Last updated: 2026-07-26
2021 Mercedes-Benz GLB Reliability Report
The 2021 Mercedes-Benz GLB scores 65/100 ("Good"). With 10 recalls and 30 owner complaints, reliability is acceptable but not class-leading.
Recalls
10
Complaints
30
Complaint Rate
11.2per 10,000 sold
Est. Repair Cost
$908
Annual Fuel Cost
$2,850
Detailed Score Breakdown
Component-weighted complaints normalized by sales volume
Independent repair cost ratings
Recall count weighted by severity
Breadth of reported problem categories
The Verdict
Acceptable reliability — worth considering with a pre-purchase inspection.
Top Issues to Watch
- ELECTRICAL SYSTEM (5)
- ENGINE (4)
- POWER TRAIN (3)
Generation & Refresh (US)
2021 is year 2 of the First generation (X247; 2019).
- Redesigned for the 2020 model year.
- A refresh arrives in 2024.
- 1st generation GLB (US).
What this means for buyers
Year 2 is typically a safer pick than the first model year — early issues are more likely to be identified, but the platform is still new.
If you're comparing prices, check 2020 (redesign year) vs 2021+ pricing and recalls.
2020: First generation (X247; 2019) Launch
Generation start — new platform.
2021: This Model Year
2021 is year 2 of the First generation (X247; 2019).
2024: Mid-Cycle Refresh
Updated features and styling tweaks.
Should You Buy the 2021 Mercedes-Benz GLB?
At 65/100, the 2021 Mercedes-Benz GLB lands in "Good" territory — acceptable, but not class-leading. 2021 is year 2 of the First generation (X247; 2019).
Owners log 30 complaints on this model year — enough to suggest attention is needed, but no single failure mode dominates yet.
Get a pre-purchase inspection on any used example, with extra attention to unknown or other (8). An extended warranty is worth pricing out.
Compared to the 2022 Mercedes-Benz GLB, which scored 10 points higher. See also the 2020 Mercedes-Benz GLB for an earlier comparison.
Pros
- +Acceptable reliability score
- +Below-average complaint rate for SUV
- +5-star NHTSA crash rating
Cons
- −Above-average recall count
- −UNKNOWN OR OTHER: Two primary issues with the 2021 Mercedes-Benz GLB: spontaneous sunroof... (8 complaints)
- −ELECTRICAL SYSTEM: Owners of the 2021 Mercedes-Benz GLB frequently report issues with the... (5 complaints)
Compare 2021 Mercedes-Benz GLB With
2021 Cadillac XT4
Reliability: 71/100
2021 Buick Envision
Reliability: 74/100
2021 Cadillac XT6
Reliability: 73/100
2021 Infiniti QX60
Reliability: 81/100
2021 Buick Encore GX
Reliability: 74/100
Common Problem Categories
Safety
LOW RISK- 10 manufacturer recalls issued
Other
HIGH RISK- UNKNOWN OR OTHER (8)
- ELECTRICAL SYSTEM (5)
Recall Overview
10
recalls on record
The 2021 Mercedes-Benz GLB has 10 recalls on record, which is above average. A high count can flag multiple component concerns, though it also shows the manufacturer is actively addressing known issues.
NHTSA.gov →Complaint Breakdown
11.2
per 10,000 soldSegment avg: 16.7
Safety Incidents
0
Crashes
0
Fires
0
Injuries
0
Deaths
NHTSA 5/5 Stars
Data sourced from NHTSA complaint filings and manufacturer recall notices. Complaint narratives are owner-reported.
2021 Mercedes-Benz GLB Recall Details
10 recalls have been issued for the 2021 Mercedes-Benz GLB. All recall repairs are performed free of charge at authorized dealerships.
STRUCTURE
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 GLB35 AMG, and 2020-2021 GLB250 vehicles. The side spoilers on the tailgate might not have been installed correctly, allowing them to detach.
Consequence
Detached spoilers can create a road hazard, increasing the risk of a crash or injury.
Remedy
MBUSA will notify owners, and dealers will inspect and, if necessary, replace the side spoilers, free of charge. Owner letters were mailed July 2, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021050009.
STRUCTURE
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2020-2021 GLB250 vehicles. The wheel arch covers on the front fenders might not have been installed correctly, allow them to detach.
