Mg B - 1977
132.9 faults per 100 tests
Year average for all cars of 1977 is 108.5 faults per 100 tests
Dataset: MOT tests in Great Britain (period: 2024-01-01 to 2025-09-10) for Mg B, model year 1977.
Sample size: 236 cars, 404 tests and 537 recorded faults.
0%
More faults compared to the average car of same model year
More faults compared to the average car of same model year
Quick summary
Total: 236 cars
The 1977 MG B has an overall defect rate of 133 per 100 vehicles, which is 22.5% higher than the average for cars of the same year, rated at 109 per 100. Notably, this model shows significant issues with brakes, visibility, equipment, and other categories, scoring worse than average in each, particularly with brakes where 51% of vehicles failed compared to 40% for the average car. The defect rate tends to increase with mileage, especially in the lower mileage categories, indicating that older models may be more prone to issues earlier in their lifecycle. Despite tyre wear being a common concern, the standout defects in the MG B are more specific to safety and equipment reliability.
Cars by mileage segment
Total: 236 cars
Categories
Brakes
▼ 27.5% worse
51.5 faults / 100 tests
Year avg: 40.4 / 100 tests
- Brake pipe damaged or excessively corroded
- Significant brake effort recorded with no brake applied indicating a binding brake
- Brakes imbalance across an axle such that: the braking effort from any wheel is less than 70% of the maximum effort recorded from the other wheel on the same axle. Or in the case of testing on the road, the vehicle deviates excessively from a straight lin
- Brake disc or drum: insecure, fractured or otherwise likely to fail
- Significant brake effort recorded with no brake applied indicating a binding brake
Steering
▼ 18.5% worse
17.3 faults / 100 tests
Year avg: 14.6 / 100 tests
- Steering rack gaiter or ball joint dust cover: damaged or deteriorated
- A steering ball joint: with excessive wear or free play
- A steering linkage component with: relative movement between components which should be fixed
- Steering rack gaiter or ball joint dust cover: missing or no longer prevents the ingress of dirt etc.
- A steering linkage component: with an unsafe modification
Visibility
▼ 28.7% worse
13.9 faults / 100 tests
Year avg: 10.8 / 100 tests
- Windscreen washers not working or not providing sufficient fluid to clear the windscreen
- Windscreen or window damaged or seriously discoloured: but not adversely affecting driver’s view
- Wiper not operating or missing
- Windscreen washers not working or not providing sufficient fluid to clear the windscreen
- Wiper blade: missing or obviously not clearing the windscreen
Lights & Electrics
▼ 14.7% worse
31.2 faults / 100 tests
Year avg: 27.2 / 100 tests
- A headlamp: missing, inoperative or more than ½ not functioning in the case of LED
- Product on the lens or light source which obviously reduces light intensity or changes emitted colour to other than white or yellow
- The aim of a headlamp is not within limits laid down in the requirements
- Lamp: missing, inoperative or in the case of a multiple light source more than a half not functioning
- A rear registration plate lamp or light source missing or inoperative: when rear registration plate has 2 or more lamps or light sources
Wheels & Suspension
▼ 15.7% worse
78.2 faults / 100 tests
Year avg: 67.6 / 100 tests
- A suspension pin, bush, joint or bearing: excessively worn
- A spring: or spring component fractured or seriously weakened
- A shock absorber damaged … or showing signs of severe leakage
- A wheel bearing: with excessive play
- A tyre: with a lump, bulge or tear … or with cords exposed or damaged
Body/Structure
▼ 9.3% worse
12.9 faults / 100 tests
Year avg: 11.8 / 100 tests
- A floor: excessively deteriorated or insecure
- A transmission: joint, belt or chain excessively worn
- Exhaust system has a major leak or is insecure
- Exhaust system has a major leak or is insecure
- Vehicle structure corroded to the extent that: the rigidity of the assembly is significantly reduced
Equipment
▼ 30.6% worse
6.4 faults / 100 tests
Year avg: 4.9 / 100 tests
- Audible warning:
- Audible warning:
- A seat belt: webbing or flexible stalk significantly stretched or weakened
- The strength or continuity of the load bearing structure within 30cm of any seat belt anchorage (a ’prescribed area’): anchorage likely to become detached in the event of a collision
- Seat belt retractor not functioning as intended
Other
▼ 37.3% worse
54.5 faults / 100 tests
Year avg: 39.7 / 100 tests
- Emissions levels exceed default limits
- Emissions levels exceed default limits
- Fluid: leaking excessively and likely to harm the environment or to pose a safety risk to other road users
- Exhaust noise levels in excess of those permitted
- Exhaust emits excessive dense blue or clearly visible black smoke during acceleration which would obscure the view of other road users
Fault rate by mileage segment
Model
Year average
* Metric: faults per 100 tests.
Most common faults (Top 10)
Fluid: leaking excessively and likely to harm the environment or to pose a safety risk to other road users
ADVISORY
Occurrences: 72
A suspension pin, bush, joint or bearing: excessively worn
ADVISORY
Occurrences: 36
Emissions levels exceed default limits
FAIL
Occurrences: 32
A wheel bearing: with excessive play
ADVISORY
Occurrences: 31
Brake pipe damaged or excessively corroded
ADVISORY
Occurrences: 22
Steering rack gaiter or ball joint dust cover: damaged or deteriorated
MINOR
Occurrences: 18
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
FAIL
Occurrences: 16
A spring: or spring component fractured or seriously weakened
ADVISORY
Occurrences: 16
A tyre: with a lump, bulge or tear … or with cords exposed or damaged
ADVISORY
Occurrences: 13
Brake disc or drum: insecure, fractured or otherwise likely to fail
ADVISORY
Occurrences: 11
Serious faults (Top 10)
Emissions levels exceed default limits
FAIL
Occurrences: 32
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
FAIL
Occurrences: 16
Steering rack gaiter or ball joint dust cover: missing or no longer prevents the ingress of dirt etc.
FAIL
Occurrences: 10
Significant brake effort recorded with no brake applied indicating a binding brake
FAIL
Occurrences: 9
The strength or continuity of the load bearing structure within 30cm … is significantly reduced or inadequately repaired
FAIL
Occurrences: 9
The aim of a headlamp is not within limits laid down in the requirements
FAIL
Occurrences: 9
Brakes imbalance across an axle such that: the braking effort from any wheel is less than 70% of the maximum effort recorded from the other wheel on the same axle. Or in the case of testing on the road, the vehicle deviates excessively from a straight lin
FAIL
Occurrences: 8
A headlamp: missing, inoperative or more than ½ not functioning in the case of LED
FAIL
Occurrences: 7
A tyre: with a lump, bulge or tear … or with cords exposed or damaged
FAIL
Occurrences: 6
Lamp: missing, inoperative or in the case of a multiple light source more than a half not functioning
FAIL
Occurrences: 5