1991 Ford Sierra Sapphire — MOT failures & pass rate
342 MOT tests on the 1991 Ford Sierra Sapphire are in this dataset, and 89.5% of them passed. All cars of a similar age fail 22.4% of the time, so this is 11.8pp better than the group it competes with. Failures cluster in lighting & signalling, suspension and body, structure & corrosion.
What the MOT record shows
No single area dominates — lighting & signalling (5.6%) and suspension (4.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp, headlamp aim and prescribed areas — headlamp alone was recorded 14 times.
Mileage matters less than usual here: the 1991 Sierra Sapphire fails 8.6% of the time in the 0-30k band and 11.5% at 90-120k, a spread of only 3.0 points.
Brakes is the most common advisory, noted on 10.5% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 13.4% in 2021 to 4.8% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.6% | 19 |
| 2 | Suspension | 4.1% | 14 |
| 3 | Body, structure & corrosion | 3.8% | 13 |
| 4 | Brakes | 3.2% | 11 |
| 5 | Emissions & environmental | 2.9% | 10 |
| 6 | Visibility | 2.6% | 9 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp | 14 |
| 2 | Headlamp aim | 9 |
| 3 | Prescribed areas | 9 |
| 4 | Component mounting prescribed areas | 8 |
| 5 | Non catalyst emissions | 8 |
| 6 | Wipers | 6 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 10.5% | 36 |
| 2 | Emissions & environmental | 8.5% | 29 |
| 3 | Suspension | 6.7% | 23 |
| 4 | Tyres | 5.6% | 19 |
| 5 | Lighting & signalling | 4.4% | 15 |
| 6 | Body, structure & corrosion | 3.2% | 11 |
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 | 117 | 8.6% |
| 30-60k | 86 | 8.1% |
| 60-90k | 83 | 14.5% |
| 90-120k | 52 | 11.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 82 | 13.4% |
| 2022 | 73 | 13.7% |
| 2023 | 69 | 10.1% |
| 2024 | 56 | 8.9% |
| 2025 | 62 | 4.8% |
What to check before buying a 1991 Sierra Sapphire
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 5.6% of tests. Start there.
- Lighting & signalling (5.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (4.1% 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.
- Body, structure & corrosion (3.8% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
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 1991 Ford Sierra Sapphires pass their MOT?
89.5% of the 342 1991 Ford Sierra Sapphire MOT tests in this dataset passed — a 10.5% fail rate.
What is the most common MOT failure on a 1991 Ford Sierra Sapphire?
Lighting & signalling, recorded in 5.6% of tests, followed by suspension (4.1%).
Does the 1991 Sierra Sapphire get worse with mileage?
Its MOT fail rate rises from 8.6% in the 0-30k band to 11.5% in the 90-120k band.
Methodology & source. Based on 342 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.