Last updated: 2026-07-25

2021 Mazda CX-9 Reliability Report
The 2021 Mazda CX-9 scores 77/100 ("Good"). With 1 recall and 35 owner complaints, reliability is acceptable but not class-leading.
Recalls
1
Complaints
35
Complaint Rate
10.1per 10,000 sold
Est. Repair Cost
$539
Annual Fuel Cost
$2,500–$2,600
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
- ENGINE (17)
- POWER TRAIN (2)
- SERVICE BRAKES (2)
Generation & Refresh (US)
2021 is year 6 of the Second generation (TC; 2016).
- Redesigned for the 2016 model year.
- Well-established in its generation — most early issues should be resolved.
- 2nd generation CX-9 (US).
What this means for buyers
Well into the generation cycle — most design and manufacturing issues should be resolved by now.
2016: Second generation (TC; 2016) Launch
Generation start — new platform.
2021: This Model Year
2021 is year 6 of the Second generation (TC; 2016).
Should You Buy the 2021 Mazda CX-9?
At 77/100, the 2021 Mazda CX-9 lands in "Good" territory — acceptable, but not class-leading. 2021 is year 6 of the Second generation (TC; 2016).
Owners log 35 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 engine (17). An extended warranty is worth pricing out.
Compared to the 2022 Mazda CX-9, which scored 4 points higher. See also the 2020 Mazda CX-9 for an earlier comparison.
Pros
- +Acceptable reliability score
- +$245 cheaper to maintain than avg midsize SUV
- +Low major repair risk (10%)
- +Low recall count
Cons
- −ENGINE issues reported (17 complaints)
- −UNKNOWN OR OTHER: Owners of the 2021 Mazda CX-9 report several issues related to vehicle... (4 complaints)
Compare 2021 Mazda CX-9 With

