2012 London Taxis Int Tx4 — MOT failures & pass rate
The 2012 London Taxis Int Tx4 passed 81.3% of its 6,710 recorded MOT tests. All cars of a similar age fail 21.3% of the time, so this is 2.6pp better than the group it competes with. Failures cluster in suspension, lighting & signalling and brakes.
What the MOT record shows
No single area dominates — suspension (14.0%) and lighting & signalling (13.9%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are pins and bushes, ball joint and headlamp aim — pins and bushes alone was recorded 550 times.
Mileage matters less than usual here: the 2012 Tx4 fails 21.2% of the time in the 0-30k band and 19.2% at 150k+, a spread of only 2.0 points.
Advisories point at the next bill rather than this one: suspension was flagged on 19.7% of tests without failing them.
The trend is worsening — 17.8% of tests failed in 2021 against 22.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 14.0% | 941 |
| 2 | Lighting & signalling | 13.9% | 935 |
| 3 | Brakes | 9.5% | 635 |
| 4 | Emissions & environmental | 6.0% | 402 |
| 5 | Visibility | 4.4% | 297 |
| 6 | Body, structure & corrosion | 4.1% | 275 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Pins and bushes | 550 |
| 2 | Ball joint | 397 |
| 3 | Headlamp aim | 327 |
| 4 | Rbt (sp) | 278 |
| 5 | Malfunction indicator lamp | 269 |
| 6 | Headlamp | 252 |
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 | 19.7% | 1,320 |
| 2 | Emissions & environmental | 12.1% | 814 |
| 3 | Brakes | 10.6% | 712 |
| 4 | Tyres | 9.5% | 640 |
| 5 | Lighting & signalling | 5.9% | 393 |
| 6 | Steering | 5.8% | 386 |
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 | 33 | 21.2% |
| 60-90k | 82 | 11.0% |
| 90-120k | 169 | 15.4% |
| 120-150k | 440 | 14.3% |
| 150k+ | 5,935 | 19.2% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 6,497 | 18.4% |
| Petrol | 188 | 27.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,551 | 17.8% |
| 2022 | 1,668 | 17.8% |
| 2023 | 1,641 | 17.6% |
| 2024 | 1,012 | 20.5% |
| 2025 | 838 | 22.0% |
What to check before buying a 2012 Tx4
On a 2012 Tx4, suspension is what the MOT record says goes wrong most — it appeared in 14.0% of tests. Check these areas before you commit.
- Suspension (14.0% 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.
- Lighting & signalling (13.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (9.5% 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 2012 London Taxis Int Tx4s pass their MOT?
81.3% of the 6,710 2012 London Taxis Int Tx4 MOT tests in this dataset passed — a 18.7% fail rate.
What is the most common MOT failure on a 2012 London Taxis Int Tx4?
Suspension, recorded in 14.0% of tests, followed by lighting & signalling (13.9%).
Does the 2012 Tx4 get worse with mileage?
Its MOT fail rate rises from 21.2% in the 0-30k band to 19.2% in the 150k+ band.
Methodology & source. Based on 6,710 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.