2,376 tests in 2025
Ford Sierra reliability and MOT pass rate
90.2% passed first time. The 9.8% fail rate is 12.8 points better than the all-car average, on a median example 36 years old with 52,773 miles.
Pass rate
90.2%
22.6% of all cars failed; 9.8% of these did.
Fixed on the day
2.1%
Passed after a defect was put right during the visit.
Median at test
52,773 mi
36 years old.
Fail rate by age
| Age at test | Tests | Fail rate |
|---|---|---|
| 3-5 years | 0 | — |
| 6-9 years | 0 | — |
| 10-13 years | 0 | — |
| 14+ years | 2,376 | 9.8% |
What the Sierra fails on
Share of failed tests with at least one fail item in each DVSA inspection section. A test can fail in several sections at once.
- Lamps, reflectors and electrical equipment4 dangerous33.9%
- Suspension3 dangerous33%
- Noise, emissions and leaks3 dangerous30.9%
- Brakes18 dangerous28.3%
- Body, chassis, structure8 dangerous24.9%
- Visibility13.3%
- Steering2 dangerous12%
- Seat belts and supplementary restraint systems9.4%
Is the Sierra getting worse?
The fail rate fell 3.7 points to 10.3% from 2022 to 2025 while the median one tested aged 3 years. Ageing alone would predict about 0 points, so it is holding up better than the fleet average for its age.
| Year | Tests | Median age | Fail rate | All cars | |
|---|---|---|---|---|---|
| 2022 | 2,517 | 33 | 14% | 22.5% | |
| 2023 | 2,437 | 34 | 12.3% | 22.8% | |
| 2024 | 1,916 | 35 | 11.4% | 23.2% | |
| 2025 | 2,004 | 36 | 10.3% | 22.6% |
Fail rate is first attempts at class 4 tests. Median age is the age of a typical Sierra at its test that year, and it is the number to watch: across the whole fleet each extra year of age adds roughly 1.9 points to the fail rate, so a model whose age and fail rate rise together is simply getting older.
The exact defects that fail it
Every failure item DVSA recorded against a Sierra in 2025, counted by how many tests each one appeared on.
- 1Component mounting prescribed areas: prescribed area excessively corroded significantly reducing structural strength32 tests
- 2Non catalyst emissions: emissions carbon monoxide content excessive29 tests
- 3Prescribed areas: prescribed area strength or continuity significantly reduced17 tests
- 4Integral vehicle structure condition: corroded to the extent that the rigidity of the assembly is significantly reduced14 tests
- 5Horn: not working14 tests
- 6Service brake performance: excessively binding13 tests
- 7Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt13 tests
- 8Emissions not tested: unable to be completed12 tests
What wears out first
Advisories are the tester flagging wear that is still legal. A typical Sierra collects 2.73 of them per test, and these are the ones that come up most. Treat it as the running-repairs list for the next year or two.
- 1Engine oil leaks: leaking excessively from engine172 tests
- 2Rigid brake pipes: excessively corroded80 tests
- 3Pins and bushes: pin or bush excessively worn60 tests
- 4Tread depth: tread depth below requirements of 1.6mm55 tests
- 5Exhaust system: has a major leak of exhaust gases55 tests
- 6Condition: has a tear, caused by separation or partial failure of its structure54 tests
- 7Brake discs: in such a condition that it is seriously weakened47 tests
- 8Coil spring: corroded so that its cross sectional area is reduced and seriously weakened43 tests
Questions
What is the Ford Sierra MOT pass rate?
90.2% of the 2,376 Ford Sierra first-attempt MOTs in 2025 passed. The fail rate of 9.8% compares with 22.6% across all cars. A further 2.1% passed after a defect was fixed during the test visit.
What does a Ford Sierra usually fail on?
The single most common failure is "Component mounting prescribed areas: prescribed area excessively corroded significantly reducing structural strength", recorded on 32 failed tests, followed by "Non catalyst emissions: emissions carbon monoxide content excessive" and "Prescribed areas: prescribed area strength or continuity significantly reduced". By section, lamps, reflectors and electrical equipment appears in 33.9% of failures, suspension appears in 33% of failures, noise, emissions and leaks appears in 30.9% of failures.
Does age change the odds?
Sharply. At 3 to 5 years old the fail rate was n/a%; at 14+ years it was 9.8%. The median Ford Sierra tested in 2025 was 36 years old with 52,773 miles.
Is the Ford Sierra getting less reliable?
The fail rate fell 3.7 points to 10.3% from 2022 to 2025 while the median one tested aged 3 years. Ageing alone would predict about 0 points, so it is holding up better than the fleet average for its age.
First-attempt class 4 tests, 2025, from DVSA’s anonymised MOT data (OGL v3, retrieved 2026-09-12). DVSA records newer cars trim by trim; this page adds every Sierra trim together. Year-on-year figures come from the same DVSA extracts for 2026 and earlier years. Full method on the pass rates hub.
Other Ford models
- Fiesta 27.3%
- Focus 25.4%
- Escort 17.6%
- Edge 13.1%
- Mustang Mach-E 8%
- Allied 18.2%
- Unclassified 18.4%
- Capri 13.8%
- Roller Team 8%
- Chausson 6.4%
Checking a particular Sierra?
The odds above are the model. The car in front of you has its own record: every test, every advisory, the mileage at each one.
Due a test? Find an approved MOT station near you.