2021 Toyota Highlander
Reliability: 70/100

2021 KIA Telluride
Reliability: 63/100

2021 Hyundai Palisade
Reliability: 61/100

2021 Honda Pilot
Reliability: 63/100

2021 Volkswagen Atlas
Reliability: 44/100
Common Problem Categories
Safety
LOW RISK- 1 manufacturer recall issued
Other
HIGH RISK- ENGINE (17)
- UNKNOWN OR OTHER (4)
Recall Overview
1
recall on record
The 2021 Mazda CX-9 carries 1 recall — a low count. Authorized dealers repair any open recall free of charge, regardless of warranty status.
NHTSA.gov →Complaint Breakdown
10.1
per 10,000 soldSegment avg: 16.7
Safety Incidents
6
Crashes
0
Fires
1
Injuries
0
Deaths
NHTSA 5/5 Stars
Data sourced from NHTSA complaint filings and manufacturer recall notices. Complaint narratives are owner-reported.
2021 Mazda CX-9 Recall Details
1 recall has been issued for the 2021 Mazda CX-9. All recall repairs are performed free of charge at authorized dealerships.
SEATS, SEAT BELTS
Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 210, "Seat Belt Assembly Anchorages."
Consequence
A seat that slides forward during a crash can transfer excessive force onto a belted occupant, increasing their risk of injury.
Remedy
Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 5221I.
Buying a used 2021 Mazda CX-9? Check its history first
Every 2021 Mazda CX-9 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 Mazda CX-9 NHTSA Safety Ratings
Overall Safety Rating
Crash Test Results by Configuration (expand)
Gas Powertrain
Rollover risk: 15.1%
Safety Technologies
Mazda CX-9Repair Costs & Maintenance
Maintenance Rating
4Maintenance rating: 4 out of 5Based on NHTSA complaint patterns, recall severity, and publicly available cost benchmarks.
Est. Annual Maintenance
$539
vs $784 avg for midsize SUV
vs $652 avg for all vehicles
Repair Frequency
0.6
unscheduled repair visits per year
Severe Repair Probability
10%
chance of a major repair
Annual Cost Comparison
Category-level averages derived from publicly available industry reports (AAA, CarMD). Model-level estimates produced by Auto Reliability Index.
MPG & Annual Running Costs
Gas
23–24 MPG
Running cost: $3,050–$3,150/yr
Fuel + repair
20–22 city / 26–28 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 |
|---|---|---|---|---|---|---|
| CX-9 2WD 2.5L 4-cyl | Front-Wheel Drive | Automatic (S6) | 22 | 28 | 24 | $2,500 |
| CX-9 4WD 2.5L 4-cyl | 4-Wheel Drive | Automatic (S6) | 20 | 26 | 23 | $2,600 |
Used Buying Checklist
Key things to inspect or verify before purchasing a 2021 Mazda CX-9.
Check for excessive oil consumption by inspecting oil level and checking for low oil warning lights
Verify completion of any valve stem seal repairs under the class action settlement
Inspect brakes for persistent clicking or squeaking noises, even after recent replacements
Test the airbag system functionality and inspect for any previous deployment issues
Ensure the vehicle does not exhibit unexpected acceleration or loss of power during test drives
2021 Mazda CX-9 Common Problems by Component
35 owner complaints grouped by vehicle system.
ENGINE
17 complaintsOwners report that the 2021 Mazda CX-9 frequently experiences excessive oil consumption, with many noting the need to add approximately one quart of oil every 2,500 to 3,500 miles. Complaints often mention the low oil warning light activating and the discovery of low oil levels upon inspection. Some owners attribute the issue to defective valve stem seals, as referenced in technical service bulletins and a class action lawsuit. The majority of these issues are reported around 10,000 to 50,000 miles. While no direct safety incidents such as crashes or fires are described, the potential for engine damage or failure due to oil loss is a concern for owners. This information is particularly relevant for used car buyers considering this model.
UNKNOWN OR OTHER
4 complaintsOwners of the 2021 Mazda CX-9 report several issues related to vehicle malfunction and unexpected behavior. Multiple complaints describe sudden vehicle stops due to malfunctions in systems such as i-ACTIVESENSE, Dynamic Stability Control, and the engine, with incidents occurring at least twice for one owner. Another owner reports excessive oil consumption beginning after the first oil change. Additionally, there are concerns about the vehicle's auto-locking feature, which can engage unexpectedly, potentially locking occupants or items inside without warning. These issues present potential safety risks, including the risk of collisions from sudden stops and the danger of being unable to access the vehicle in emergencies.
POWER TRAIN
2 complaintsSafety-relatedOwners of the 2021 Mazda CX-9 report issues related to the powertrain, specifically involving cylinder compression loss and unintended acceleration. One complaint involves a loss of compression in a cylinder, attributed to a valve stem seal issue, with the owner noting this occurred at approximately 60,083 miles. Another complaint describes the vehicle unexpectedly accelerating forward while in reverse, resulting in a crash that caused injury, with no prior warning indicators or brake assist activation. These reports highlight potential safety implications, including loss of vehicle control and injury risk, particularly in parking scenarios. Buyers should be aware of these issues, especially regarding the valve stem seal settlement and its coverage limitations.
SERVICE BRAKES (2 complaints)
SERVICE BRAKES
2 complaintsSafety-relatedOwners of the 2021 Mazda CX-9 report persistent issues with the service brakes. One complaint describes ongoing clicking and squeaking noises from the brakes, even after replacement of both front and rear brakes and rotors at around 22,000 miles, with the issue persisting up to 49,000 miles. Another report details a failure of the brakes to maintain pressure during a hard stop, leading to a crash when the brakes unexpectedly released. This incident also involved a failure of the driver's side airbag to deploy. The complaints highlight potential safety risks, including a crash due to brake malfunction, and suggest that these issues may persist despite dealer interventions.
AIR BAGS (2 complaints)
AIR BAGS
