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1978 MG Mgbgt MOT Pass Rate

Pass rate for Mgbgt models manufactured in 1978, based on 113 real MOT test results.

74.3%
Pass Rate
25.7%
Fail Rate
113
Total Tests
69,394
Avg Mileage

Data from official DVSA MOT testing records

1978 MG Mgbgt MOT Analysis

The 1978 MG Mgbgt has an MOT pass rate of 74.3% based on 113 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 69,394 miles on the odometer. With a 25.7% failure rate, the 1978 Mgbgt is rated as "Very Good" for MOT reliability.

The leading cause of MOT failure for the 1978 MG Mgbgt is Brakes, responsible for 1.8% of failures. 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 range from £150–400. Noise, emissions and leaks is the second most common issue at 0.9%. Steering follows at 0.9%.

Top failures specific to 1978 models only. The overall Mgbgt 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
1Brakes1.8%2
2Noise, Emissions And Leaks0.9%1
3Steering0.9%1

Failures per 10,000 Miles

avg. 69,394 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.

Brakes0.26% per 10K miNoise, emissions and leaks0.13% per 10K miSteering0.13% per 10K mi
View as table
Mileage-normalised failure rates by category
CategoryRate / 10K miRaw %Count
Brakes0.261.8%2
Noise, emissions and leaks0.130.9%1
Steering0.130.9%1

Mileage Statistics

69,394
Mean
88,280
Median
77,578
25th Percentile
93,794
75th Percentile
3.70% failures per 10K miles

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

About This Data

The 1978 MG Mgbgt has an MOT pass rate of 74.3% based on 113 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 69,394 miles on the odometer. With a 25.7% failure rate, the 1978 Mgbgt is rated as "Very Good" for MOT reliability.

If you own or are considering buying a 1978 MG Mgbgt, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to brakes: 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). At 69,394 average miles, these vehicles are in the mid-range where component wear starts to become a factor.

Brakes — 1.8% of failures

Brakes issues account for 1.8% of MOT failures on 1978 MG Mgbgt 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 — 0.9% of failures

Noise, emissions and leaks issues account for 0.9% of MOT failures on 1978 MG Mgbgt 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.

Steering — 0.9% of failures

Steering issues account for 0.9% of MOT failures on 1978 MG Mgbgt models. Steering failures include excessive play in the steering wheel, leaking power steering fluid, worn track rod ends, and damaged steering rack. These affect vehicle control and are closely related to suspension wear. Typical repair costs: £150–600. Pre-MOT check: Check for excessive steering wheel play (more than a few inches of free movement). Listen for whining from the power steering pump. Look for fluid leaks under the car near the front wheels.

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

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