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Pass Your MOT

1981 MG B MOT Pass Rate

Pass rate for B models manufactured in 1981, based on 4,526 real MOT test results.

71.1%
Pass Rate
28.9%
Fail Rate
4,526
Total Tests
51,690
Avg Mileage

Data from official DVSA MOT testing records

This page shows all B cars tested in 1981. Want to see how cars built in 1981 hold up over time?

View 1981 MG B vintage page → (86.4% current pass rate)

1981 MG B MOT Analysis

The 1981 MG B has an MOT pass rate of 71.1% based on 4,526 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 51,690 miles on the odometer. With a 28.9% failure rate, the 1981 B is rated as "Very Good" for MOT reliability.

The leading cause of MOT failure for the 1981 MG B is Lamps, reflectors and electrical equipment, responsible for 0.3% of failures. 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 range from £5–50. Brakes is the second most common issue at 0.2%. Noise, emissions and leaks follows at 0.2%.

Top failures specific to 1981 models only. The overall B page may show different rankings.

What Fails Most

What Fails on This Car?

Click a category to see specific failure items.

View as table
MOT failure categories ranked by failure rate
RankFailure CategoryRate (%)Count
1Lamps, Reflectors And Electrical Equipment0.3%13
2Brakes0.2%11
3Noise, Emissions And Leaks0.2%9
4Body, Chassis, Structure0.2%7
5Visibility0.1%4
6Suspension0.1%3
7Non-component Advisories0.1%3

Failures per 10,000 Miles

avg. 51,690 mi

For 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.

Lamps & Electrical0.06% per 10K miBrakes0.05% per 10K miNoise, emissions and leaks0.04% per 10K miBody & Structure0.03% per 10K miVisibility0.02% per 10K miSuspension0.01% per 10K miNon-component advisories0.01% per 10K mi
View as table
Mileage-normalised failure rates by category
CategoryRate / 10K miRaw %Count
Lamps & Electrical0.060.3%13
Brakes0.050.2%11
Noise, emissions and leaks0.040.2%9
Body & Structure0.030.2%7
Visibility0.020.1%4
Suspension0.010.1%3
Non-component advisories0.010.1%3

Mileage Statistics

51,690
Mean
53,191
Median
31,288
25th Percentile
73,261
75th Percentile
5.59% failures per 10K miles

Mileage-adjusted failure rate — accounts for how much this model year is typically driven.

About This Data

The 1981 MG B has an MOT pass rate of 71.1% based on 4,526 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 51,690 miles on the odometer. With a 28.9% failure rate, the 1981 B is rated as "Very Good" for MOT reliability.

If you own or are considering buying a 1981 MG B, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to lamps, reflectors and electrical equipment: 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. At 51,690 average miles, these vehicles are in the mid-range where component wear starts to become a factor.

Lamps, reflectors and electrical equipment — 0.3% of failures

Lamps, reflectors and electrical equipment issues account for 0.3% of MOT failures on 1981 MG B models. 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.

Brakes — 0.2% of failures

Brakes issues account for 0.2% of MOT failures on 1981 MG B models. 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).

Noise, emissions and leaks — 0.2% of failures

Noise, emissions and leaks issues account for 0.2% of MOT failures on 1981 MG B models. Emissions failures occur when exhaust gases exceed legal limits for carbon monoxide (CO), hydrocarbons (HC), or particulate matter (diesel). Common causes include faulty oxygen sensors, clogged catalytic converters, or DPF issues on diesel vehicles. Typical repair costs: £100–1,000+. Pre-MOT check: If the engine management light is on, get it diagnosed before the MOT. For diesel cars, ensure the DPF has completed a regeneration cycle. Regular servicing and using premium fuel before the test can help.

Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.

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