MG B Roadster Reliability, MOT Pass Rate & Common Faults
Free MG B Roadster car check
Is the MG B Roadster reliable? We analysed 3,612 real MOT tests across 302 vehicles to find out.
Got a specific MG B Roadster? Enter the reg for a free check:
The MG B Roadster is above average for reliability based on real UK MOT data. Common problems include windscreen washer provides insufficient washer liquid, brake binding and suspension spring mounting prescribed area is excessively corroded. Here's everything you need to know before buying a used MG B Roadster.
MG B Roadster Number Plates
Number plates registered to a MG B Roadster. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
MG B Roadster MOT Pass Rate by Year
How likely is a MG B Roadster to pass its MOT? Here's the pass rate for each registration year, newest first.
MG B Roadster Problems — What Goes Wrong?
The most common reasons a MG B Roadster fails its MOT, ranked by how often they occur. Check for these problems before you buy.
MG B Roadster Mileage — What's Normal?
How many miles does a typical MG B Roadster owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
MG B Roadster MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the MG B Roadster year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 1981 | 107 | 81.3% | 18,843 | 47,445 | 76,894 |
| 1980 | 183 | 76.0% | 13,528 | 36,491 | 60,653 |
| 1979 | 146 | 76.7% | 22,309 | 29,546 | 41,626 |
| 1978 | 272 | 71.7% | 15,518 | 48,731 | 76,266 |
| 1977 | 206 | 74.3% | 42,746 | 56,306 | 79,446 |
| 1976 | 130 | 74.6% | 15,592 | 34,616 | 68,997 |
| 1975 | 125 | 77.6% | 18,838 | 24,622 | 39,229 |
| 1974 | 208 | 76.0% | 11,963 | 24,235 | 75,046 |
| 1973 | 173 | 80.3% | 9,651 | 24,068 | 78,059 |
| 1972 | 358 | 76.8% | 15,330 | 22,097 | 42,633 |
| 1971 | 327 | 74.9% | 21,721 | 58,027 | 80,346 |
| 1970 | 214 | 86.9% | 18,447 | 32,695 | 43,353 |
| 1969 | 221 | 81.0% | 29,136 | 38,115 | 78,925 |
| 1968 | 103 | 83.5% | 18,000 | 43,392 | 47,698 |
| 1967 | 140 | 79.3% | 9,904 | 24,058 | 39,543 |
| 1966 | 82 | 75.6% | 4,430 | 9,470 | 45,229 |
| 1965 | 161 | 79.5% | 19,343 | 34,735 | 45,038 |
| 1963 | 79 | 87.3% | 20,656 | 33,948 | 42,072 |
How Long Does a MG B Roadster Last?
Based on 302 MG B Roadster vehicles on UK roads.
MG B Roadster Mileage Distribution
Total mileage recorded across all MG B Roadster MOT tests. If the car you're looking at is above the 75th percentile, it's done more miles than most.
Best Year to Buy a Used MG B Roadster
Based on MOT pass rates across all registration years with sufficient test data.
87.3% MOT pass rate from 79 tests
71.7% MOT pass rate from 272 tests
The best year to buy a used MG B Roadster is 1963, which has the highest MOT pass rate at 87.3% across 79 tests. The 1978 model year has the lowest pass rate at 71.7% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the MG B Roadster Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| MG B Roadster THIS CAR | 78.0% | 3,612 | 34,822 mi | 63 yrs |
| MG Zr | 69.8% | 651,705 | 57,257 mi | 25 yrs |
| MG Mgf | 66.7% | 546,238 | 62,469 mi | 31 yrs |
| MG Tf | 72.8% | 475,348 | 45,249 mi | 24 yrs |
| Bullit Hero 125 | 76.2% | 1,478 | 3,238 mi | — yrs |
Compared to the MG Zr (69.8% pass rate) and the MG Mgf (66.7% pass rate), the MG B Roadster outperforms both on MOT reliability.
Found a MG B Roadster you like?
Run a full vehicle history check on the specific car. See finance, stolen, write-off, mileage and MOT data for that exact vehicle.
Check a specific MG B RoadsterShould you buy a used MG B Roadster?
The MG B Roadster has an overall MOT pass rate of 78.0% across 3,612 real MOT tests — comfortably above the UK average, which puts it among the more reliable models on UK roads.
The most common problems on the MG B Roadster are windscreen washer provides insufficient washer liquid (81 recorded failures), brake binding (75), and suspension spring mounting prescribed area is excessively corroded (65). These are the faults most likely to cause an MOT failure on this model, so check for them carefully on any test drive or pre-purchase inspection. Many are wear-and-tear items that can be budgeted for, but a car that's already failing on multiple fronts may signal neglected maintenance.
A typical MG B Roadster owner drives around 401 miles per year. If the car you're looking at is significantly above this, expect more wear on suspension, brakes and tyres. If it's well below, the vehicle may have been sitting unused — check for perished rubber, corroded discs and stale fluids.
In terms of longevity, most MG B Roadster models stay on UK roads for around 63 years — a strong showing that suggests solid build quality and readily available parts. If you're buying one that's already approaching that window, the data suggests it has plenty of life left provided it's been maintained.
Before committing to a purchase, we recommend running a full vehicle history check on the specific car. This will reveal any outstanding finance, stolen markers, write-off history and mileage discrepancies that the seller may not disclose — and that the MOT data alone can't tell you.