2 complaintsSafety-relatedOwners of the 2021 Mazda CX-9 report issues with airbag deployment in crash scenarios. One complaint describes a frontal collision at 10-20 mph where the driver-side airbag failed to deploy, rendering the vehicle undrivable post-collision. Another report highlights that during an airbag deployment, the right curtain airbag caused the rear passenger handle and hook to splinter into sharp projectiles, posing a risk to occupants. These incidents involve crashes, indicating potential safety implications with the airbag system. Such reports may be relevant for used car buyers considering the safety performance of the airbag system in this model.
BACK OVER PREVENTION (1 complaints)
BACK OVER PREVENTION
1 complaintSafety-relatedBackup camera shows three to four feet before red collision line is not accurate causing severe damage to my garage door.
FORWARD COLLISION AVOIDANCE (1 complaints)
FORWARD COLLISION AVOIDANCE
1 complaintOn [XXX], [XXX], [XXX] I was driving on an interstate highway with a 65 mph speed limit with no warning and received the following codes which slowed the vehicle to the limp mode. 1) Smart Brake Support and Forward Obstruction Warning 2) Activsense system malfunction 3) Front Radar Sensor Malfunction 4) Engine Malfunction 5) Dynamic Stability Control Malfunction I reported all three incidents to the dealer and no codes were left and the dealership had no solution for the problem. They suggested dirt, sunlight, or blowing debris caused it, but that was not the case. Luckily the first two incidents happened with little or no traffic around but the third was during rush hour and almost caused a major accident trying to get off the highway. I shut the car off, restarted and the problem resolved no lights left on or warnings appearing all three times. Contacted Mazda several times and all representatives at the dealership and California Headquarters claim no knowledge of this happening. I found a few others reporting the same issue and wanted to report this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
SUSPENSION (1 complaints)
SUSPENSION
1 complaintThe contact owns a 2021 Mazda CX-9. The contact stated while driving at various speeds and turning, there was a popping sound coming from the front end of the vehicle. The front-end popping sound also occurred while driving over bumps in the roadway. The vehicle was taken to an independent mechanic who was unable to determine the cause of the failure. The vehicle was not repaired. The local dealer and manufacturer were not notified of the failure. The failure mileage was 68,811.
VEHICLE SPEED CONTROL (1 complaints)
VEHICLE SPEED CONTROL
1 complaintThe contact owns a 2021 Mazda CX-9. The contact stated that while accelerating quickly and entering the highway, there was no motive power to the vehicle. While crossing the highway in the right lane, driving at 65 MPH, the vehicle in front moved over; there was a parked vehicle. The contact was able to stop the vehicle before causing a crash. The driver was starting to accelerate, but there was no motive power when the accelerator pedal was depressed. The smart brake system malfunction message was displayed. There were no warning lights illuminated. The contact called the local dealer, who scheduled an appointment. The vehicle was not diagnosed or repaired. The manufacturer was contacted and informed the contact to have the vehicle diagnosed. The failure mileage was approximately 53,186.
WHEELS (1 complaints)
WHEELS
1 complaintI was driving approximately 75-80 mph (speed limit for I-90 is 80 mph) on I-90 Eastbound in South Dakota (approximately 5-8 miles from Sioux Falls, SD) in the left-hand lane (passing lane with a minimal shoulder) when I heard a terrible noise that sounded like I had a flat tire and the car began to pull to the left. I immediately slowed down and steered the vehicle onto the small shoulder on the left-hand side of the interstate. It was at this point I looked out my window (driver's window) and saw the entire left front wheel (not just the rubber tire) rolling by (west in the grassy median of I-90). The vehicle did not roll over, hit another vehicle, or get hit by another vehicle. After coming to a safe stop, I got out of the vehicle and saw that the left front (driver's side) wheel (not just the rubber tire) was gone. There were two (2) other passengers in the vehicle at the time that the wheel fell off who exited the vehicle out of danger of passing cars/trucks/semi tractor trailers on I-90. The vehicle was towed and to my knowledge has not been inspected by the manufacturer. The Hertz rental vehicle was only "inspected" by PurCo claims specialist via pictures as they did not have the vehicle in their possession. There were no warning messages, lamps, lights, or other symptoms prior to the wheel falling off. The wheel fell off on 7/8/2023 on Interstate 90 in South Dakota. After the wheel fell off, it rolled down the median of I-90 bounced up onto the westbound lane of I-90 and struck another vehicle causing that vehicle's airbags to deploy. There were four (4) occupants in that vehicle.
When Do 2021 Mazda CX-9 Problems Start?
Based on owner complaint patterns, here's when common issues tend to appear.
Best & Worst Mazda CX-9 Years
Comprehensive reliability analysis based on NHTSA data, owner complaints, and historical performance.
Best Mazda CX-9 Years to Buy
Based on reliability index scoreThe best Mazda CX-9 year is 2023 with a reliability score of 81/100, rated excellent. Other strong picks include 2022 (81/100) and 2020 (78/100).
Mazda CX-9 Years to Avoid
The worst Mazda CX-9 year is 2018 with a score of 66/100, primarily due to engine (60) issues.
Mazda CX-9 Reliability Score Trend
Mazda CX-9 reliability has improved in recent years, with newer models scoring an average of 80/100 compared to 72/100 for older years.
Scores 0–100. Higher is better. Current year highlighted.
| Year | Score | Rating |
|---|---|---|
| 2018 | 66/100 | Good |
| 2019 | 73/100 | Good |
| 2020 | 78/100 | Good |
| 2021 | 77/100 | Good |
| 2022 | 81/100 | Excellent |
| 2023 | 81/100 | Excellent |
Mazda CX-9 Reliability Compared to Other Years
Frequently Asked Questions
Is the 2021 Mazda CX-9 reliable?
What are the most common problems with the 2021 Mazda CX-9?
How many recalls does the 2021 Mazda CX-9 have?
Is the 2021 Mazda CX-9 expensive to maintain?
Don’t buy a 2021 Mazda CX-9 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 Mazda CX-9.
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