Consequence
Detached wheel arch covers can create a road hazard, increasing the risk of a crash or injury.
Remedy
MBUSA will notify owners, and dealers will check the installation of the front wheel arch covers and correct them as necessary, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040015.
ELECTRONIC STABILITY CONTROL (ESC)
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 GLB250 vehicles. The Electronic Stability Program (ESP) unit may be damaged, which can result in disabled anti-lock brakes (ABS), disabled electronic stability control (ESC), and an electrical short circuit.
Consequence
Disabled anti-lock brakes and electronic stability control can increase the risk of a crash or injury. An electrical short circuit increases the risk of a fire.
Remedy
Dealers will replace the ESP unit, free of charge. Owner notification letters were mailed October 28, 2022. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2022090009.
Buying a used 2021 Mercedes-Benz GLB? Check its history first
Every 2021 Mercedes-Benz GLB has a different past. A VIN check reveals hidden accidents, title problems, odometer rollbacks, and open recalls that reliability scores can't show you.
- Accidents
- Open Recalls
- Title History
- Odometer Rollback
2021 Mercedes-Benz GLB NHTSA Safety Ratings
Overall Safety Rating
Crash Test Results by Configuration (expand)
Gas Powertrain
Rollover risk: 15.9%
Safety Technologies
Mercedes-Benz GLBRepair Costs & Maintenance
Maintenance Rating
3Maintenance rating: 3 out of 5Based on NHTSA complaint patterns, recall severity, and publicly available cost benchmarks.
Est. Annual Maintenance
$908
Category-level averages derived from publicly available industry reports (AAA, CarMD). Model-level estimates produced by Auto Reliability Index.
MPG & Annual Running Costs
Gas
26 MPG
Running cost: $3,750/yr
Fuel + repair
23 city / 30–31 hwy MPG
Running cost includes EPA fuel-cost estimate and independent repair-cost data (repair cost estimated at model level). Excludes routine maintenance, depreciation, and insurance. Data as of 2021 EPA label cycle.
Gas trims
| Trim | Drive | Trans. | City | Hwy | Comb | Fuel Cost |
|---|---|---|---|---|---|---|
| GLB250 2.0L 4-cyl | Front-Wheel Drive | Automatic (AM8) | 23 | 31 | 26 | $2,850 |
| GLB250 4matic 2.0L 4-cyl | 4-Wheel Drive | Automatic (AM8) | 23 | 30 | 26 | $2,850 |
Used Buying Checklist
Key things to inspect or verify before purchasing a 2021 Mercedes-Benz GLB.
Inspect engine for signs of shaking or rough idling
Check for metal particles in engine oil
Test sunroof for any unusual sounds or signs of stress
Verify transmission shifts smoothly without clunking noises
Ensure electrical system is fully functional, especially dashboard and warning lights
Confirm suspension components are intact and free of unusual noises
Check for any unresolved recall repairs
2021 Mercedes-Benz GLB Common Problems by Component
30 owner complaints grouped by vehicle system.
UNKNOWN OR OTHER
8 complaintsOwners report two primary issues with the 2021 Mercedes-Benz GLB: spontaneous sunroof shattering and engine performance problems. Multiple complaints describe the panoramic sunroof unexpectedly exploding, resulting in glass falling into the vehicle, with incidents occurring while driving at highway speeds. Additionally, several owners mention engine issues, including jerking, rough idling, and loss of power, with some reports indicating metal particles in the oil and the need for engine replacement. These problems often manifest around 29,000 miles, posing potential safety risks such as loss of control and possible injury from shattered glass. Buyers should be aware of these reported issues when considering this model.
ELECTRICAL SYSTEM
5 complaintsOwners of the 2021 Mercedes-Benz GLB frequently report issues with the vehicle's electrical system. Common symptoms include the horn randomly honking while driving, potentially causing confusion and safety risks. Some owners experience complete electrical system failures while driving, leading to a non-functional dashboard and uncertainty about the vehicle's safety. Reports also mention a transmission malfunction warning light triggering a limp mode at highway speeds, with ongoing software development to address this issue. Additionally, there are complaints about delays in recall repairs related to electrical system components, although some owners have not experienced failures. These issues often occur at varying mileages, and the safety implications include potential loss of vehicle control and increased risk during highway driving.
