MG B MOT Pass Rate
Overall pass rate across all manufacture years, based on 113,630 real MOT test results. Failure rate: 26.7%.
Data from official DVSA MOT testing records
MG B MOT Reliability Overview
The MG B is a well-known vehicle in the UK, with 113,630 MOT test results recorded in our database spanning 33 manufacture years. It has an overall MOT pass rate of 73.3% and a failure rate of 26.7%, which is above the UK average of approximately 37%.
Based on this data, the MG B earns a "Very Good" reliability rating. The average MG B presents for MOT with approximately 43,216 miles on the clock. Manufacture year matters: 1995 models achieve the highest pass rate at 89.4%, while 1987 models have the lowest at 54.7%. This 34.7 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the MG B is Brakes, affecting 18.7% of all tests. 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. The second most common issue is Lamps, Reflectors and Electrical Equipment at 18.4%. Suspension rounds out the top three at 17.4%. 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
Tracking how each manufacture year's MOT pass rate changes as the car ages. Showing 19 vintages — click year chips to highlight.
Multi-line chart showing how different MG B vintages degrade over time, from age 3 to 58 years.
Only vintages with 100+ tests in at least 3 different test years are shown. Fleet average is the UK-wide pass rate for all cars at each age.
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 | 27.2% | 30,995 |
| 2 | Brakes | 22.9% | 26,003 |
| 3 | Suspension | 22.8% | 25,943 |
| 4 | Driver's View Of The Road | 7.6% | 8,653 |
| 5 | Steering | 7.1% | 8,060 |
| 6 | Exhaust, Fuel And Emissions | 7.0% | 7,904 |
| 7 | Tyres | 3.9% | 4,428 |
| 8 | Body, Structure And General Items | 3.4% | 3,858 |
| 9 | Seat Belts And Supplementary Restraint Systems | 2.2% | 2,476 |
| 10 | Noise, Emissions And Leaks | 1.6% | 1,874 |
| 11 | Visibility | 1.3% | 1,526 |
| 12 | Body, Chassis, Structure | 1.2% | 1,324 |
| 13 | Road Wheels | 1.1% | 1,299 |
| 14 | Non-component Advisories | 0.9% | 971 |
Failures per 10,000 Miles
avg. 43,216 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 | 6.32 | 27.2% | 30,995 |
| Brakes | 5.30 | 22.9% | 26,003 |
| Suspension | 5.28 | 22.8% | 25,943 |
| Visibility | 2.07 | 8.9% | 10,179 |
| Steering | 1.64 | 7.1% | 8,060 |
| Emissions & Exhaust | 1.61 | 7.0% | 7,904 |
| Body & Structure | 1.06 | 4.6% | 5,182 |
| Tyres | 0.90 | 3.9% | 4,428 |
| Seat Belts | 0.50 | 2.2% | 2,476 |
| Noise, emissions and leaks | 0.38 | 1.6% | 1,874 |
| Wheels | 0.26 | 1.1% | 1,299 |
| Non-component advisories | 0.20 | 0.9% | 971 |
🚗 Similar Cars to Consider
Mileage at MOT
The average MG B has 43,216 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 MG B has a mileage-adjusted failure rate of 6.18% per 10,000 miles driven. The average across all makes is 5.38%, so this model is worse than average.
About MG B MOT Data
The MG B is a well-known vehicle in the UK, with 113,630 MOT test results recorded in our database spanning 33 manufacture years. It has an overall MOT pass rate of 73.3% and a failure rate of 26.7%, which is above the UK average of approximately 37%.
For MG B owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on brakes and lamps, reflectors and electrical equipment 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 B is likely to perform.
Brakes — 18.7% of failures
Brakes issues account for 18.7% of MOT failures on the MG B. 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).
Lamps, Reflectors and Electrical Equipment — 18.4% of failures
Lamps, Reflectors and Electrical Equipment issues account for 18.4% of MOT failures on the MG B. 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 — 17.4% of failures
Suspension issues account for 17.4% of MOT failures on the MG B. 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.
Frequently Asked Questions
What is the MOT pass rate for the MG B?
Based on 113,630 MOT tests in our database, the MG B has an overall pass rate of 73.3% (26.7% fail rate).
What are the most common MOT failures on a MG B?
The top 3 reasons a MG B fails its MOT are: 1. Brakes (18.7%), 2. Lamps, Reflectors and Electrical Equipment (18.4%), 3. Suspension (17.4%). Check these areas before booking your MOT.
Is the MG B reliable?
With a 26.7% MOT failure rate, the B is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my MG B?
Based on failure data, focus on: Brakes (18.7%); Lamps, Reflectors and Electrical Equipment (18.4%); Suspension (17.4%). 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.