Showing the 2021 CX-9 Signature. NHTSA's VIN data shows it with a 2.5 L engine, but that may not be every version of it, so the numbers below cover every version of this model year. Every version
Owner complaints, recalls, fuel economy and safety ratings from public NHTSA and EPA data, updated Oct 17, 2026.
Fuel economy
23–24 mpgcombined; city 20–22, highway 26–28; every version of this model year
Five years of fuel
$13,530–$14,120U.S. average; Ohio $12,090–$12,620 at local prices; every version of this model year; fuel only, not other costs of owning it; 15,000 miles a year, at EIA fuel prices for the week of Oct 12, 2026
NHTSA's VIN data lists these trims for the 2021 CX-9. A trim's engine and numbers are shown as its own only where EPA names versions after the trim and no other version could be it; "seen with" means a source shows that engine on the trim, not that it was the only one. Recalls and complaints cover the whole model year: whether a recall applies to a car depends on its VIN, on NHTSA's recall lookup.
Owners have filed 40 complaints with NHTSA about the 2021 CX-9. These are unverified owner reports, counted by the part of the car they name; one complaint can name several parts. Counts aren't adjusted for how many were sold, so they don't show how reliable a car is.
Complaints by part of the car
Part
Complaints
Crashes
Fires
Injuries
Engine
21
1
0
0
Unknown or other
6
2
0
1
Power train
5
2
0
1
Forward collision avoidance
4
1
0
1
Service brakes
4
2
0
0
Vehicle speed control
3
1
0
0
Air bags
2
2
0
0
Back over prevention
2
1
0
0
Electrical system
2
0
0
0
Steering
1
1
0
0
Suspension
1
0
0
0
Tires
1
0
0
0
2 more parts
Visibility/wiper
1
0
0
0
Wheels
1
0
0
0
Complaints by model year
Newer years have had less time to collect complaints, and counts aren't adjusted for sales, so a shorter bar doesn't mean a more reliable year.
NHTSA lists 1 recall campaign for the 2021 CX-9 over its history. Campaigns are matched by model and year, so each one may apply to a given car, and its repair may already be done: check a VIN on NHTSA's recall lookup for the open recalls on that exact car.
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.
Carmakers sent NHTSA 428 service bulletins and notices that cover the 2021 CX-9, the latest on Sep 17, 2026. They tell dealers how to fix known issues.
The parts they mention most: electrical system (193), equipment (112), unknown or other (68), engine and engine cooling (55), equipment adaptive/mobility (50).
NHTSA hasn't opened a defect investigation that covers this model year.
Maintenance
Oil
The owner's manual gives the oil and how often to change it. We show oil facts only once we've checked them against the manual, and we haven't yet for the 2021 CX-9.
EPA class: small sport utility vehicle. EPA greenhouse gas score: 5 out of 10. Each version EPA tested:
Swipe the table sideways for more columns.
Version
Engine
Transmission
Fuel
City / hwy / comb
CX-9 Front-Wheel Drive
2.5 L, 4 cyl, turbo
Automatic (S6)
Regular Gasoline
22 / 28 / 24
CX-9 4-Wheel Drive
2.5 L, 4 cyl, turbo
Automatic (S6)
Regular Gasoline
20 / 26 / 23
Sources and dates
U.S. EPA fuel economy data, file of Sep 29, 2026
NHTSA owner complaints, file of Oct 17, 2026
NHTSA recalls, file of Oct 17, 2026
NHTSA manufacturer communications, file of Oct 17, 2026
NHTSA defect investigations, file of Oct 17, 2026
NHTSA 5-Star Safety Ratings, file of Aug 7, 2026
U.S. Energy Information Administration, file of Oct 12, 2026
Fuel cost: EPA mpg with fuel prices for the week of Oct 12, 2026 and electricity prices for Jul 2026. Source: U.S. Energy Information Administration (Oct 2026). Complaints are unverified reports owners filed with NHTSA. About the data