2021 Mazda Mazda3: what breaks, and at what mileage
What breaks on the 2021 Mazda Mazda3
On the 2021 Mazda Mazda3, the failure owners report most often is excessive oil consumption, with 10 reports on file. Across every failure mode on this year, half the dated reports were filed before 0 miles. Overall it scores 86 out of 100, severe risk for a 2021.
Severe risk for a 2021 — 3rd riskiest of the 231 2021 vehicles we can rate. 66 owner reports; fleet size estimated from this year's own recall paperwork.
What breaks on the 2021 Mazda Mazda3
Owners have reported 23 named failure modes on the 2021 Mazda Mazda3, and the three most-reported carry 39% of everything filed.
Excessive oil consumption leads with 10 reports and about 33 per 1,000 vehicles.
Lane keep or steering assist fault follows with 8 reports, median 0 miles.
Other engine problem follows with 8 reports.
By system, the reports fall mostly into engine (18), adas (16) and electrical (5).
At what mileage it happens
Too few of the reports on this year carry an odometer reading to describe the timing: 4 of them do. The mileages quoted elsewhere on this page come from the modes that have enough of them.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
Showing the 12 most-reported failure modes of 23. The full list is in the table below.
How reports accumulate
Every report with an odometer reading, cumulative, from 0 to 200,000 miles. A curve that climbs early is a car with early problems, whatever its total.
- Line share of reports filed by that mileage
Severity, and what it costs
Across the named modes, 3 mention a crash and 2 a fire. Those are the words owners used in their own complaints, and NHTSA does not verify them, but they are the closest thing in this data to a measure of what a failure actually did.
The average severity weight across every report on this year is 4.11, where a stalled engine or a failed airbag weighs many times more than a rattling trim panel, and a figure this high means the reports are dominated by failures with safety consequences rather than annoyances. The weighting is set out in full on the methodology page.
What the top failures cost to put right, as editorial estimates for an independent US shop rather than figures from NHTSA: excessive oil consumption at $900–$6,500, lane keep or steering assist fault at $200–$1,600, other engine problem at $300–$4,000 and other driver assistance problem at $250–$1,800. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.
33% of the reports on this year sit in the engine, transmission, drivetrain or cooling systems — the four where a repair bill is usually four figures.
Every reported failure mode
| Failure mode | System | Reports | With reading | 25th | Median | 75th | Per 1,000 | Typical repair | Severity |
|---|---|---|---|---|---|---|---|---|---|
| Excessive oil consumption | engine | 10 | 0 | — | — | — | 33.4 | $900–$6,500 | High |
| Lane keep or steering assist fault | adas | 8 | 1 | — | 2k | — | 26.8 | $200–$1,600 | High |
| Other engine problem | engine | 8 | 0 | — | — | — | 26.8 | $300–$4,000 | High |
| Other driver assistance problem | adas | 5 | 0 | — | — | — | 16.7 | $250–$1,800 | High |
| Other electrical problem | electrical | 4 | 2 | — | 2k | — | 13.4 | $250–$2,000 | Moderate |
| Other brake problem | brakes | 4 | 0 | — | — | — | 13.4 | $300–$1,800 | High |
| Differential or transfer case failure | drivetrain | 2 | 0 | — | — | — | 6.7 | $900–$4,200 | High |
| Other fuel system problem | fuel | 2 | 0 | — | — | — | 6.7 | $300–$2,200 | High |
| Other wheel or tire problem | wheels | 2 | 0 | — | — | — | 6.7 | $200–$1,500 | High |
| Other body or interior problem | body | 2 | 0 | — | — | — | 6.7 | $200–$2,000 | Moderate |
| Overheating | cooling | 1 | 0 | — | — | — | 3.3 | $400–$3,500 | High |
| Thermostat failure | cooling | 1 | 0 | — | — | — | 3.3 | $250–$900 | Moderate |
| Fuel pump failure | fuel | 1 | 0 | — | — | — | 3.3 | $600–$2,600 | High |
| Wiring harness or short circuit | electrical | 1 | 0 | — | — | — | 3.3 | $400–$3,500 | High |
| Parking brake failure | brakes | 1 | 0 | — | — | — | 3.3 | $250–$1,300 | Moderate |
| Seat belt or retractor failure | airbag | 1 | 0 | — | — | — | 3.3 | $200–$900 | High |
| Cruise control failure | adas | 1 | 0 | — | — | — | 3.3 | $200–$1,400 | High |
| Blind spot monitor failure | adas | 1 | 1 | — | 2k | — | 3.3 | $250–$1,300 | Moderate |
| Control arm, ball joint or bushing failure | suspension | 1 | 0 | — | — | — | 3.3 | $400–$2,200 | High |
| Sunroof failure or glass breakage | body | 1 | 0 | — | — | — | 3.3 | $700–$4,500 | High |
| Tail light, brake light or signal failure | lighting | 1 | 0 | — | — | — | 3.3 | $100–$900 | Moderate |
| Other steering problem | steering | 1 | 0 | — | — | — | 3.3 | $350–$2,400 | High |
| Other speed control problem | adas | 1 | 0 | — | — | — | 3.3 | $250–$2,000 | Critical |
| Unclassified problem | other | 6 | 0 | — | — | — | 20.1 | — | Moderate |
Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound. Repair costs are typical independent-shop ranges for the failure, not figures from these reports.
