Car
Audi A3
82.6%
pass rate across 1,454,375 tests
79.4% first-time pass rate
Audi A3 vs Mercedes-Benz A-Class
The two cars compared on 2,305,125 real MOT tests: pass rates, first-time passes, the failures each is known for, repair costs and how both have moved year by year.
82.5%
pass rate across 850,750 tests
79.2% first-time pass rate
The short answer
Too close to call on MOT evidence
The two are level on first-time passes: 79.4% for the Audi A3 and 79.2% for the Mercedes-Benz A-Class. Even after adjusting for the age and mileage of the cars tested, the Audi A3 is +2.3 points against its expected rate, the Mercedes-Benz A-Class +0.4. A typical repair bill is similar: £41–£104 for the Audi A3 and £33–£82 for the Mercedes-Benz A-Class; at their pass rates that is roughly £709–£1,815 versus £573–£1,439 per 100 tests.
- First-time pass: 79.4% vs 79.2%.
- All MOTs: 82.6% vs 82.5%.
- Like-for-like: +2.3 vs +0.4 points.
- Typical repair bill: £41–£104 vs £33–£82.
- At 90,000–120,000 miles: 79.0% vs 76.9%.
| Measure | A3 | A-Class |
|---|---|---|
| MOT tests on record | 1,454,375 | 850,750 |
| Pass rate, all MOTs | 82.6% stronger figure | 82.5% |
| First-time pass rate | 79.4% stronger figure | 79.2% |
| Against the UK average | +1.6 pts stronger figure | +1.5 pts |
| Like-for-like, age and mileage adjusted | +2.3 pts stronger figure | +0.4 pts |
| Average mileage at test | 95,023 mi | 73,044 mi |
| Model years on record | 2000–2023 (24) | 2000–2021 (22) |
| Best model year | 2023 · 94.4% | 2021 · 93.0% |
| Worst model year | 2004 · 70.7% | 2000 · 70.6% |
| Typical repair bill | £41–£104 | £33–£82 stronger figure |
| Expected repair spend per 100 tests | £709–£1,815 | £573–£1,439 stronger figure |
| Main fuel | Diesel 51% | Diesel 61% |
| Variants recorded | 3 | 4 |
A ✓ marks the stronger figure in each row. It is a comparison between the two cars, not a judgement against the national average.
What goes wrong most often
The most common priced failures on each model, as a share of all its tests. Repair costs are estimates from UK parts data, not quotes.
A3
- Suspension arm corroded 3.5% £35–£85
- Linkage ball joint dust cover insecure 1.5% £18–£45
- Linkage ball joint dust cover deteriorated 1.2% £18–£45
A-Class
- Linkage ball joint dust cover deteriorated 1.5% £18–£45
- SRS warning lamp indicates a fault 1.5% £3–£12
- Flexible brake hoses excessively deteriorated 1.2% £25–£70
- Side repeaters not working 0.8% £5–£25
Year by year
The newest 8 years with published results. A model's headline rate hides a wide spread between its best and worst years.
| Model year | A3 | A-Class |
|---|---|---|
| 2016 | 88.5% · 128,424 tests | 84.1% · 133,159 tests |
| 2017 | 89.4% · 110,455 tests | 85.8% · 139,570 tests |
| 2018 | 90.4% · 87,091 tests | 88.1% · 134,143 tests |
| 2019 | 90.6% · 67,542 tests | 88.9% · 28,120 tests |
| 2020 | 91.6% · 40,627 tests | 87.3% · 314 tests |
| 2021 | 91.1% · 40,062 tests | 93.0% · 115 tests |
| 2022 | 91.1% · 16,337 tests | — |
| 2023 | 94.4% · 803 tests | — |
Does the pass rate hold at higher mileage?
Pass rate by the mileage recorded at test, pooled across every published year. A car that stays strong past 90,000 miles is doing something right.
| Mileage | A3 | A-Class |
|---|---|---|
| 0–30,000 mi | 93.1% · 114,710 tests | 91.7% · 60,283 tests |
| 30,000–60,000 mi | 89.5% · 322,303 tests | 86.3% · 296,240 tests |
| 60,000–90,000 mi | 83.9% · 346,801 tests | 81.1% · 290,290 tests |
| 90,000–120,000 mi | 79.0% · 296,926 tests | 76.9% · 141,271 tests |
| 120k+ | 75.1% · 372,836 tests | 74.9% · 59,491 tests |
What to check before you buy
Audi A3
- Suspension arm corroded — 3.5% of tests, £35–£85 to put right.
- Linkage ball joint dust cover insecure — 1.5% of tests, £18–£45 to put right.
- The weakest year on record is 2004 at 70.7%; check that generation's MOT history closely.
Mercedes-Benz A-Class
- Linkage ball joint dust cover deteriorated — 1.5% of tests, £18–£45 to put right.
- SRS warning lamp indicates a fault — 1.5% of tests, £3–£12 to put right.
- The weakest year on record is 2000 at 70.6%; check that generation's MOT history closely.
Both columns cover every published year for the model. Pass rates are test-weighted, so a model with more recent tests is not dragged down by its oldest ones. Repair figures are estimates from UK parts data; a garage quote is the only number that matters for a specific car. The same car can be tested in more than one year, so these are test outcomes, not a count of individual vehicles.
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