2021 Ford Fiesta St-Line T Mhev — MOT failures & pass rate
Across 10,088 MOT tests analysed for the 2021 Ford Fiesta St-Line T Mhev, the most common recorded failure areas were lighting & signalling, tyres and visibility. Its pass rate of 93.4% was above the average for cars of a similar age (91.3%). Higher-mileage examples failed more often — 13.3% in the 60-90k group versus 5.1% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.7% | 574 |
| 2 | Tyres | 3.9% | 390 |
| 3 | Visibility | 1.6% | 162 |
| 4 | Brakes | 0.9% | 86 |
| 5 | Emissions & environmental | 0.4% | 37 |
| 6 | Seat belts & restraints | 0.3% | 32 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 764 |
| 2 | Tread depth | 301 |
| 3 | Washers | 136 |
| 4 | Wipers | 43 |
| 5 | Brake pads | 41 |
| 6 | Headlamp | 31 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 21.4% | 2,159 |
| 2 | Brakes | 5.8% | 584 |
| 3 | Other defects | 4.9% | 497 |
| 4 | Road wheels | 1.9% | 195 |
| 5 | Visibility | 1.4% | 136 |
| 6 | Lighting & signalling | 0.5% | 53 |
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 | 6,912 | 5.1% |
| 30-60k | 2,975 | 9.7% |
| 60-90k | 188 | 13.3% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 10,025 | 6.6% |
| Hybrid | 63 | 3.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 393 | 6.1% |
| 2024 | 4,815 | 6.5% |
| 2025 | 4,873 | 6.7% |
What to check before buying a 2021 Fiesta St-Line T Mhev
Before buying a 2021 Ford Fiesta St-Line T Mhev, focus on the areas it most often fails on. Lighting & signalling accounted for 5.7% of tests for this year.
- Lighting & signalling (5.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (3.9% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Visibility (1.6% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 2021 Ford Fiesta St-Line T Mhevs pass their MOT?
93.4% of the 10,088 2021 Ford Fiesta St-Line T Mhev MOT tests in this dataset passed — a 6.6% fail rate.
What is the most common MOT failure on a 2021 Ford Fiesta St-Line T Mhev?
Lighting & signalling, recorded in 5.7% of tests, followed by tyres (3.9%).
Does the 2021 Fiesta St-Line T Mhev get worse with mileage?
Its MOT fail rate rises from 5.1% in the 0-30k band to 13.3% in the 60-90k band.
Methodology & source. Based on 10,088 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.