YearToAvoid

2021 Mazda CX-9 Reliability Data: Problems & Recalls

Caution The 2021 Mazda CX-9 has a complaint index of 56, ranking 8th worst among 17 model years, earning a Caution verdict. NHTSA lists 39 complaints, 1 recall, 7 crashes and 1 injury, with Engine problems making up 54% of complaints.

Based on NHTSA complaints per model-year, not a reliability rating. Methodology

YearToAvoid Scorecard

Complaint Index
56/100
#8 of 17 CX-9 years
Verdict
Caution
vs. other years of this model
Complaints
39
unique NHTSA reports
Recalls
1
distinct NHTSA campaigns
Crashes
7
reported in complaints
Fires
0
Injuries
1
Top issue
Engine
Best nearby year
2022
rated Best
NHTSA overall rating
5 / 5 ★
EPA combined MPG
23.5
21 city / 27 hwy
Injuries / deaths
1 / 0

Top 2021 Mazda CX-9 problems

Share of this year’s NHTSA complaints by component group. Groups with 15+ complaints have their own page.

  1. Engine21 (54%)
  2. Collision Avoidance & Cameras6 (15%)
  3. Other6 (15%)
  4. Brakes4 (10%)
  5. Transmission & Powertrain4 (10%)
  6. Suspension, Wheels & Tires3 (8%)
  7. Airbags2 (5%)
  8. Electrical System1 (3%)
  9. Steering1 (3%)
  10. Visibility & Wipers1 (3%)

A complaint can list more than one component, so shares add up to more than 100%. Shares are % of complaints.

What owners report

  • Owners report unexpected oil consumption, with some noting low-oil warnings roughly every 3,500 to 4,000 miles.
  • Some describe brakes that suddenly failed to hold or locked up during normal stops, in one case leading to a loss of steering control and an off-road crash.
  • Owners report the backup camera or collision-avoidance system misjudging distance, in one case causing the vehicle to accelerate unexpectedly and crash.
  • Some report the driver-side airbag failing to deploy during a frontal collision.
  • One owner described a rear curtain airbag deployment that broke plastic seat components into sharp pieces inside the cabin.
2021 Mazda CX-9 complaints: complaints filed per month3Feb 2021Aug 2022Feb 2023Sep 2023Jun 2024Nov 2024Jun 2026
39 complaints filed with NHTSA from Feb 2021 to Sep 2026; peak Oct 2024 (3).

2021 Mazda CX-9 recalls

1 NHTSA recall campaign list this model year.

  1. NHTSA 21V750000Sep 27, 2021Structure & Body8,648 vehicles

    Seats:mid/rear assembly

    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."

    Risk: 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.

2021 Mazda CX-9 fuel economy and fuel cost

City
21 MPG
Highway
27 MPG
Combined
23.5 MPG
Annual fuel cost (EPA)
$2,750
15,000 mi/yr
Fuel
Regular
Current regular gas
$4.32/gal
national avg.

EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.

2021 compared with other CX-9 years

Complaint Index by model year (0 = fewest issues, 100 = most)0255075100’07’08’09’10’11’12’13’14’15’16’17’18’19’20’21’22’23
Complaint Index: 0 = fewest issues, 100 = most, relative to other years of this model. Avoid Caution Good Best
YearVerdictIndexComplaintsRecallsMPG
2019Good3853223.5
2020Best619123.5
2021Caution5639123.5
2022Best010023
2023Best1312023

All Mazda CX-9 years: best and worst →

Frequently asked questions

Is the 2021 Mazda CX-9 reliable?
NHTSA data gives the 2021 CX-9 a complaint index of 56 and a Caution verdict, ranking 8th worst out of 17 model years for this model. Engine complaints account for 54% of all reported issues.
What problems does the 2021 Mazda CX-9 have?
NHTSA lists 39 complaints for the 2021 CX-9, with Engine issues like oil consumption being the top problem area at 54% of complaints. Collision Avoidance & Cameras (15%) and Brakes (10%) follow.
Does the 2021 Mazda CX-9 have any recalls?
Yes, NHTSA lists 1 recall for the 2021 CX-9, covering second-row seats that could slide forward unexpectedly during a crash. It is not a do-not-drive recall.
How does the 2021 CX-9 compare to other years?
The 2021 CX-9 has a complaint index of 56, worse than 2019 (38), 2020 (6), 2022 (0), and 2023 (13), all of which rate Good or Best. It ranks 8th worst among 17 model years tracked.
What is the median mileage for engine complaints on the 2021 CX-9?
NHTSA data shows a median mileage of 51,093 miles at failure for engine-related complaints on the 2021 CX-9.

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.