London Taxis Int Tx4 MOT pass rate & common failures
Across 17 model years and 86,871 tests, the London Taxis Int Tx4 passes its MOT 80.4% of the time. All cars of a similar age fail at 19.8%, so the Tx4 sits squarely on the average. Its most common failure areas are lighting & signalling, suspension and brakes.
Best and worst Tx4 years
Ranked across Tx4 years with at least 1,000 tests. Older cars fail more simply because they are older — compare years close together in age before drawing conclusions.
What the MOT record shows
The strongest year on this record is 2017 (85.9% pass rate); the weakest is 2007 (73.2%). Older cars carry more of the difference than the average implies.
No single area dominates — lighting & signalling (14.2%) and suspension (13.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are pins and bushes, headlamp aim and ball joint — pins and bushes alone was recorded 7,598 times.
Mileage matters less than usual here: the Tx4 fails 24.4% of the time in the 0-30k band and 21.0% at 150k+, a spread of only 3.4 points.
The diesel cars hold up better: 19.5% fail against 26.5% for petrol, a 7.0-point gap across 86,404 tests.
Suspension is the most common advisory, noted on 21.2% of tests — work that passed today but is likely due soon.
How it compares
By model year
Every Tx4 model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2006 | 572 | 72.2% | 27.8% | Lighting & signalling |
| 2007 | 4,704 | 73.2% | 26.8% | Lighting & signalling |
| 2008 | 4,330 | 73.5% | 26.5% | Lighting & signalling |
| 2009 | 5,800 | 75.4% | 24.6% | Suspension |
| 2010 | 7,730 | 76.4% | 23.6% | Suspension |
| 2011 | 8,997 | 77.1% | 22.9% | Suspension |
| 2012 | 6,710 | 81.3% | 18.7% | Suspension |
| 2013 | 6,686 | 82.4% | 17.6% | Lighting & signalling |
| 2014 | 13,727 | 81.2% | 18.8% | Lighting & signalling |
| 2015 | 12,243 | 84.3% | 15.7% | Lighting & signalling |
| 2016 | 9,323 | 85.2% | 14.8% | Lighting & signalling |
| 2017 | 6,039 | 85.9% | 14.1% | Lighting & signalling |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.2% | 12,302 |
| 2 | Suspension | 13.8% | 11,949 |
| 3 | Brakes | 9.3% | 8,073 |
| 4 | Emissions & environmental | 5.5% | 4,794 |
| 5 | Visibility | 4.5% | 3,872 |
| 6 | Steering | 4.4% | 3,817 |
| 7 | Body, structure & corrosion | 3.7% | 3,233 |
| 8 | Tyres | 3.6% | 3,156 |
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 | 7,598 |
| 2 | Headlamp aim | 4,648 |
| 3 | Ball joint | 4,580 |
| 4 | Rbt (sp) | 3,544 |
| 5 | Malfunction indicator lamp | 3,075 |
| 6 | Position lamp | 2,972 |
| 7 | Headlamp | 2,779 |
| 8 | Track rod end | 2,750 |
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 | 21.2% | 18,438 |
| 2 | Brakes | 14.1% | 12,249 |
| 3 | Emissions & environmental | 13.6% | 11,794 |
| 4 | Tyres | 11.1% | 9,622 |
| 5 | Steering | 8.2% | 7,094 |
| 6 | Lighting & signalling | 6.5% | 5,675 |
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 | 955 | 24.4% |
| 30-60k | 1,177 | 12.3% |
| 60-90k | 3,475 | 12.8% |
| 90-120k | 6,731 | 14.4% |
| 120-150k | 10,075 | 15.6% |
| 150k+ | 62,647 | 21.0% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 84,988 | 19.5% |
| Petrol | 1,416 | 26.5% |
| Gas/LPG | 455 | 28.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 21,327 | 19.8% |
| 2022 | 20,574 | 19.9% |
| 2023 | 17,628 | 19.9% |
| 2024 | 14,759 | 19.5% |
| 2025 | 12,583 | 18.5% |
What to check before buying a London Taxis Int Tx4
- Lighting & signalling (14.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (13.8% 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 (9.3% 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
What is the MOT pass rate for the London Taxis Int Tx4?
80.4% of the 86,871 London Taxis Int Tx4 MOT tests in this dataset passed, a 19.6% fail rate, across model years 2001–2017.
What does the London Taxis Int Tx4 most often fail its MOT on?
Lighting & signalling, recorded in 14.2% of tests, then suspension (13.8%).
Which Tx4 years are best and worst for MOT results?
2017 has the best pass rate at 85.9% and 2007 the weakest at 73.2%, from 6,039 and 4,704 tests respectively.
How much does mileage affect Tx4 MOT results?
Fail rates run at 24.4% for cars in the 0-30k band and 21.0% for 150k+, a 3.4-point difference.
Is the diesel or petrol Tx4 more reliable at MOT time?
On MOT-testable defects the diesel fails 19.5% of the time against 26.5% for the petrol. This covers testable items only, not engine or gearbox reliability.
Methodology & source. Based on 86,871 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.