1978 MG Mgb Roadster MOT Pass Rate
Pass rate for Mgb Roadster models manufactured in 1978, based on 44 real MOT test results.
Data from official DVSA MOT testing records
1978 MG Mgb Roadster MOT Analysis
The 1978 MG Mgb Roadster has an MOT pass rate of 79.5% based on 44 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 42,417 miles on the odometer. With a 20.5% failure rate, the 1978 Mgb Roadster is rated as "Excellent" for MOT reliability.
The leading cause of MOT failure for the 1978 MG Mgb Roadster is Brakes, responsible for 6.8% 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. Driver's View of the Road is the second most common issue at 4.5%. Suspension follows at 2.3%.
Top failures specific to 1978 models only. The overall Mgb Roadster page may show different rankings.
What Fails Most
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Brakes | 6.8% | 3 |
| 2 | Driver's View Of The Road | 4.5% | 2 |
| 3 | Suspension | 2.3% | 1 |
Failures per 10,000 Miles
avg. 42,417 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 |
|---|---|---|---|
| Brakes | 1.61 | 6.8% | 3 |
| Visibility | 1.07 | 4.5% | 2 |
| Suspension | 0.54 | 2.3% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1978 MG Mgb Roadster has an MOT pass rate of 79.5% based on 44 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 42,417 miles on the odometer. With a 20.5% failure rate, the 1978 Mgb Roadster is rated as "Excellent" for MOT reliability.
If you own or are considering buying a 1978 MG Mgb Roadster, 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). With relatively low average mileage of 42,417 miles, many of these vehicles are still in good mechanical condition.
Brakes — 6.8% of failures
Brakes issues account for 6.8% of MOT failures on 1978 MG Mgb Roadster 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).
Driver's View of the Road — 4.5% of failures
Driver's View of the Road issues account for 4.5% of MOT failures on 1978 MG Mgb Roadster models. Driver's View of the Road issues are a common cause of MOT failure. Regular inspection and maintenance of these components helps ensure your vehicle passes its MOT. Typical repair costs: £100–400. Pre-MOT check: Have this system checked during regular servicing. Look for warning signs like unusual noises, vibrations, or dashboard warning lights.
Suspension — 2.3% of failures
Suspension issues account for 2.3% of MOT failures on 1978 MG Mgb Roadster models. 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.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.