BMW 420: MOT pass rate and reliability data

The BMW 420 passes its MOT first time more often than the average UK car, by 8.2 percentage points. These figures come from the DVSA's full year of anonymised MOT results, covering 63,149 individual BMW 420 tests. Nothing here is an estimate or a survey.

The numbers

First-time pass rate84.9%
UK national average76.7%
Difference+8.2 points
Tests analysed63,149
Average mileage at test65,764 miles
Average year of manufacture2017
Reliability rank1,244 of 2,005 models

What this means if you are buying one

A 84.9% first-time pass rate means roughly 15 in every 100 BMW 420s presented for MOT fail on the first attempt. That is better than average, so a well-kept example is a reasonably safe used buy. The average BMW 420 tested had covered 65,764 miles and was built around 2017.

What this means at salvage auction

Pass rate is a proxy for what a car costs to keep on the road. The BMW 420 sits 8.2 points above the national average, ranked 1,244 of 2,005 models. On one bought as repairable salvage, the mechanical side is less likely to spring surprises, so your repair estimate should hold up reasonably well.

Before you bid: run the lot through the analyzer, check the car's own record, check the mileage, decode the VIN, and if it carries a marker use the write-off value calculator. Or compare it against another model.

Looking at a specific BMW 420 rather than the model in general? The free check covers its MOT and mileage history, and the full HPI report confirms the insurance write-off category, outstanding finance and whether it is recorded stolen, from licensed data for 5 credits. Already own one that has been damaged? Work out whether fixing it beats selling it with the repair or scrap calculator, and see recorded closing bids for damaged BMW 420s at UK salvage auction.

Most common MOT failures on a BMW 420

  1. Any fracture or welding defect on a wheel, 0.4% of tests (7.62x the national rate for this defect)
  2. A wheel with a loose or missing wheel nut, bolt or stud, 0.7% of tests (2.34x the national rate for this defect)
  3. Number plate does not conform to the specified requirements, 0.4% of tests (2.22x the national rate for this defect)
  4. A tyre has a lump, bulge or tear caused by separation or partial failure of its structure. This includes any lifting of the tread rubber, 0.4% of tests (2.1x the national rate for this defect)
  5. A tyre cords visible or damaged, 3% of tests (1.81x the national rate for this defect)
  6. A tyre seriously damaged, 4.4% of tests (1.57x the national rate for this defect)
  7. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 1.3% of tests (1.36x the national rate for this defect)
  8. Tyre tread depth not in accordance with the requirements, 3.3% of tests
  9. a brake lining or pad worn below 1.5mm, 1.7% of tests
  10. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 1.2% of tests

From 63,105 DVSA-tracked BMW 420 tests, 2024. DVSA testers marked 10.81% of these flagged BMW 420 defects as "dangerous", meaning the tester judged the car unsafe to drive away, against 5.11% nationally.

Most common MOT advisories on a BMW 420

An advisory doesn't fail the car - the tester flags it as worth watching, but it still passes. A different list from the failures above: what testers are noting on a BMW 420 before it actually fails on it.

  1. a brake lining or pad worn below 1.5mm, 11.3% of tests (1.21x the national rate for this advisory), also fails
  2. Tyre tread depth not in accordance with the requirements, 31.6% of tests (1.19x the national rate for this advisory), also fails
  3. Brake disc or drum excessively weakened, insecure or fractured, 9% of tests
  4. A tyre seriously damaged, 6.6% of tests, also fails
  5. A suspension pin, bush or joint excessively worn, 4.2% of tests
  6. Brake disc or drum significantly and obviously worn, 3.6% of tests
  7. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 3% of tests, also fails
  8. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 2.2% of tests
  9. A wheel badly distorted or wear between wheel and hub at spigot mounting, 0.9% of tests
  10. Number plate inscription missing or illegible, 0.9% of tests

From 63,105 DVSA-tracked BMW 420 tests, 2024.

BMW 420 pass rate by model year

From its 2013 to its 2021 model year, the BMW 420's first-time pass rate has risen 11.4 points, from 79.4% to 90.8%, the usual pattern: a newer model year is a younger car today, so it fails less. First-time pass rate for each BMW 420 year:

BMW 420 by fuel type

The BMW 420's two most-tested fuel types split by 2.7 points: diesel passes first time 84.4% of the time (41,928 tests) against 87.1% for petrol (20,942 tests).

Other BMW models

Models with a similar pass rate

If this car is a salvage or write-off

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BMW 420 MOT pass rate badge: 84.9%

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BMW 420 most common MOT failure: Any fracture or welding defect on a wheel (0.4% of tests)

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All 2,005 models ranked by MOT pass rate