Triumph Tr3a MOT Pass Rate
Overall pass rate across all manufacture years, based on 489 real MOT test results. Failure rate: 12.7%.
Data from official DVSA MOT testing records
Triumph Tr3a MOT Reliability Overview
The Triumph Tr3a is a rare vehicle in the UK, with 489 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 87.3% and a failure rate of 12.7%, which is well above the UK average of approximately 37%.
Based on this data, the Triumph Tr3a earns a "Excellent" reliability rating. The average Triumph Tr3a presents for MOT with approximately 34,478 miles on the clock. Manufacture year matters: 1961 models achieve the highest pass rate at 88.6%, while 1960 models have the lowest at 86.8%. This 1.8 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Triumph Tr3a is Lamps, Reflectors and Electrical Equipment, affecting 9.0% of all tests. Lighting failures cover all external lights: headlights, tail lights, brake lights, indicators, fog lights, and reflectors. A single blown bulb will cause an MOT fail. This is one of the most preventable failure categories. The second most common issue is Suspension at 6.7%. Brakes rounds out the top three at 6.7%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.
Top failures across all manufacture years combined. Individual year pages may show different top failures.
What Fails Most
Best Year to Buy
📈 How Each Vintage Ages
Pass Rate by Manufacture Year
* High Fail Rate badge indicates an MOT pass rate below 65% (failure rate above 35%).
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Lamps, Reflectors And Electrical Equipment | 10.4% | 51 |
| 2 | Suspension | 8.4% | 41 |
| 3 | Brakes | 7.4% | 36 |
| 4 | Steering | 5.5% | 27 |
| 5 | Driver's View Of The Road | 3.5% | 17 |
| 6 | Tyres | 1.2% | 6 |
| 7 | Visibility | 1.2% | 6 |
| 8 | Exhaust, Fuel And Emissions | 1.0% | 5 |
| 9 | Noise, Emissions And Leaks | 0.6% | 3 |
| 10 | Road Wheels | 0.6% | 3 |
| 11 | Items Not Tested | 0.6% | 3 |
| 12 | Body, Structure And General Items | 0.4% | 2 |
| 13 | Seat Belts And Supplementary Restraint Systems | 0.4% | 2 |
Failures per 10,000 Miles
avg. 34,478 miFor every 10,000 miles driven, this shows what percentage of MOT tests fail for each category. This accounts for how far cars are actually driven, not just raw pass/fail counts.
View as table
| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Lamps & Electrical | 3.03 | 10.4% | 51 |
| Suspension | 2.43 | 8.4% | 41 |
| Brakes | 2.14 | 7.4% | 36 |
| Steering | 1.60 | 5.5% | 27 |
| Visibility | 1.37 | 4.7% | 23 |
| Tyres | 0.36 | 1.2% | 6 |
| Emissions & Exhaust | 0.30 | 1.0% | 5 |
| Noise, emissions and leaks | 0.18 | 0.6% | 3 |
| Wheels | 0.18 | 0.6% | 3 |
| Items Not Tested | 0.18 | 0.6% | 3 |
| Body & Structure | 0.12 | 0.4% | 2 |
| Seat Belts | 0.12 | 0.4% | 2 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Triumph Tr3a has 34,478 miles when tested for MOT.
📊 Mileage-Adjusted Failure Rate
How often this car fails MOT relative to how much it's driven — a fairer comparison than raw pass rate.
The Triumph Tr3a has a mileage-adjusted failure rate of 3.68% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Triumph Tr3a MOT Data
The Triumph Tr3a is a rare vehicle in the UK, with 489 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 87.3% and a failure rate of 12.7%, which is well above the UK average of approximately 37%.
For Triumph Tr3a owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on lamps, reflectors and electrical equipment and suspension for the best chance of a first-time pass. Use our detailed year-by-year breakdown and failure analysis below to understand how your specific Tr3a is likely to perform.
Lamps, Reflectors and Electrical Equipment — 9.0% of failures
Lamps, Reflectors and Electrical Equipment issues account for 9.0% of MOT failures on the Triumph Tr3a. Lighting failures cover all external lights: headlights, tail lights, brake lights, indicators, fog lights, and reflectors. A single blown bulb will cause an MOT fail. This is one of the most preventable failure categories. Typical repair costs: £5–50. Pre-MOT check: Walk around the car and check every light — headlights (dipped and main beam), side lights, tail lights, brake lights, indicators, hazard lights, reverse light, rear fog light, and number plate lights. Replace any blown bulbs before the test.
Suspension — 6.7% of failures
Suspension issues account for 6.7% of MOT failures on the Triumph Tr3a. Suspension failures typically involve worn bushes, leaking shock absorbers, broken coil springs, and damaged suspension arms. These affect ride quality, tyre wear, and road holding. Typical repair costs: £200–500. Pre-MOT check: Look for uneven tyre wear, listen for clunking over bumps, and check if the car pulls to one side. A bouncy ride suggests worn shock absorbers. Visually inspect coil springs for cracks.
Brakes — 6.7% of failures
Brakes issues account for 6.7% of MOT failures on the Triumph Tr3a. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs: £150–400. Pre-MOT check: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm).
Frequently Asked Questions
What is the MOT pass rate for the Triumph Tr3a?
Based on 489 MOT tests in our database, the Triumph Tr3a has an overall pass rate of 87.3% (12.7% fail rate).
What are the most common MOT failures on a Triumph Tr3a?
The top 3 reasons a Triumph Tr3a fails its MOT are: 1. Lamps, Reflectors and Electrical Equipment (9.0%), 2. Suspension (6.7%), 3. Brakes (6.7%). Check these areas before booking your MOT.
Is the Triumph Tr3a reliable?
With a 12.7% MOT failure rate, the Tr3a is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Triumph Tr3a?
Based on failure data, focus on: Lamps, Reflectors and Electrical Equipment (9.0%); Suspension (6.7%); Brakes (6.7%). These are the areas most likely to cause a fail. Also check all lights, tyres (minimum 1.6mm tread), and windscreen condition — these are quick wins that apply to all cars.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.