Model Reports 8 min read Updated 12 Jul 2026

Mazda CX-5 2021: reliability & common MOT faults

Common MOT faults and peer comparisons for the 2021 Mazda CX-5 using test year 2025 from UK DVSA open data. Available test years: 2024, 2025.

627 failed first-attempt tests · 5,319 first tests (test year 2025)

UK DVSA MOT open data for this registration year, compared with similar age and mileage peers.

Wear patterns

These patterns look like wear or usage effects rather than model-specific design faults. Tyres, brake friction material, and alignment-related defects often track mileage and road use. They are not treated as a model design fault in our common-faults ranking.

# Pattern Location Failures vs similar cars Share of fails Confidence
1 Brake pads (front)
Brakes > Mechanical brake components > Brake linings and pads > Brake pads
 Front 108 ×3.3 17.2% Wear / usage pattern — not treated as a model design fault

Advisories

Advisory items recorded on failed first-attempt tests that appear elevated versus peers. Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.

# Advisory pattern Location Notes vs similar cars Share Confidence
1 Brake discs (rear)
Brakes > Mechanical brake components > Brake discs and drums > Brake discs
 Rear 93 ×2.1 14.8% Wear / usage pattern — not treated as a model design fault

FAQs

We do not show a single reliability score for the 2021 Mazda CX-5 on this page. Among 627 failed first-attempt MOT tests (test year 2025), We surface elevated MOT failure patterns versus similar age and mileage peers when they clear display floors. Treat this as a pre-purchase checklist from DVSA open data — not a guarantee for any individual car.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that look elevated versus peers among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights elevated MOT failure patterns for the 2021 Mazda CX-5 (registration year) using UK DVSA open data for the selected test year. Patterns are ranked against similar age and mileage peers. It is a buyer checklist from MOT defect statistics — not a full service history or manufacturer TSB list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.
PRS means the vehicle failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
We count how often each MOT defect pattern appears among failed first-attempt tests for this model year, then compare that with peers. We compare this model year with other class 4 cars of similar age and mileage in the same test year, excluding the whole model family so the car is not compared with itself (leave-one-out peer baseline). A higher lift means the pattern shows up more often than expected for similar ca…
No. Common faults are inferred from MOT defect statistics, not manufacturer technical service bulletins or safety recalls. An elevated pattern is a statistical signal versus peers — useful as a pre-purchase check point, not proof of a design defect on any individual car.
Often not. Tyre, brake friction, and aim/alignment patterns frequently track wear and usage. We list them separately so they are not treated as model design faults in the common faults ranking.

About this data

Universe. UK class 4 cars only; normal MOT tests (not retests); results pass, PRS, or fail; one first test per vehicle per calendar year.

PRS policy. PRS means the vehicle failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

Peer baseline. We compare this model year with other class 4 cars of similar age and mileage in the same test year, excluding the whole model family so the car is not compared with itself (leave-one-out peer baseline).

Data years. Test years covered: 2024, 2025.

Limitations.

  • MOT tests do not cover engine internals, gearboxes, or many electronic modules — so this is not a full reliability score.
  • Common faults are inferred from MOT defect statistics, not manufacturer TSBs or recalls.
  • Matching on age and mileage reduces but does not remove every usage or maintenance difference between cars.
  • Pass rates and star scores appear only when those data marts are available; this page never invents them.

Display rules config: 1

Contains public sector information licensed under the Open Government Licence v3.0.

Most reliable Mazda models

See brand-wide MOT rankings and year guidance for Mazda (separate from this model-year report).