How often, against how many were built
Scaled by an estimate of how many of these cars exist, the 2021 Mazda Mazda3 draws about 221 per 1,000 vehicles, which puts it in the 99th percentile of complaint rates among 2021 vehicles we can rate.
That denominator is the weakest number on the page and it is fair to say so plainly. Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound.
The working figure is 299 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2021 vehicles, which is what the risk score uses, is far more robust than the rate itself.
Recalls on the 2021 model year
NHTSA has issued 1 recall campaign covering the 2021 Mazda Mazda3, affecting an estimated 299 vehicles. A recall is a different kind of evidence from a complaint: it is the regulator and the manufacturer agreeing that something has to be fixed, and the fix is free for as long as the car exists.
The campaigns cover tires:valve. Whether the work was actually done on the car in front of you is a question only the VIN can answer, and the manufacturer or NHTSA will answer it free.
One caution about reading these together: a recall usually raises the complaint count for the same part, because owners who read about it go and file. The mileages stay informative; the counts get noisy.
TIRES:VALVE
599 vehicles 2021-02-22- Defect
- Mazda North American Operations (Mazda) is recalling certain 2021 Mazda3 and CX-30 vehicles. Air may suddenly leak from the tire air valve.
- Consequence
- 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.
Recall work is free at a franchised dealer regardless of the car's age. Check the VIN at nhtsa.gov/recalls before assuming it was done.
How it ranks in the 2021 field
The score at the top of the page, placed among its peers. The zones are the same thresholds the scorer applies, read out of the scorer itself, so the picture and the band word cannot disagree.
Scores are ranked within the model year, never across years, because an older car has had longer to accumulate reports.
- Left fewer and less serious reports
- Right more, or worse
- Marker this vehicle
Better and worse years of the same car
Severe risk for a 2021 — 3rd riskiest of the 231 2021 vehicles we can rate. Every score on this site is a rank inside its own model year, which is what makes a 2004 and a 2019 comparable at all.
Across the 21 model years of this car that carry enough reports to score, 2005 comes out best at 64 and 2021 worst at 86, with 2021 itself at 86.
If the model year is negotiable, 2005, 2017, 2013, 2007, 2004, 2016, 2006, 2010, 2015, 2022, 2014, 2018, 2011, 2008, 2012, 2009, 2020, 2023, 2019 and 2024 score lower than 2021 by a margin worth acting on. Same body, same engines, different luck — usually a supplier change or a mid-cycle fix, which the complaint data can show but never explain.
Within the 2019–2021 generation specifically, 2020 is the strongest year at 73 and 2021 the weakest at 86.
Scores compare each year against other cars of the same model year, so a low number on an older car is a real result and not an artefact of age.
Shorter is better. Years with too few reports to score are shown without a bar rather than as a zero, because no data is not good news.
Within the 2019-2021 generation, 2020 Mazda Mazda3 scores best at 73 and 2021 Mazda Mazda3 worst at 86.
What this page cannot tell you
66 owner reports; fleet size estimated from this year's own recall paperwork. Every count on this page is therefore a floor: it is the number of owners who went to the trouble of filing with a federal agency, which is a small and self-selected fraction of the owners who had the fault.
Of those 66 reports, 4 carried an odometer reading, so the mileages here describe 6% of the sample rather than all of it. Owners also round: readings pile up on multiples of ten thousand, which is why this site publishes "about 90,000 miles" and not "91,438".
The failure modes are assigned by software reading the owner's own words, which is accurate in bulk and wrong in individual cases. A mode with a handful of reports may contain a misfiled one.
And nothing here predicts what one car will do. These are other people's complaints, filed years apart, on cars maintained by strangers. Read the page as a map of where this model year has previously gone wrong, then have the specific car in front of you inspected.
Questions this page answers
What are the most common problems with the 2021 Mazda Mazda3?
The most-reported failures are excessive oil consumption (10 reports), lane keep or steering assist fault (8 reports, median 0 miles) and other engine problem (8 reports). Counts come from owner complaints filed with NHTSA, which are voluntary, so they show what owners bothered to report rather than every fault that occurred.
Is the 2021 Mazda Mazda3 reliable?
It scores 86 out of 100 on our risk index, which is severe — 3rd riskiest of the 231 2021 vehicles we can rate. The score is a comparison against other 2021 vehicles, not a prediction about any individual car, and it is built from complaint rates, severity and how early failures appear.
Which year of the Mazda Mazda3 is best?
Within the 2019–2021 generation, 2020 scores best at 73 out of 100 and 2021 worst at 86. Same body, same engines, different luck.
Where this comes from. Every figure above is computed from NHTSA owner complaints and recall records for this exact make, model and year. Complaints are voluntary and self-selected, so treat counts as a floor. The methodology page writes out each formula, and the same numbers are available as JSON.
What breaks at my mileage Compare with another car
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed