Mercedes-Benz A-Class MOT pass rate & common failures
The Mercedes-Benz A-Class appears in 1,863,616 MOT tests spanning model years 1998–2025, and 85.1% of them passed. Small family cars of a similar age fail at 15.0%, so the A-Class sits squarely on the average. Its most common failure areas are tyres, lighting & signalling and suspension.
Best and worst A-Class years
Ranked across A-Class years with at least 1,000 tests. Older cars fail more simply because they are older — compare years close together in age before drawing conclusions.
What the MOT record shows
The strongest year on this record is 2022 (92.9% pass rate); the weakest is 1999 (69.6%). Older cars carry more of the difference than the average implies.
No single area dominates — tyres (5.9%) and lighting & signalling (5.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, tread depth and washers — headlamp aim alone was recorded 51,189 times.
Condition tracks the odometer closely. Failures run at 7.4% in the 0-30k band and 26.6% in the 150k+ band, a 19.2-point spread — more than double.
The hybrid cars hold up better: 8.9% fail against 15.7% for diesel, a 6.8-point gap across 1,036,729 tests.
Tyres is the most common advisory, noted on 25.9% of tests — work that passed today but is likely due soon.
How it compares
Versions & engines
MOT records broken out by the engine designations buyers actually search for.
By model year
Every A-Class model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 1998 | 242 | 69.0% | 31.0% | Lighting & signalling |
| 1999 | 1,635 | 69.6% | 30.4% | Lighting & signalling |
| 2000 | 2,428 | 69.8% | 30.2% | Lighting & signalling |
| 2001 | 5,544 | 71.9% | 28.1% | Lighting & signalling |
| 2002 | 8,705 | 70.7% | 29.3% | Lighting & signalling |
| 2003 | 11,674 | 71.7% | 28.3% | Lighting & signalling |
| 2004 | 11,021 | 71.8% | 28.2% | Lighting & signalling |
| 2005 | 23,999 | 74.3% | 25.7% | Lighting & signalling |
| 2006 | 34,980 | 74.1% | 25.9% | Lighting & signalling |
| 2007 | 43,406 | 75.4% | 24.6% | Lighting & signalling |
| 2008 | 46,843 | 75.0% | 25.1% | Lighting & signalling |
| 2009 | 46,758 | 76.3% | 23.7% | Lighting & signalling |
| 2010 | 40,839 | 77.6% | 22.4% | Lighting & signalling |
| 2011 | 34,761 | 79.7% | 20.3% | Lighting & signalling |
| 2012 | 33,415 | 80.1% | 19.9% | Lighting & signalling |
| 2013 | 97,105 | 80.9% | 19.1% | Suspension |
| 2014 | 143,415 | 82.0% | 17.9% | Tyres |
| 2015 | 158,855 | 84.0% | 16.0% | Tyres |
| 2016 | 221,222 | 85.9% | 14.1% | Tyres |
| 2017 | 232,506 | 87.5% | 12.5% | Tyres |
| 2018 | 230,140 | 89.4% | 10.6% | Tyres |
| 2019 | 230,028 | 89.9% | 10.1% | Tyres |
| 2020 | 118,106 | 91.3% | 8.7% | Tyres |
| 2021 | 65,243 | 92.3% | 7.7% | Tyres |
| 2022 | 19,931 | 92.9% | 7.1% | Tyres |
| 2023 | 773 | 95.7% | 4.3% | Tyres |
| 2024 | 37 | 91.9% | 8.1% | Tyres |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.9% | 110,582 |
| 2 | Lighting & signalling | 5.1% | 95,429 |
| 3 | Suspension | 3.9% | 73,157 |
| 4 | Brakes | 3.6% | 67,491 |
| 5 | Visibility | 3.3% | 60,704 |
| 6 | Emissions & environmental | 1.8% | 33,549 |
| 7 | Seat belts & restraints | 1.5% | 26,976 |
| 8 | Body, structure & corrosion | 1.1% | 19,898 |
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 | 51,189 |
| 2 | Tread depth | 50,637 |
| 3 | Washers | 42,664 |
| 4 | Brake pads | 38,554 |
| 5 | Coil spring | 38,475 |
| 6 | Malfunction indicator lamp | 27,473 |
| 7 | Wipers | 24,169 |
| 8 | SRS malfunction indicator lamp | 23,407 |
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 | 25.9% | 481,812 |
| 2 | Brakes | 19.6% | 365,775 |
| 3 | Other defects | 7.4% | 138,824 |
| 4 | Suspension | 6.5% | 120,744 |
| 5 | Visibility | 3.6% | 67,337 |
| 6 | Lighting & signalling | 2.3% | 42,677 |
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 | 377,089 | 7.4% |
| 30-60k | 715,281 | 12.7% |
| 60-90k | 472,989 | 18.5% |
| 90-120k | 208,818 | 23.2% |
| 120-150k | 65,115 | 25.3% |
| 150k+ | 19,980 | 26.6% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 999,339 | 15.7% |
| Petrol | 826,883 | 14.3% |
| Hybrid | 37,390 | 8.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 298,186 | 14.6% |
| 2022 | 349,439 | 14.3% |
| 2023 | 384,846 | 14.9% |
| 2024 | 408,683 | 15.1% |
| 2025 | 422,462 | 15.5% |
What to check before buying a Mercedes-Benz A-Class
- Tyres (5.9% 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.
- Lighting & signalling (5.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (3.9% 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.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
What is the MOT pass rate for the Mercedes-Benz A-Class?
85.1% of the 1,863,616 Mercedes-Benz A-Class MOT tests in this dataset passed, a 14.9% fail rate, across model years 1998–2025.
What does the Mercedes-Benz A-Class most often fail its MOT on?
Tyres, recorded in 5.9% of tests, then lighting & signalling (5.1%).
Which A-Class years are best and worst for MOT results?
2022 has the best pass rate at 92.9% and 1999 the weakest at 69.6%, from 19,931 and 1,635 tests respectively.
How much does mileage affect A-Class MOT results?
Fail rates run at 7.4% for cars in the 0-30k band and 26.6% for 150k+, a 19.2-point difference.
Is the hybrid or diesel A-Class more reliable at MOT time?
On MOT-testable defects the hybrid fails 8.9% of the time against 15.7% for the diesel. This covers testable items only, not engine or gearbox reliability.
Methodology & source. Based on 1,863,616 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.