ENGINE
4 complaintsOwners report several engine-related issues with the 2021 Mercedes-Benz GLB, including catastrophic engine failure and cylinder head problems. Complaints frequently mention symptoms such as engine shaking, loss of power, excessive noise, and engine lights turning on. These issues appear to occur at mileage as low as 35,000 miles, with some owners experiencing complete engine replacements. Safety implications are noted, as one owner describes losing power on the interstate, leading to a challenging and potentially dangerous situation to maneuver the vehicle to safety. Potential buyers should be aware of these issues and the associated repair costs, as well as the reported difficulties in obtaining satisfactory resolutions from dealerships and the manufacturer.
POWER TRAIN (3 complaints)
POWER TRAIN
3 complaintsOwners of the 2021 Mercedes-Benz GLB report issues related to the power train, with two primary concerns emerging. Multiple complaints describe a loud clunking noise from the transmission during downshifts, particularly from D4 to D1, which occurs when the vehicle comes to a stop. This issue is reported soon after purchase, even in certified used vehicles. Additionally, a complaint highlights a severe engine problem involving cylinder head failure and subsequent engine seizure, leading to undriveable conditions and potential safety risks due to sudden power loss. These issues appear in vehicles with varied mileage, including one at 81,000 miles, and may suggest underlying mechanical defects.
STEERING (2 complaints)
STEERING
2 complaintsOwners of the 2021 Mercedes-Benz GLB report issues related to the steering and front axle components, with common symptoms including a persistent pull to the left and loud clunking or cracking noises from the front axle, especially at low speeds. Complaints frequently mention that these problems arise after repairs or appear suddenly, with one owner noting persistent issues post-suspension and mount repairs. The steering pull requires constant correction to prevent unintended lane departure, posing potential safety risks. These issues seem to affect the vehicle regardless of mileage, and multiple owners suggest that the problems are widespread among this model and year, indicating a need for thorough inspection when considering a used purchase.
SUSPENSION (2 complaints)
SUSPENSION
2 complaintsOwners of the 2021 Mercedes-Benz GLB report issues related to the suspension, specifically involving the front right ball joint and control arm. One complaint describes the front right ball joint separating from the lower control arm, leading to a disconnected drive shaft and rendering the vehicle non-drivable at approximately 15 mph. Another owner reports a loud "clunk" noise from the undercarriage and sensations of tire slipping, particularly during slow-speed U-turns, which the dealership attributed to the vehicle being equipped with summer tires unsuitable for winter conditions. These issues arise at low mileage, around 3,000 miles, and present potential safety concerns, including the risk of collision due to sudden mechanical failure or loss of traction.
VISIBILITY (1 complaints)
VISIBILITY
1 complaintThe contact owns a 2021 Mercedes-Benz GLB250. The contact stated that the vehicle was parked in the garage; however, after driving out of the garage, the contact became aware of a crack on the windshield from the rear-view mirror ten inches downward. The contact stated that the crack seemed to be on the inside over the sensors. The vehicle had not yet been diagnosed or repaired. The dealer nor manufacturer was notified of the failure. The failure mileage was 13,716.
VISIBILITY/WIPER (1 complaints)
VISIBILITY/WIPER
1 complaintDriving on north bound of Merritt Parkway between exit 17 and 18. Today 12/10/25 9:28 AM My panoramic sunroof exploded ! all catch on video, driver on the vehicle behind me , came to check on me; and told me the glass went over four feet up in the air and then hit his vehicle windshield, I call Mercedes Benz customer service support to report the incident and open a case, they told me to drive to the closest dealer from the incident (Mercedes Benz of Fairfield) when I arrived and show the vehicle to the technician, he was trying to tell me that was my fault and he never heard such a thing of a sunroof explosion… and was looking for a reason to blame me, I told him I got all on video due to I have a dash camera that records the our side and the inside of the vehicle.. the outside temperature was 30 degrees Fahrenheit, and the inside temperature in the vehicle was set to 69 degrees… My speed was 55 to 56 miles per hour. Light to moderate traffic, the explosion sound like a gunshot, that was my first impression, some one shoot at me… The dealer, told me that I should call my insurance or Mercedes Benz and the only think they can do, is to tell me how much will cost to repair the damage.. and that they will park my car on a different building so don’t get rain on it, until I decided what I want to do.
