max (cm) | 4 |
| Upper dash (cm) | 7 |
| Lower instrument panel (cm) | 8 |
| Driver Injury Measures | |
| Head HIC-15 | 89 |
| Neck Tension (kN) | 1.2 |
| Neck Extension bending moment (Nm) | 9 |
| Chest maximum compression (mm) | 37 |
| Femur – Left (kN) | 1.5 |
| Femur – Right (kN) | 0.7 |
| Tibia Index – Left | 0.60 |
| Tibia Index – Right | 0.35 |
This strong performance in the driver-side small overlap test is a testament to the robust structural design of the 2021 Sentra, ensuring driver safety in a challenging frontal collision scenario.
Small Overlap Front: Passenger-Side
The passenger-side small overlap test is the counterpart to the driver-side test, evaluating protection for the front passenger. While structurally similar, the passenger side of a vehicle can sometimes perform differently in these tests.
The 2021 Nissan Sentra also achieved a Good overall rating in the passenger-side small overlap front test. However, the structure and safety cage received an Acceptable rating, a slight step down from “Good.” Despite this, all passenger and driver injury measures were rated as “Good.”
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Structure and Safety Cage | A |
| Passenger Injury Measures | |
| Head/Neck | G |
| Chest | G |
| Hip/Thigh | G |
| Lower Leg/Foot | G |
| Passenger Restraints & Kinematics | G |
| Driver Injury Measures | |
| Head/Neck | G |
| Chest | G |
| Hip/Thigh | G |
| Lower Leg/Foot | G |
| Driver Restraints & Kinematics | G |
Looking at the technical measurements, we can see slightly higher intrusion values on the passenger side compared to the driver side, which explains the “Acceptable” rating for the structure.
Technical Measurements – Passenger-Side Small Overlap Front
| Measurement | Value |
|---|---|
| Lower Occupant Compartment Intrusion | |
| Lower hinge pillar max (cm) | 17 |
| Footrest (cm) | 13 |
| Right toepan (cm) | 9 |
| Center toepan (cm) | 5 |
| Rocker panel lateral average (cm) | 0 |
| Upper Occupant Compartment Intrusion | |
| Center dash (cm) | 7 |
| Upper hinge pillar max (cm) | 7 |
| Upper dash (cm) | 10 |
| Right lower dash (cm) | 9 |
| Passenger Injury Measures | |
| Head HIC-15 | 282 |
| Neck Tension (kN) | 1.4 |
| Neck Extension bending moment (Nm) | 31 |
| Chest maximum compression (mm) | 18 |
| Femur – Left (kN) | 1.4 |
| Femur – Right (kN) | 2.4 |
| Tibia Index – Left | 0.60 |
| Tibia Index – Right | 0.46 |
| Driver Injury Measures | |
| Head HIC-15 | 97 |
| Neck Tension (kN) | 1.0 |
| Neck Extension bending moment (Nm) | 11 |
| Chest maximum compression (mm) | 32 |
| Femur – Left (kN) | 0.4 |
| Femur – Right (kN) | 0.7 |
| Tibia Index – Left | 0.21 |
| Tibia Index – Right | 0.33 |
Despite the “Acceptable” structure rating, the “Good” ratings for injury measures for both driver and passenger indicate a high level of protection in a passenger-side small overlap frontal crash for the 2021 Sentra.
Moderate Overlap Front: Original Test
The moderate overlap front test involves a larger portion of the vehicle’s front hitting a deformable barrier. This test is more traditional and represents a significant portion of real-world frontal collisions.
The 2021 Sentra earned a Good overall rating in the moderate overlap front test, mirroring its strong performance in other frontal crash tests. The structure and safety cage again received a “Good” rating. However, the driver injury measure for head/neck received an Acceptable rating, while all other injury measures were “Good.”
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Structure and Safety Cage | G |
| Driver Injury Measures | |
| Head/Neck | A |
| Chest | G |
| Leg/Foot, Left | G |
| Leg/Foot, Right | G |
| Driver Restraints & Kinematics | G |
Technical Measurements – Moderate Overlap Front
| Measurement | Value |
|---|---|
| Footwell Intrusion | |
| Footrest (cm) | 3 |
| Left (cm) | 9 |
| Center (cm) | 6 |
| Right (cm) | 4 |
| Brake pedal (cm) | 3 |
| Instrument Panel Rearward Movement | |
| Left (cm) | 2 |
| Right (cm) | 3 |
| Steering Column Movement | |
| Upward (cm) | 1 |
| Rearward (cm) | -2 |
| A-pillar Rearward Movement (cm) | 0 |
| Driver Injury Measures | |
| Head HIC-15 | 296 |
| Neck Tension (kN) | 1.1 |
| Neck Extension bending moment (Nm) | 12 |
| Chest maximum compression (mm) | 36 |
| Femur Force – Left (kN) | 1.0 |
| Femur Force – Right (kN) | 1.1 |
| Tibia Index – Left | 0.46 |
| Tibia Index – Right | 0.49 |
The “Acceptable” rating for head/neck injury risk in the moderate overlap test suggests a slightly elevated risk compared to other areas, but overall, the 2021 Sentra demonstrates robust frontal crash protection.
