Owner complaints, recalls, fuel economy and safety ratings from public NHTSA and EPA data, updated Oct 17, 2026.
Fuel economy
26–31 mpgcombined; city 23–28, highway 31–36; every version of this model year
Five years of fuel
$10,480–$12,490U.S. average; Ohio $9,360–$11,160 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
Owners have filed 54 complaints with NHTSA about the 2021 Mazda3. 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
19
0
0
0
Electrical system
7
1
2
0
Forward collision avoidance
7
0
0
0
Unknown or other
7
0
0
0
Service brakes
5
0
0
0
Air bags
4
1
0
1
Power train
4
0
0
0
Lane departure
3
0
0
0
Fuel/propulsion system
2
0
0
0
Structure
2
0
0
0
Suspension
2
0
0
0
Vehicle speed control
2
1
0
0
3 more parts
Wheels
2
0
0
0
Seat belts
1
0
0
0
Steering
1
1
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 Mazda3 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 2021 Mazda3 and CX-30 vehicles. Air may suddenly leak from the tire air valve.
Risk: A sudden air leak from the tire air valve may cause a loss of vehicle control while driving, increasing the risk of a crash.
Remedy: Mazda will notify owners, and dealers will replace all four tire air valves with new parts, free of charge. The recall began April 6, 2021. Owners may contact Mazda customer service at 1-800-222-5500 Option 4. Mazda's number for this recall is 4721B.
Carmakers sent NHTSA 634 service bulletins and notices that cover the 2021 Mazda3, the latest on Sep 17, 2026. They tell dealers how to fix known issues.
The parts they mention most: electrical system (248), equipment (140), unknown or other (92), engine and engine cooling (84), engine (82).
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 Mazda3.
EPA class: compact cars. EPA greenhouse gas score: 5–7 out of 10. Each version EPA tested:
Swipe the table sideways for more columns.
Version
Engine
Transmission
Fuel
City / hwy / comb
3 4-Door Front-Wheel Drive
2.0 L, 4 cyl
Automatic (S6)
Regular Gasoline
28 / 36 / 31
3 4-Door Front-Wheel Drive
2.5 L, 4 cyl
Automatic (S6)
Regular Gasoline
26 / 35 / 30
3 4-Door 4-Wheel Drive
2.5 L, 4 cyl
Automatic (S6)
Regular Gasoline
25 / 33 / 28
3 4-Door 4-Wheel Drive
2.5 L, 4 cyl, turbo
Automatic (S6)
Regular Gasoline
23 / 32 / 27
3 5-Door Front-Wheel Drive
2.5 L, 4 cyl
Automatic (S6)
Regular Gasoline
26 / 34 / 29
3 5-Door Front-Wheel Drive
2.5 L, 4 cyl
Manual 6-spd
Regular Gasoline
24 / 33 / 27
3 5-Door 4-Wheel Drive
2.5 L, 4 cyl
Automatic (S6)
Regular Gasoline
25 / 31 / 27
3 5-Door 4-Wheel Drive
2.5 L, 4 cyl, turbo
Automatic (S6)
Regular Gasoline
23 / 31 / 26
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