Alfa Romeo 166 MOT pass rate & common failures
The Alfa Romeo 166 appears in 1,430 MOT tests spanning model years 1998–2020, and 71.1% of them passed. Against all cars of a similar age (27.1% fail rate), the 166 comes out 1.8pp worse. Its most common failure areas are lighting & signalling, brakes and suspension.
What the MOT record shows
No single area dominates — lighting & signalling (15.2%) and brakes (13.9%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are position lamp, rbt (sp) and headlamp aim — position lamp alone was recorded 113 times.
Condition tracks the odometer closely. Failures run at 24.6% in the 30-60k band and 34.3% in the 150k+ band, a 9.7-point spread.
Suspension is the most common advisory, noted on 32.7% of tests — work that passed today but is likely due soon.
The trend is worsening — 27.9% of tests failed in 2021 against 33.5% in 2025, the usual pattern as a fleet ages.
How it compares
By model year
Every 166 model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 1999 | 148 | 68.9% | 31.1% | Brakes |
| 2000 | 234 | 67.1% | 32.9% | Lighting & signalling |
| 2001 | 213 | 75.1% | 24.9% | Lighting & signalling |
| 2002 | 167 | 71.9% | 28.1% | Lighting & signalling |
| 2003 | 121 | 70.3% | 29.8% | Brakes |
| 2004 | 235 | 71.9% | 28.1% | Brakes |
| 2005 | 254 | 71.7% | 28.3% | Brakes |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 15.2% | 217 |
| 2 | Brakes | 13.9% | 199 |
| 3 | Suspension | 10.4% | 149 |
| 4 | Body, structure & corrosion | 7.8% | 112 |
| 5 | Emissions & environmental | 6.4% | 91 |
| 6 | Visibility | 5.9% | 84 |
| 7 | Tyres | 4.3% | 61 |
| 8 | Seat belts & restraints | 3.1% | 44 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Position lamp | 113 |
| 2 | Rbt (sp) | 96 |
| 3 | Headlamp aim | 93 |
| 4 | Rigid brake pipes | 85 |
| 5 | Pins and bushes | 73 |
| 6 | Service brake performance | 71 |
| 7 | Joints | 64 |
| 8 | Catalyst emissions | 62 |
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 | 32.7% | 468 |
| 2 | Brakes | 32.5% | 465 |
| 3 | Tyres | 22.7% | 325 |
| 4 | Body, structure & corrosion | 18.9% | 270 |
| 5 | Emissions & environmental | 15.4% | 221 |
| 6 | Other defects | 12.3% | 176 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 114 | 24.6% |
| 60-90k | 380 | 26.6% |
| 90-120k | 436 | 27.8% |
| 120-150k | 280 | 31.8% |
| 150k+ | 175 | 34.3% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 362 | 27.9% |
| 2022 | 329 | 30.4% |
| 2023 | 268 | 25.4% |
| 2024 | 244 | 27.9% |
| 2025 | 227 | 33.5% |
What to check before buying a Alfa Romeo 166
- Lighting & signalling (15.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (13.9% 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.
- Suspension (10.4% 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 Alfa Romeo 166?
71.1% of the 1,430 Alfa Romeo 166 MOT tests in this dataset passed, a 28.9% fail rate, across model years 1998–2020.
What does the Alfa Romeo 166 most often fail its MOT on?
Lighting & signalling, recorded in 15.2% of tests, then brakes (13.9%).
How much does mileage affect 166 MOT results?
Fail rates run at 24.6% for cars in the 30-60k band and 34.3% for 150k+, a 9.7-point difference.
Methodology & source. Based on 1,430 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.