2004 Mazda 6 — MOT failures & pass rate
Across 3,660 MOT tests analysed for the 2004 Mazda 6, the most common recorded failure areas were suspension, lighting & signalling and brakes. Its pass rate of 67.0% was below the average for large family cars of a similar age (72.2%). Higher-mileage examples failed more often — 40.4% in the 150k+ group versus 11.1% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 18.3% | 668 |
| 2 | Lighting & signalling | 16.9% | 617 |
| 3 | Brakes | 14.4% | 527 |
| 4 | Body, structure & corrosion | 7.8% | 286 |
| 5 | Visibility | 6.0% | 219 |
| 6 | Tyres | 5.3% | 192 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Component mounting prescribed areas | 794 |
| 2 | Position lamp | 277 |
| 3 | Prescribed areas | 231 |
| 4 | Integral vehicle structure condition | 228 |
| 5 | Headlamp aim | 209 |
| 6 | Rbt (sp) | 209 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 39.4% | 1,443 |
| 2 | Brakes | 30.7% | 1,122 |
| 3 | Tyres | 27.5% | 1,008 |
| 4 | Body, structure & corrosion | 16.5% | 605 |
| 5 | Lighting & signalling | 14.8% | 541 |
| 6 | Other defects | 13.3% | 485 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 36 | 11.1% |
| 30-60k | 411 | 25.1% |
| 60-90k | 1,085 | 29.3% |
| 90-120k | 1,080 | 34.8% |
| 120-150k | 724 | 38.1% |
| 150k+ | 324 | 40.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 3,479 | 32.7% |
| Diesel | 181 | 39.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,293 | 33.5% |
| 2022 | 897 | 33.8% |
| 2023 | 646 | 33.1% |
| 2024 | 482 | 32.2% |
| 2025 | 342 | 30.1% |
What to check before buying a 2004 6
Before buying a 2004 Mazda 6, focus on the areas it most often fails on. Suspension accounted for 18.3% of tests for this year.
- Suspension (18.3% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Lighting & signalling (16.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (14.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2004 Mazda 6s pass their MOT?
67.0% of the 3,660 2004 Mazda 6 MOT tests in this dataset passed — a 33.0% fail rate.
What is the most common MOT failure on a 2004 Mazda 6?
Suspension, recorded in 18.3% of tests, followed by lighting & signalling (16.9%).
Does the 2004 6 get worse with mileage?
Its MOT fail rate rises from 11.1% in the 0-30k band to 40.4% in the 150k+ band.
Methodology & source. Based on 3,660 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.