MG Mgb
From 451 MOT tests. Above average for its class.
Common MOT failure categories
What goes wrong?
The most common MOT failure reasons are windscreen washers not working or not providing sufficient fluid to clear the windscreen, 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., a headlamp or light source missing and inoperative or more than ½ not functioning in the case of led. The top issue, windscreen washers not working or not providing sufficient fluid to clear the windscreen, caused 11 failures in 2024. If you need repairs before retesting, sites like BookMyGarage let you compare local prices.
| windscreen washers not working or not providing sufficient fluid to clear the windscreen | 11 |
| 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. | 6 |
| a headlamp or light source missing, inoperative or more than ½ not functioning in the case of led | 6 |
| actuator leaking and braking performance affected | 6 |
| vehicle structure corroded to the extent that the rigidity of the assembly is seriously reduced | 6 |
| stop lamps all missing or inoperative | 5 |
| audible warning inoperative | 5 |
| steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc | 5 |
| wiper blade missing or obviously not clearing the windscreen | 4 |
| braking effort not recording at a wheel | 3 |
How serious are these failures?
Not all MOT failures are equal. Only 21.1% of Mgb failures are serious (safety or roadside), below the 44.4% average. When this car fails its MOT, it's more likely to be lights, wipers, or emissions than something dangerous. When it does fail, the average repair bill is around £96.
MG Mgb on UK roads
The fleet is shrinking: 151 scrapped or exported in the past year with only 10 newly registered, a net loss of 141.
Quarterly breakdown
| Quarter | On road | SORN | New | Gone | Net |
|---|---|---|---|---|---|
| 2025 Q3 | 24,744 | 12,881 | +3 | -0 | +24 |
| 2025 Q2 | 24,806 | 12,795 | +3 | -0 | +81 |
| 2025 Q1 | 24,891 | 12,629 | +1 | -0 | +204 |
| 2024 Q4 | 25,000 | 12,316 | +3 | -151 | -148 |
| 2024 Q3 | 25,218 | 12,246 | +3 | -93 | -90 |
| 2024 Q2 | 25,234 | 12,320 | +2 | -160 | -158 |
| 2024 Q1 | 25,273 | 12,439 | +2 | -0 | +492 |
| 2023 Q4 | 24,733 | 12,487 | +1 | -0 | +8 |
3 variants on the road
| Variant | Fuel | Licensed | Share |
|---|---|---|---|
| B | Petrol | 13,643 | 55% |
| B Gt | Petrol | 10,371 | 42% |
| B Gt V8 | Petrol | 730 | 3% |
Source: DfT vehicle licensing statistics, 2025 Q3. Crown copyright, OGL v3.0.
Typical mileage
Half of all Mgbs tested had between 16,351 and 62,388 miles on the clock. Relatively low mileage overall. Many are still fairly young.
At 37,197 median miles, the Mgb has 0.037 failures per 10,000 miles driven.
Other MG models
| MG Zs | 81.9% |
| MG 3 | 79.4% |
| MG Zs Exclusive Ev | 89.5% |
| MG Tf | 75% |
| MG Mgf | 72.8% |
Common questions
What is the MG Mgb MOT pass rate?
The MG Mgb has a 86.3% MOT pass rate based on 451 real MOT tests. This is above the national average.
What are common MOT failures on a MG Mgb?
The most common MOT failure on the MG Mgb is windscreen washers not working or not providing sufficient fluid to clear the windscreen, which caused 11 failures. Other common issues include 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..
How many MG Mgbs are on UK roads?
There are 24,744 MG Mgbs currently licensed on UK roads, with 12,881 on SORN.
What is the typical mileage of a MG Mgb at MOT?
The median mileage at MOT for a MG Mgb is 37,197 miles. The middle 50% of vehicles tested have between 16,351 and 62,388 miles.
Buying a used Mgb?
Start with the free tools. Look up the specific vehicle's MOT history on GOV.UK The mileage at each test will show if it's been wound back, and the advisory history tells you what's wearing. Cross-reference that against the typical failures above to see if anything looks unusual for this model.
The free data won't tell you about outstanding finance, theft markers, or write-off history. For that, you need a vehicle history check This is especially important on a private sale where you have fewer legal protections.
Some links are to services we may earn from. Disclosure.
MOT data from DVSA anonymised test results, 2024 test year. Fleet data from DfT vehicle licensing statistics. Crown copyright, OGL v3.0. MOT pass rates are statistical summaries of test outcomes, not assessments of individual vehicle safety or condition. Always inspect a vehicle and check its full MOT history before purchasing. See terms of use.