BMW 420 Reliability, MOT Pass Rate & Common Faults
Free BMW 420 car check
Is the BMW 420 reliable? We analysed 520,588 real MOT tests across 70,570 vehicles to find out.
Got a specific BMW 420? Enter the reg for a free check:
The BMW 420 is above average for reliability based on real UK MOT data. Here's everything you need to know before buying a used BMW 420.
BMW 420 Number Plates
Number plates registered to a BMW 420. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
BMW 420 MOT Pass Rate by Year
How likely is a BMW 420 to pass its MOT? Here's the pass rate for each registration year, newest first.
BMW 420 Common Faults & Problems
These are the most common serious faults found on BMW 420 models during MOT testing — flagged as dangerous or major failures that need immediate attention.
BMW 420 Mileage — What's Normal?
How many miles does a typical BMW 420 owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
BMW 420 MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the BMW 420 year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 2021 | 959 | 89.6% | 21,788 | 31,008 | 41,529 |
| 2020 | 12,603 | 88.9% | 21,394 | 30,852 | 42,892 |
| 2019 | 39,769 | 87.7% | 24,361 | 35,978 | 50,847 |
| 2018 | 65,816 | 88.1% | 26,783 | 39,991 | 57,010 |
| 2017 | 90,517 | 88.0% | 32,132 | 48,418 | 68,884 |
| 2016 | 101,191 | 86.9% | 36,650 | 55,476 | 79,035 |
| 2015 | 106,055 | 85.6% | 39,080 | 59,194 | 83,887 |
| 2014 | 92,052 | 84.1% | 40,976 | 62,193 | 87,740 |
| 2013 | 7,303 | 83.5% | 45,002 | 68,535 | 97,342 |
How Long Does a BMW 420 Last?
Based on 70,570 BMW 420 vehicles on UK roads.
BMW 420 Mileage Distribution
Total mileage recorded across all BMW 420 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 BMW 420
Based on MOT pass rates across all registration years with sufficient test data.
89.6% MOT pass rate from 959 tests
83.5% MOT pass rate from 7,303 tests
The best year to buy a used BMW 420 is 2021, which has the highest MOT pass rate at 89.6% across 959 tests. The 2013 model year has the lowest pass rate at 83.5% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the BMW 420 Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| BMW 420 THIS CAR | 86.5% | 520,588 | 51,116 mi | 13 yrs |
| BMW 3 Series | 75.1% | 12,840,406 | 90,743 mi | 37 yrs |
| BMW 118 | 81.5% | 1,923,256 | 64,042 mi | 22 yrs |
| BMW X5 | 77% | 1,735,343 | 83,401 mi | 25 yrs |
| Audi Q5 | 86.5% | 932,637 | 60,431 mi | 17 yrs |
Compared to the BMW 3 Series (75.1% pass rate) and the BMW 118 (81.5% pass rate), the BMW 420 outperforms both on MOT reliability.
Found a BMW 420 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 BMW 420Should you buy a used BMW 420?
The BMW 420 has an overall MOT pass rate of 86.5% across 520,588 real MOT tests — comfortably above the UK average, which puts it among the more reliable models on UK roads.
On the safety side, the most frequently flagged dangerous fault is tyre tread depth below requirements of 1.6mm. Dangerous faults cause an immediate MOT failure and mean the vehicle is not roadworthy until repaired. If you're viewing a BMW 420 with an expired or recently passed MOT, ask the seller whether any dangerous faults were found and fixed during the last test.
A typical BMW 420 owner drives around 7,417 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 BMW 420 models stay on UK roads for around 13 years. 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.