Bsa M20 Reliability, MOT Pass Rate & Common Faults
Free Bsa M20 car check
Is the Bsa M20 reliable? We analysed 1,311 real MOT tests across 338 vehicles to find out.
Got a specific Bsa M20? Enter the reg for a free check:
The Bsa M20 is above average for reliability based on real UK MOT data. Common problems include stop lamp does not illuminate immediately a brake applies, horn not working and floor brake test the less effective brake control does not achieve an efficiency of 25%.. Here's everything you need to know before buying a used Bsa M20.
Bsa M20 Number Plates
Number plates registered to a Bsa M20. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Bsa M20 MOT Pass Rate by Year
How likely is a Bsa M20 to pass its MOT? Here's the pass rate for each registration year, newest first.
Bsa M20 Problems — What Goes Wrong?
The most common reasons a Bsa M20 fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Bsa M20 Mileage — What's Normal?
How many miles does a typical Bsa M20 owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Bsa M20 MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Bsa M20 year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 1968 | 68 | 88.2% | 3,826 | 11,960 | 17,577 |
How Long Does a Bsa M20 Last?
Based on 338 Bsa M20 vehicles on UK roads.
Bsa M20 Mileage Distribution
Total mileage recorded across all Bsa M20 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 M20
Based on MOT pass rates across all registration years with sufficient test data.
88.2% MOT pass rate from 68 tests
The best year to buy a used Bsa M20 is 1968, which has the highest MOT pass rate at 88.2% across 68 tests.
How Does the Bsa M20 Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Bsa M20 THIS CAR | 91.6% | 1,311 | 7,489 mi | 58 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 |
| Mercedes C200 CDI Classic SE Auto | 71.5% | 453 | 140,258 mi | — yrs |
Compared to the Bsa A10 (92.2% pass rate) and the Bsa Bantam (89.9% pass rate), the Bsa M20 sits in the middle of the pack on MOT reliability.
Found a Bsa M20 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 M20Should you buy a used Bsa M20?
The Bsa M20 has an overall MOT pass rate of 91.6% across 1,311 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 M20 are stop lamp does not illuminate immediately a brake applies (4 recorded failures), horn not working (4), and floor brake test the less effective brake control does not achieve an efficiency of 25%. (4). 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 M20 owner drives around 194 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 M20 models stay on UK roads for around 58 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.