Side Impact: Original and Updated Tests
Side impacts are a significant concern in vehicle safety, and the IIHS conducts both original and updated side impact tests. The updated test is more demanding, using a heavier barrier and higher impact speed to better represent modern SUVs and trucks.
Side: Original Test
In the original side impact test, the 2021 Sentra achieved a Good overall rating, with “Good” ratings across all evaluation criteria for both driver and rear passenger injury measures, as well as structure and safety cage and head protection.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Structure and Safety Cage | G |
| Driver Injury Measures | |
| Head/Neck | G |
| Torso | G |
| Pelvis/Leg | G |
| Driver Head Protection | G |
| Rear Passenger Injury Measures | |
| Head/Neck | G |
| Torso | G |
| Pelvis/Leg | G |
| Rear Passenger Head Protection | G |
This “Good” performance in the original side impact test highlights the 2021 Sentra’s effective side structure and airbag system in protecting occupants during a perpendicular collision.
Side: Updated Test
However, in the more rigorous updated side impact test, the 2021 Sentra’s rating decreased to Acceptable overall. While structure and safety cage remained “Acceptable,” driver injury measures for torso and pelvis were also “Acceptable.” Critically, driver head protection was rated Marginal because the dummy’s head moved past the side curtain airbag and struck the window sill. Rear passenger protection remained “Good” across all measures.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | A |
| Structure and Safety Cage | A |
| Driver Injury Measures | |
| Head/Neck | G |
| Torso | A |
| Pelvis | A |
| Driver Head Protection | M |
| Rear Passenger Injury Measures | |
| Head/Neck | G |
| Torso | G |
| Pelvis | G |
| Rear Passenger Head Protection | G |
The images from the updated side crash test clearly illustrate the issue with driver head protection. The greasepaint on the window sill confirms head contact, leading to the “Marginal” rating. While rear passenger protection is still strong, this updated test reveals a vulnerability in driver-side protection in more severe side impacts.
Roof Strength
Roof strength is crucial in rollover crashes. The IIHS roof strength test measures how much force a roof can withstand before collapsing a certain amount.
The 2021 Nissan Sentra earned a Good rating for roof strength, with a strength-to-weight ratio of 4.70. This means the roof can withstand 4.7 times the vehicle’s weight before significant crush, indicating good rollover protection.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Curb Weight | 3,035 lbs |
| Peak Force | 14,266 lbs |
| Strength-to-Weight Ratio | 4.70 |
This “Good” rating provides reassurance that the 2021 Sentra’s roof structure is designed to offer solid protection in rollover scenarios.
Head Restraints & Seats
Whiplash is a common injury in rear-end collisions. The IIHS evaluates head restraints and seats to see how well they protect against whiplash in such crashes.
The 2021 Sentra received a Good overall rating for head restraints and seats, both for dynamic rating and seat/head restraint geometry.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G |
| Dynamic Rating | G |
| Seat/Head Restraint Geometry | G |
This “Good” rating in head restraints and seats indicates that the 2021 Sentra’s seating design effectively minimizes whiplash risk in rear-end collisions.
2021 Sentra Headlight Performance
Headlight effectiveness is a critical safety feature often overlooked. The IIHS evaluates headlights based on visibility and glare in various driving scenarios. The 2021 Sentra has three different headlight variations depending on trim level.
SR Trim with Premium Package: LED Projector Headlights – Acceptable
The SR trim with the Premium package features LED projector headlights and high-beam assist. These headlights earned an Acceptable overall rating. Low beam visibility was good on straightaways and right curves, but only fair on left curves. High beams were better, with good visibility on straightaways and gradual curves, but only fair on sharp curves. Glare was noted as “Some” for low beams.
| Evaluation Criteria | Rating |
|---|---|
| Overall Rating | A |
| Low-Beam Headlight Type | LED projector |
| High-Beam Headlight Type | LED projector |
| Curve-Adaptive? | No |
| High-Beam Assist? | Yes |
SR Trim: LED Reflector Headlights – Poor
The SR trim with standard LED reflector headlights received a Poor overall rating. Low beam visibility was inadequate across all scenarios. High beams were only fair on straightaways and inadequate on curves. Glare was not an issue with these headlights.
