Bsa B40 Reliability, MOT Pass Rate & Common Faults
Free Bsa B40 car check
Is the Bsa B40 reliable? We analysed 3,385 real MOT tests across 673 vehicles to find out.
Got a specific Bsa B40? Enter the reg for a free check:
The Bsa B40 is above average for reliability based on real UK MOT data. Common problems include steering headbearing has excessive free play, stop lamp does not illuminate immediately a brake applies and headlamp at least one does not illuminate on dipped beam. Here's everything you need to know before buying a used Bsa B40.
Bsa B40 Number Plates
Number plates registered to a Bsa B40. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Bsa B40 MOT Pass Rate by Year
How likely is a Bsa B40 to pass its MOT? Here's the pass rate for each registration year, newest first.
Bsa B40 Problems — What Goes Wrong?
The most common reasons a Bsa B40 fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Bsa B40 Mileage — What's Normal?
How many miles does a typical Bsa B40 owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Bsa B40 MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Bsa B40 year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 2001 | 65 | 90.8% | 336 | 4,730 | 10,997 |
| 1997 | 53 | 98.1% | 610 | 1,302 | 7,987 |
| 1991 | 56 | 85.7% | 3,894 | 17,650 | 27,905 |
| 1984 | 81 | 90.1% | 3,173 | 4,159 | 13,191 |
| 1983 | 89 | 92.1% | 3,424 | 6,166 | 23,448 |
| 1982 | 76 | 97.4% | 767 | 7,396 | 21,878 |
| 1977 | 54 | 94.4% | 2,623 | 8,454 | 14,954 |
| 1976 | 127 | 91.3% | 1,691 | 3,870 | 9,848 |
| 1975 | 89 | 89.9% | 5,671 | 8,851 | 35,107 |
| 1970 | 52 | 88.5% | 4,737 | 6,567 | 25,462 |
| 1967 | 129 | 95.3% | 1,923 | 5,775 | 9,679 |
| 1965 | 502 | 90.6% | 4,314 | 14,172 | 25,454 |
| 1964 | 163 | 92.6% | 2,213 | 16,855 | 28,099 |
| 1963 | 81 | 95.1% | 5,962 | 17,982 | 31,349 |
| 1962 | 221 | 86.9% | 2,614 | 10,496 | 24,779 |
| 1961 | 466 | 92.1% | 2,818 | 12,561 | 27,488 |
How Long Does a Bsa B40 Last?
Based on 673 Bsa B40 vehicles on UK roads.
Bsa B40 Mileage Distribution
Total mileage recorded across all Bsa B40 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 Bsa B40
Based on MOT pass rates across all registration years with sufficient test data.
98.1% MOT pass rate from 53 tests
85.7% MOT pass rate from 56 tests
The best year to buy a used Bsa B40 is 1997, which has the highest MOT pass rate at 98.1% across 53 tests. The 1991 model year has the lowest pass rate at 85.7% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the Bsa B40 Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Bsa B40 THIS CAR | 91.6% | 3,385 | 8,040 mi | 65 yrs |
| Bsa A10 | 92.2% | 10,105 | 12,338 mi | 74 yrs |
| Bsa Bantam | 89.9% | 7,723 | 13,212 mi | 77 yrs |
| Bsa C15 | 90.2% | 6,096 | 14,541 mi | 67 yrs |
| Mazda MX5 | 75.6% | 3,499 | 96,594 mi | 36 yrs |
Compared to the Bsa A10 (92.2% pass rate) and the Bsa Bantam (89.9% pass rate), the Bsa B40 sits in the middle of the pack on MOT reliability.
Found a Bsa B40 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 Bsa B40Should you buy a used Bsa B40?
The Bsa B40 has an overall MOT pass rate of 91.6% across 3,385 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 Bsa B40 are steering headbearing has excessive free play (19 recorded failures), stop lamp does not illuminate immediately a brake applies (12), and headlamp at least one does not illuminate on dipped beam (11). 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 Bsa B40 owner drives around 127 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 Bsa B40 models stay on UK roads for around 65 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.