81.7%
MGB
MGB MOT pass rate and common problems
The MGB passed 81.7% of its initial MOT tests in 2025, 9.4 percentage points above the 72.3% UK average. The item testers recorded most often was position lamp not working.
Checking a specific car? Its own results, advisories and recorded mileages are in a free MOT history check.
How the MGB compares
Initial MOT tests in 2025, retests excluded. A car that failed and was repaired at the test station counts as a fail.
80.9%
MG average
72.3%
UK average, all cars
The MGB runs 0.8 points ahead of the MG average. It is 5th of the 12 MG models in the data. The average MGB arrived at its test 51.4 years old with 43,720 miles recorded.
A pass rate records whether cars met the roadworthiness standard on test day. It is not a reliability score, and part of any gap reflects how old the tested cars were.
MGB MOT pass rate by age
The same 2025 tests split by the car's age at test.
| Age at test | Tests | Pass rate | vs UK average |
|---|---|---|---|
| 3 to 5 years (small sample) | 1 | 100% | 27.7 pts above |
| 6 to 10 years (small sample) | 7 | 100% | 27.7 pts above |
| 11 years and over | 4,490 | 81.7% | 9.4 pts above |
Too few tests fall into some age groups to compare them reliably. The UK average of 72.3% covers cars of every age, so compare like with like.
Where MGB failures cluster
Every failure item recorded on MGB cars in 2025, grouped into the DVSA's test areas.
Lamps, reflectors and electrical equipment and brakes together account for 53.2% of recorded failure items. These are recorded failures across the model, not faults every car has.
The 10 most common MGB MOT failures
Specific items recorded on MGB cars that failed their 2025 MOT, as a share of all recorded failure items.
Together these 10 items make up 38% of everything testers recorded against failed MGB cars. The rest is spread across many smaller items, and one failed test often records several at once.
What to look at on a MGB
The recorded failures above, grouped by area, biggest first.
1
Lamps, reflectors and electrical equipment
Recorded most often: position lamp not working, horn not working, headlamp aim too low, stop lamp all not working and headlamp not working on dipped beam. 16.8% of failure items.
2
Brakes
Recorded most often: service brake imbalance across an axle and service brake performance excessively binding. 7.9% of failure items.
3
Visibility
Recorded most often: washers not working. 5.1% of failure items.
4
Noise, emissions and leaks
Recorded most often: non catalyst emissions emissions carbon monoxide content excessive. 4.3% of failure items.
The car's own MOT history matters more than any model average. A free MOT history check shows whether a specific MGB has failed on these items before, or had them noted as advisories. Buying one? See the used MGB buying guide.
Already found one?
Check its finance, write-off, theft, mileage and keeper history with a £15 vehicle history report.
MGB MOT FAQs
What is the MGB MOT pass rate?
81.7% of MGB cars passed their initial MOT first time in 2025, from 4,498 tests. That is 9.4 percentage points above the 72.3% average for all cars, and ranks 175th of 575 models.
What does a MGB most commonly fail its MOT on?
The item testers recorded most often on MGB cars failing their 2025 MOT was position lamp not working, on 5.6% of failure items. Next were washers not working (5.1%) and service brake imbalance across an axle (4.3%).
Which area causes the most MGB MOT failures?
Across every recorded failure item, the largest area was lamps, reflectors and electrical equipment at 30.9%, followed by brakes at 22.3%.
Does this mean every MGB has these problems?
No. These are the items testers recorded across every MGB that failed in 2025. They show where the model most often needs attention, not the condition of any individual car.
How do I see a specific MGB's MOT history?
Enter its registration on the free Carpeep MOT history check to see that car's own test results, failures, advisories and recorded mileages.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025: class 4 initial tests, retests excluded, with failure items from failed tests (advisories and minor defects excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.