Last updated: 2026-10-10

2021 Mazda CX-9
RELIABILITY SCORE: 77/100 (GOOD)

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

Complaint Severity64/100

Component-weighted complaints normalized by sales volume

Repair Costs80/100

Independent repair cost ratings

Recall Impact88/100

Recall count weighted by severity

Issue Diversity84/100

Breadth of reported problem categories

The Verdict

Consider

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)

Post-Redesign (Year 6)

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

Common Problem Categories

Safety

LOW RISK
  • 1 manufacturer recall issued

Other

HIGH RISK
  • ENGINE (17)
  • UNKNOWN OR OTHER (4)

See detailed breakdown by component ↓

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 sold

Segment avg: 16.7

LowAvgHigh
Moderate

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.

21V7500002021-09-27

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.

VIN History Report

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.

No VIN? Just hit “Check VIN” to look one up.

  • Accidents
  • Open Recalls
  • Title History
  • Odometer Rollback

2021 Mazda CX-9 NHTSA Safety Ratings

Overall Safety Rating

Overall safety rating: 5 out of 5
Crash Test Results by Configuration (expand)

Gas Powertrain

Driver: 4/5Passenger: 4/5

Rollover risk: 15.1%

Safety Technologies

Dynamic Head Restraints (Not Available)Head Restraint (Driver, Front Passenger, Rear Seat, 3rd row)Advanced Belt Feature (Standard)Adjustable Upper Belt Anchorage (Driver, Front Passenger)Seat Belt Reminder System (Driver, Front Passenger, Rear Seat, 3rd row)Frontal Air Bag (Driver, Front Passenger)Curtain (Driver, Front Passenger, Rear Seat, 3rd row)Torso/Pelvis (Driver, Front Passenger)Knee (Not Available)Additional Air Bags (None)Meets Side Air Bag Out-of-Position Requirements (Yes)LATCH Locations (Rear Seat)Safety Power Windows (Anti-Pinch) (Standard)Safety Power Windows (Anti-Pinch) locations (Driver, Front Passenger, Rear Seat)
View full safety data on NHTSA.gov →

Mazda CX-9Repair Costs & Maintenance

Maintenance Rating

4Maintenance rating: 4 out of 5

Based 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

CX-9
$539
Category Avg
$784
All Vehicles
$652

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
TrimDriveTrans.CityHwyCombFuel Cost
CX-9 2WD 2.5L 4-cylFront-Wheel DriveAutomatic (S6)222824$2,500
CX-9 4WD 2.5L 4-cyl4-Wheel DriveAutomatic (S6)202623$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.

17
4
5
ENGINE (17)UNKNOWN OR OTHER (4)POWER TRAIN (2)SERVICE BRAKES (2)AIR BAGS (2)BACK OVER PREVENTION (1)FORWARD COLLISION AVOIDANCE (1)SUSPENSION (1)Other (5)

ENGINE

17 complaints

Burning 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.

17 complaints total

UNKNOWN OR OTHER

4 complaints

Several 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.

4 complaints total

POWER TRAIN

2 complaintsSafety-related

Two 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.

2 complaints total1 crash1 injury
SERVICE BRAKES (2 complaints)

SERVICE BRAKES

2 complaintsSafety-related

A 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.

2 complaints total1 crash
AIR BAGS (2 complaints)

AIR BAGS

2 complaintsSafety-related

Both 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.

2 complaints total2 crashes
BACK OVER PREVENTION (1 complaints)

BACK OVER PREVENTION

1 complaintSafety-related
2025-12-08Crash reported

Backup 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 complaint
2024-09-03

On [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 complaint
2024-08-15

The 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 complaint
2023-08-01

The 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 complaint
2023-07-08

I 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.

6,700–18,900 milesLow oil warning, oil burning

Best & Worst Mazda CX-9 Years

Best Mazda CX-9 Years to Buy

Mazda CX-9 Years to Avoid

Mazda CX-9 Reliability Score Trend

Scores 0–100. Higher is better. Current year highlighted.

Mazda CX-9 reliability scores by year
YearScoreRating
201866/100Good
201973/100Good
202078/100Good
202177/100Good
202281/100Excellent
202381/100Excellent

Mazda CX-9 Reliability Compared to Other Years

Reliability scores compared across model years
YearScorevs Prior YearRatingRecallsComplaints
202381/1000Excellent012
202281/100+4Excellent09
2021(selected)77/100-1Good135
202078/100+5Good119
201973/100+7Good252
201866/100—Good2125

Frequently Asked Questions

Is the 2021 Mazda CX-9 reliable?
Yes, it rates good and well above average against other 2021 SUVs. Among the CX-9's scored years it lands in the middle. Independent repair-cost data estimates $539 a year in repairs, well under the $784 class figure. The main weakness is oil use, which can be costly if the fix is disputed.
What are the most common problems with the 2021 Mazda CX-9?
Engine trouble leads, with 17 of 35 owner complaints, mostly burning oil. The low oil warning shows up early, and some cars run 2 quarts low. Smaller groups report airbag, power train, and service brake problems, including noisy brakes that keep coming back after new pads and rotors.
Does the 2021 Mazda CX-9 burn oil?
Many owners say so. They report a quart gone every 2,500 to 4,000 miles, with problems starting between 6,700 and 18,900 miles. Dealers point to defective valve stem seals. Some owners found the repair slow or disputed, and a few said it did not stop the oil use.
Does the 2021 Mazda CX-9 have any recalls?
Federal recall records list one recall for this model year, in the seats and seat belts area. Before buying, check the specific vehicle's VIN to confirm that recall repair was completed, since an open recall stays open regardless of who owns the car.
Is the 2021 Mazda CX-9 better than the 2022?
The data favors the 2022. It rates excellent, with 9 complaints and no recalls, against good, 35 complaints, and one recall for the 2021. The 2020 rates about the same as the 2021. Shoppers who want fewer oil worries may lean toward 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.

Look Up a VIN →

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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