Last updated: 2026-10-10

2021 Mazda CX-9 Reliability Report
The 2021 Mazda CX-9 has good reliability, well above most 2021 SUVs, but owners report burning oil, often a quart every 2,500 to 4,000 miles.
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
Rated good and in the middle of the CX-9 years, with oil burning as the main complaint and one recall covering seats and seat belts.
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?
Good, and well above average among 2021 SUVs. Within the CX-9 lineup, this year sits in the middle of six scored years. It earned 5 of 5 stars in federal crash testing, and independent repair-cost data puts yearly repairs at $539 against $784 for the class. The 2020 rates about the same. The 2022 rates better.
Oil burning is the problem to watch. The low oil warning often comes on well before the scheduled change, with a quart gone every 2,500 to 4,000 miles, starting between 6,700 and 18,900 miles. Dealers blame defective valve stem seals. Several owners say the fix was slow, disputed, or did not stop the oil use. A few reports are worse: stalling at highway speed, a misfire code that won't clear, and fast loss of oil and coolant. One recall covers seats and seat belts.
Ask for oil consumption and valve stem seal repair records, and confirm the seat and seat belt recall was done. A 2022 is worth a look, since it rates better.
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: Burning oil is the dominant complaint (17 complaints)
- −UNKNOWN OR OTHER issues reported (4 complaints)
Compare 2021 Mazda CX-9 With

2021 Toyota Highlander
Reliability: 70/100

2021 Kia Telluride
Reliability: 63/100

2021 Honda Pilot
Reliability: 63/100

2021 Hyundai Palisade
Reliability: 61/100

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
Engine problems lead owner complaints about the 2021 Mazda CX-9, and 1 recall was issued for it. A VIN check shows whether this car's recall work was done, plus accident, title, and odometer history.
- 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 the dipstick and the date of the last oil change; a low level soon after service points to oil burning.
Ask for dealer records showing whether the valve stem seal repair was done and any oil consumption complaints.
Scan for stored trouble codes, including P0303, and confirm the check engine light stays off.
Check the coolant level and ask whether it has needed frequent top-offs.
Brake hard from moderate speed in an empty lot; listen for clicking or squeaking and watch for brake warning messages.
Confirm no stability control, radar sensor, or reduced engine output warnings appear on the dash during a long test drive.
Back slowly into a parking space and watch for any lurch forward or unexpected acceleration in reverse.
Run a history report; if airbags ever deployed, confirm the rear grab handles and roof trim were replaced.
2021 Mazda CX-9 Common Problems by Component
35 owner complaints grouped by vehicle system.
ENGINE
17 complaintsBurning oil is the dominant complaint. The low oil warning comes on well before the scheduled change, often with a quart gone every 2,500 to 4,000 miles, and some cars run 2 quarts low. Dealers blame defective valve stem seals. Several owners say the fix was slow, disputed, or did not stop the oil use. A smaller group of reports describes more serious trouble: stalling at highway speed, a misfire code that won't clear, and rapid loss of both oil and coolant.
UNKNOWN OR OTHER
4 complaintsSeveral reports here also describe excess oil burning that starts after the first oil change and needs top-offs between services. One complaint describes the vehicle stopping suddenly with a cluster of warnings for the driver-assist sensors, stability control, front radar, and reduced engine output. That creates a rear-end collision risk, and the dealer could not find the root cause. Another reports the doors auto-locking with the key inside and the phone app failing to unlock the car.
POWER TRAIN
2 complaintsSafety-relatedTwo very different failures appear. One crash report, with an injury, describes the car lurching forward and accelerating on its own while the driver was reversing into a parking space. It hit a tree and was a total loss. The other describes a cylinder losing compression at about 60,083 miles. The dealer and Mazda declined to pay because the valve stem seal settlement covers only oil consumption repairs. The owner links the damage to carbon buildup from oil burning.
SERVICE BRAKES (2 complaints)
SERVICE BRAKES
2 complaintsSafety-relatedA crash report describes the brakes letting go about a second into a hard stop. The car rolled into a stopped vehicle, and the phone app then showed a Brake System Malfunction message. The other complaint is about clicking and squeaking brakes that keep coming back. New brakes and rotors at around 22k miles did not fix it. The dealer's service bulletin fix, brake grease, quiets the noise only for about a month.
AIR BAGS (2 complaints)
AIR BAGS
2 complaintsSafety-relatedBoth complaints follow crashes. In one, the driver's front airbag did not deploy in a frontal collision at 10 to 20 mph, and the car shut down afterward. In the other, the right curtain airbag broke the rear grab handle and roof hook into sharp pieces that flew through the cabin. Only two reports are on file, but both concern how well occupants are protected in a crash.
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
Best Mazda CX-9 Years to Buy
Based on reliability index scoreMazda CX-9 Years to Avoid
Mazda CX-9 Reliability Score Trend
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?
Does the 2021 Mazda CX-9 burn oil?
Does the 2021 Mazda CX-9 have any recalls?
Is the 2021 Mazda CX-9 better than the 2022?
Don’t buy a 2021 Mazda CX-9 without checking its VIN first — hidden accidents, title issues, and open recalls could cost you thousands.
How we score the 2021 Mazda CX-9
Of the four inputs behind this score, the 2021 Mazda CX-9 does best on recall impact (88/100) and worst on complaint severity (64/100). Scores weight complaint severity at 35%, repair costs at 30%, recall impact at 20%, and the spread of complaints across systems at 15%, with complaint counts adjusted for US sales. Read the full methodology.
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