2018 Subaru Legacy — MOT failures & pass rate
345 MOT tests on the 2018 Subaru Legacy are in this dataset, and 84.9% of them passed. Large family cars of a similar age fail 11.9% of the time, so this is 3.2pp worse than the group it competes with. Failures cluster in lighting & signalling, suspension and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (7.5%) and suspension (5.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are catalyst emissions, joints and linkage ball joints — catalyst emissions alone was recorded 23 times.
Mileage is the strongest signal on the record: 7.1% of 30-60k cars fail, rising to 19.1% once past 120-150k — 2.7× the risk.
Suspension is the most common advisory, noted on 26.7% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 16.1% in 2021 to 11.1% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.5% | 26 |
| 2 | Suspension | 5.5% | 19 |
| 3 | Emissions & environmental | 4.3% | 15 |
| 4 | Body, structure & corrosion | 4.1% | 14 |
| 5 | Brakes | 2.6% | 9 |
| 6 | Tyres | 1.7% | 6 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 23 |
| 2 | Joints | 11 |
| 3 | Linkage ball joints | 9 |
| 4 | Position lamp | 9 |
| 5 | Pins and bushes | 8 |
| 6 | Rigid brake pipes | 8 |
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 | 26.7% | 92 |
| 2 | Brakes | 16.2% | 56 |
| 3 | Tyres | 14.5% | 50 |
| 4 | Body, structure & corrosion | 12.8% | 44 |
| 5 | Other defects | 8.1% | 28 |
| 6 | Lighting & signalling | 8.1% | 28 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 42 | 7.1% |
| 60-90k | 125 | 13.6% |
| 90-120k | 97 | 15.5% |
| 120-150k | 47 | 19.1% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 87 | 16.1% |
| 2022 | 80 | 17.5% |
| 2023 | 78 | 15.4% |
| 2024 | 55 | 12.7% |
| 2025 | 45 | 11.1% |
What to check before buying a 2018 Legacy
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.5% of tests. Start there.
- Lighting & signalling (7.5% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (5.5% 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.
- Emissions & environmental (4.3% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 2018 Subaru Legacys pass their MOT?
84.9% of the 345 2018 Subaru Legacy MOT tests in this dataset passed — a 15.1% fail rate.
What is the most common MOT failure on a 2018 Subaru Legacy?
Lighting & signalling, recorded in 7.5% of tests, followed by suspension (5.5%).
Does the 2018 Legacy get worse with mileage?
Its MOT fail rate rises from 7.1% in the 30-60k band to 19.1% in the 120-150k band.
Methodology & source. Based on 345 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.