1991 Mercedes-Benz 230 — MOT failures & pass rate
Across 609 MOT tests, the 1991 Mercedes-Benz 230 recorded a 78.3% pass rate. All cars of a similar age fail at 22.4%, so the 1991 230 sits squarely on the average. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
Lighting & signalling dominates the failure mix at 12.6% of all tests — 4.4 points clear of suspension, so it is the first thing to check.
At component level the recurring items are headlamp aim, rigid brake pipes and position lamp — headlamp aim alone was recorded 35 times.
A 150k+ example is materially riskier than a 60-90k one: 29.3% versus 18.8%.
Advisories point at the next bill rather than this one: brakes was flagged on 36.6% of tests without failing them.
The trend is improving — the fail rate fell from 24.4% in 2021 to 17.8% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 12.6% | 77 |
| 2 | Suspension | 8.2% | 50 |
| 3 | Brakes | 7.9% | 48 |
| 4 | Body, structure & corrosion | 6.7% | 41 |
| 5 | Visibility | 4.4% | 27 |
| 6 | Emissions & environmental | 3.6% | 22 |
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 | 35 |
| 2 | Rigid brake pipes | 32 |
| 3 | Position lamp | 29 |
| 4 | Rear fog lamp | 23 |
| 5 | Component mounting prescribed areas | 22 |
| 6 | Exhaust system | 20 |
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 | 36.6% | 223 |
| 2 | Suspension | 31.0% | 189 |
| 3 | Emissions & environmental | 21.7% | 132 |
| 4 | Tyres | 18.2% | 111 |
| 5 | Body, structure & corrosion | 16.4% | 100 |
| 6 | Other defects | 12.0% | 73 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 60-90k | 85 | 18.8% |
| 90-120k | 134 | 16.4% |
| 120-150k | 122 | 15.6% |
| 150k+ | 229 | 29.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 135 | 24.4% |
| 2022 | 135 | 22.2% |
| 2023 | 128 | 22.7% |
| 2024 | 110 | 20.0% |
| 2025 | 101 | 17.8% |
What to check before buying a 1991 230
On a 1991 230, lighting & signalling is what the MOT record says goes wrong most — it appeared in 12.6% of tests. Check these areas before you commit.
- Lighting & signalling (12.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (8.2% 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.
- Brakes (7.9% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
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 Mercedes-Benz 230s pass their MOT?
78.3% of the 609 1991 Mercedes-Benz 230 MOT tests in this dataset passed — a 21.7% fail rate.
What is the most common MOT failure on a 1991 Mercedes-Benz 230?
Lighting & signalling, recorded in 12.6% of tests, followed by suspension (8.2%).
Does the 1991 230 get worse with mileage?
Its MOT fail rate rises from 18.8% in the 60-90k band to 29.3% in the 150k+ band.
Methodology & source. Based on 609 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.