AC Cobra MOT pass rate & common failures
Across 39 model years and 1,411 tests, the AC Cobra passes its MOT 91.3% of the time. Against all cars of a similar age (24.5% fail rate), the Cobra comes out 15.8pp better. Its most common failure areas are lighting & signalling, brakes and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (5.8%) and brakes (3.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp, registration plates and service brake performance — headlamp alone was recorded 36 times.
Advisories point at the next bill rather than this one: suspension was flagged on 11.1% of tests without failing them.
The trend is improving — the fail rate fell from 7.9% in 2021 to 5.3% in 2025, as the worst-kept examples leave the fleet.
How it compares
By model year
Every Cobra model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 1985 | 31 | 87.1% | 12.9% | Emissions & environmental |
| 1987 | 34 | 94.1% | 5.9% | Lighting & signalling |
| 1988 | 52 | 96.2% | 3.9% | Emissions & environmental |
| 1989 | 59 | 93.2% | 6.8% | Lighting & signalling |
| 1990 | 55 | 96.4% | 3.6% | Lighting & signalling |
| 1993 | 56 | 92.9% | 7.1% | Lighting & signalling |
| 1997 | 51 | 92.2% | 7.8% | Brakes |
| 1998 | 74 | 89.2% | 10.8% | Lighting & signalling |
| 1999 | 50 | 98.0% | 2.0% | Lighting & signalling |
| 2000 | 111 | 89.2% | 10.8% | Lighting & signalling |
| 2001 | 71 | 93.0% | 7.0% | Lighting & signalling |
| 2002 | 52 | 86.5% | 13.5% | Lighting & signalling |
| 2003 | 71 | 95.8% | 4.2% | Lighting & signalling |
| 2004 | 71 | 90.1% | 9.9% | Lighting & signalling |
| 2005 | 85 | 88.2% | 11.8% | Lighting & signalling |
| 2006 | 55 | 85.5% | 14.5% | Lighting & signalling |
| 2007 | 47 | 89.4% | 10.6% | Other defects |
| 2008 | 53 | 96.2% | 3.8% | Lighting & signalling |
| 2009 | 45 | 84.4% | 15.6% | Lighting & signalling |
| 2010 | 35 | 91.4% | 8.6% | Brakes |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.8% | 82 |
| 2 | Brakes | 3.8% | 54 |
| 3 | Emissions & environmental | 2.7% | 38 |
| 4 | Visibility | 1.7% | 24 |
| 5 | Steering | 1.2% | 17 |
| 6 | Suspension | 1.2% | 17 |
| 7 | Other defects | 1.0% | 14 |
| 8 | Body, structure & corrosion | 0.6% | 9 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp | 36 |
| 2 | Registration plates | 28 |
| 3 | Service brake performance | 26 |
| 4 | Headlamp aim | 24 |
| 5 | Non catalyst emissions | 23 |
| 6 | Washers | 21 |
| 7 | Catalyst emissions | 21 |
| 8 | Rbt (sp) | 19 |
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 | 11.1% | 156 |
| 2 | Emissions & environmental | 6.3% | 89 |
| 3 | Tyres | 3.5% | 50 |
| 4 | Steering | 3.5% | 49 |
| 5 | Brakes | 2.8% | 39 |
| 6 | Other defects | 2.4% | 34 |
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 | 1,264 | 8.5% |
| 30-60k | 95 | 6.3% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 305 | 7.9% |
| 2022 | 299 | 10.7% |
| 2023 | 280 | 11.1% |
| 2024 | 261 | 8.1% |
| 2025 | 266 | 5.3% |
What to check before buying a AC Cobra
- Lighting & signalling (5.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (3.8% 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.
- Emissions & environmental (2.7% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 AC Cobra?
91.3% of the 1,411 AC Cobra MOT tests in this dataset passed, an 8.6% fail rate, across model years 1980–2018.
What does the AC Cobra most often fail its MOT on?
Lighting & signalling, recorded in 5.8% of tests, then brakes (3.8%).
Methodology & source. Based on 1,411 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.