| Evaluation Criteria | Rating |
|---|---|
| Overall Rating | P |
| Low-Beam Headlight Type | LED reflector |
| High-Beam Headlight Type | LED reflector |
| Curve-Adaptive? | No |
| High-Beam Assist? | Yes |
S and SV Trims: Halogen Projector Headlights – Poor
The S and SV trims with halogen projector headlights also received a Poor overall rating. Similar to the LED reflector headlights, low beam and high beam visibility was generally inadequate across straightaways and curves. Glare was also not an issue with these halogen headlights.
| Evaluation Criteria | Rating |
|---|---|
| Overall Rating | P |
| Low-Beam Headlight Type | Halogen projector |
| High-Beam Headlight Type | Halogen projector |
| Curve-Adaptive? | No |
| High-Beam Assist? | Yes |
The headlight ratings highlight a significant variation in performance depending on the 2021 Sentra trim level. The LED projector headlights in the SR trim with Premium Package are “Acceptable,” while the other headlight options are rated “Poor,” suggesting potential nighttime visibility issues for those trims.
Front Crash Prevention: Vehicle-to-Vehicle & Pedestrian
Front crash prevention systems are increasingly important in modern vehicles. The IIHS tests two types of front crash prevention: vehicle-to-vehicle and pedestrian.
Vehicle-to-Vehicle Front Crash Prevention – Superior
The 2021 Nissan Sentra’s standard automatic emergency braking system with pedestrian detection earned a Superior rating for vehicle-to-vehicle front crash prevention. The system avoided collisions in both 12 mph and 25 mph tests and meets forward collision warning requirements.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | Superior |
| Forward Collision Warning | Meets requirements |
| 12 mph Test Performance | Collision Avoided |
| 25 mph Test Performance | Collision Avoided |
This “Superior” rating demonstrates the effectiveness of the 2021 Sentra’s automatic emergency braking system in preventing or mitigating vehicle-to-vehicle frontal collisions.
Pedestrian Front Crash Prevention (Day) – Advanced
For pedestrian front crash prevention (daytime), the 2021 Sentra’s system received an Advanced rating. It avoided collisions in the 12 mph crossing adult and child tests. In the 25 mph crossing child test, impact speed was reduced, and in the parallel adult tests, collisions were avoided or impact speed significantly reduced.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | Advanced |
| Crossing Child (12 mph) | Collision Avoided |
| Crossing Child (25 mph) | Speed Reduced |
| Crossing Adult (12 mph) | Collision Avoided |
| Crossing Adult (25 mph) | Collision Avoided |
| Parallel Adult (25 mph) | Collision Avoided |
| Parallel Adult (37 mph) | Speed Reduced |
The “Advanced” rating for pedestrian front crash prevention highlights the 2021 Sentra’s capability in detecting and reacting to pedestrians in daytime conditions, further enhancing safety for vulnerable road users.
Child Seat Anchors (LATCH)
Child seat anchors (LATCH) ease the installation of child safety seats. The IIHS evaluates the usability of LATCH systems.
The 2021 Sentra received a Good + Extra LATCH positions rating, the highest possible. It has two rear seating positions with complete LATCH hardware and an additional position with a tether anchor and ability to borrow lower anchors.
| Evaluation Criteria | Rating |
|---|---|
| Overall Evaluation | G + Extra LATCH positions |
| Number of LATCH positions | 2 complete, 1 additional |
This “Good+” rating for LATCH confirms that the 2021 Sentra is very child-seat friendly, offering versatile and easy-to-use anchor systems.
Conclusion: 2021 Nissan Sentra – A Safe Choice with Room for Improvement
Overall, the 2021 Nissan Sentra demonstrates a strong commitment to safety, earning mostly “Good” ratings in IIHS crash tests. It excels in frontal crash scenarios and offers “Superior” vehicle-to-vehicle front crash prevention and “Advanced” pedestrian front crash prevention. Child seat anchor usability is also top-notch.
However, the “Acceptable” rating in the updated side impact test and the “Poor” headlight ratings (except for the top trim’s optional headlights) reveal areas where the 2021 Sentra could be improved. Specifically, enhancing driver-side protection in severe side impacts and improving headlight performance across all trims would elevate the Sentra’s safety profile further.
For potential buyers of a 2021 Sentra, focusing on trims with the LED projector headlights (SR with Premium Package) is advisable for better nighttime visibility. Understanding the nuances of the updated side impact test is also important for making a fully informed safety assessment.
Despite these points for improvement, the 2021 Nissan Sentra remains a safe and well-regarded compact sedan, particularly for frontal crash protection and crash avoidance technology. As always, consider your specific needs and priorities when evaluating vehicle safety, and use this expert analysis to guide your decision-making process.
