2005 Smart Forfour — MOT failures & pass rate
4,731 MOT tests on the 2005 Smart Forfour are in this dataset, and 73.5% of them passed. That is 2.8 percentage points better than city cars of a similar age, which fail at 29.3%. Failures cluster in lighting & signalling, brakes and suspension.
What the MOT record shows
Lighting & signalling dominates the failure mix at 21.3% of all tests — 11.6 points clear of brakes, so it is the first thing to check.
At component level the recurring items are headlamp, headlamp aim and wipers — headlamp alone was recorded 528 times.
Mileage is the strongest signal on the record: 20.6% of 0-30k cars fail, rising to 32.7% once past 150k.
Split by fuel, diesel examples fail 4.2pp more often than petrol ones (29.9% vs 25.7%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: suspension was flagged on 33.5% of tests without failing them.
The trend is improving — the fail rate fell from 27.5% in 2021 to 25.4% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 21.3% | 1,010 |
| 2 | Brakes | 9.7% | 459 |
| 3 | Suspension | 9.7% | 458 |
| 4 | Body, structure & corrosion | 6.8% | 321 |
| 5 | Visibility | 6.7% | 318 |
| 6 | Tyres | 4.7% | 220 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp | 528 |
| 2 | Headlamp aim | 486 |
| 3 | Wipers | 251 |
| 4 | Stop lamp | 217 |
| 5 | Position lamp | 216 |
| 6 | Rbt (sp) | 183 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 33.5% | 1,586 |
| 2 | Brakes | 29.0% | 1,371 |
| 3 | Lighting & signalling | 26.8% | 1,270 |
| 4 | Tyres | 26.0% | 1,232 |
| 5 | Other defects | 12.4% | 587 |
| 6 | Body, structure & corrosion | 9.2% | 436 |
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 | 102 | 20.6% |
| 30-60k | 650 | 19.2% |
| 60-90k | 1,385 | 24.6% |
| 90-120k | 1,410 | 27.7% |
| 120-150k | 832 | 31.5% |
| 150k+ | 321 | 32.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 3,842 | 25.7% |
| Diesel | 889 | 29.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,338 | 27.5% |
| 2022 | 1,127 | 25.9% |
| 2023 | 959 | 27.7% |
| 2024 | 721 | 25.0% |
| 2025 | 586 | 25.4% |
What to check before buying a 2005 Forfour
On a 2005 Forfour, lighting & signalling is what the MOT record says goes wrong most — it appeared in 21.3% of tests. Check these areas before you commit.
- Lighting & signalling (21.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (9.7% 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.
- Suspension (9.7% 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
How many 2005 Smart Forfours pass their MOT?
73.5% of the 4,731 2005 Smart Forfour MOT tests in this dataset passed — a 26.5% fail rate.
What is the most common MOT failure on a 2005 Smart Forfour?
Lighting & signalling, recorded in 21.3% of tests, followed by brakes (9.7%).
Does the 2005 Forfour get worse with mileage?
Its MOT fail rate rises from 20.6% in the 0-30k band to 32.7% in the 150k+ band.
Methodology & source. Based on 4,731 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.