SEAT BELTS (1 complaints)
SEAT BELTS
1 complaintSeat belt failure.Driver side…mechanism… it feels unsafe…the retractor is not locking
TIRES (1 complaints)
TIRES
1 complaintThe contact owns a 2021 Mercedes-Benz GLB250 equipped with Continental Tires, Tire Line: ProContact GX SSR, Tire Line: 235/55/R18, DOT Number: A33LWXX41220. The contact stated while driving 70 MPH, the vehicle began to vibrate with a flapping sound coming from the vehicle. Despite the failure, the contact was able to drive the vehicle to the residence. The contact then drove the vehicle to an independent mechanic where three humps were discovered on the front driver’s side tire that had formed due to thread separation on the inside of the tire. The mechanic referred the contact to a dealer who then referred the contact to the Continental tire manufacturer. The manufacturer informed the contact that the tire should be sent to the headquarters for an inspection. The tire was replaced. The failure mileage was approximately 30,600.
When Do 2021 Mercedes-Benz GLB Problems Start?
Based on owner complaint patterns, here's when common issues tend to appear.
Best & Worst Mercedes-Benz GLB Years
Comprehensive reliability analysis based on NHTSA data, owner complaints, and historical performance.
Best Mercedes-Benz GLB Years to Buy
Based on reliability index scoreThe best Mercedes-Benz GLB year is 2022 with a reliability score of 75/100, rated good. Other strong picks include 2023 (74/100) and 2024 (72/100).
Mercedes-Benz GLB Years to Avoid
The worst Mercedes-Benz GLB year is 2020 with a score of 59/100, primarily due to structure (13) issues.
Mercedes-Benz GLB Reliability Score Trend
Mercedes-Benz GLB reliability has improved in recent years, with newer models scoring an average of 74/100 compared to 62/100 for older years.
Scores 0–100. Higher is better. Current year highlighted.
| Year | Score | Rating |
|---|---|---|
| 2020 | 59/100 | Mixed |
| 2021 | 65/100 | Good |
| 2022 | 75/100 | Good |
| 2023 | 74/100 | Good |
| 2024 | 72/100 | Good |
Mercedes-Benz GLB Reliability Compared to Other Years
Frequently Asked Questions
Is the 2021 Mercedes-Benz GLB reliable?
What are the most common problems with the 2021 Mercedes-Benz GLB?
How many recalls does the 2021 Mercedes-Benz GLB have?
Is the 2021 Mercedes-Benz GLB expensive to maintain?
Don’t buy a 2021 Mercedes-Benz GLB without checking its VIN first — hidden accidents, title issues, and open recalls could cost you thousands.
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How We Calculate Reliability Scores
Auto Reliability Index scores are calculated on a 0–100 scale using a weighted formula that combines multiple public data sources. Each factor is weighted based on its predictive value for real-world ownership experience.
Key Ranking Factors
Complaint Severity
NHTSA owner complaints weighted by component category (e.g., powertrain, safety systems, electronics, cosmetic) — safety-critical issues carry more weight than cosmetic ones. Adjusted for sales volume so high-volume models aren't unfairly penalized.
Repair Costs
Independent reliability ratings based on repair frequency, average repair costs, and severity of typical repairs for each model.
Recall Impact
Number of NHTSA recalls weighted by severity. “Stop driving” and fire-risk recalls are penalized more heavily than minor software or labeling recalls.
Issue Diversity
Measures how many major vehicle systems (engine, transmission, electrical, braking, etc.) have recorded complaints. A vehicle with issues spread across many systems may indicate systemic quality issues.
Scores are grouped into four tiers:
- 80–100: Excellent— Top-tier reliability, minimal issues
- 60–79: Good— Reliable with some minor concerns
- 40–59: Mixed— Notable issues, research before buying
- 0–39: Risky— Significant problems, proceed with caution
Data is sourced from NHTSA recall records, owner complaint filings, and independent repair databases. Scores are recalculated as new data becomes available. While the weighting model is proprietary, all underlying data sources are public and traceable.
Get notified when new recalls or reliability data is added for the Mercedes-Benz GLB.
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