BMW 420i M Sport Auto: MOT pass rate and reliability data

The BMW 420i M Sport Auto passes its MOT first time more often than the average UK car, by 12.9 percentage points. These figures come from the DVSA's full year of anonymised MOT results, covering 3,317 individual BMW 420i M Sport Auto tests. Nothing here is an estimate or a survey.

The numbers

What this means if you are buying one

A 89.6% first-time pass rate means roughly 10 in every 100 BMW 420i M Sport Autos 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 420i M Sport Auto tested had covered 24,153 miles and was built around 2021.

What this means at salvage auction

Pass rate is a proxy for what a car costs to keep on the road. The BMW 420i M Sport Auto sits 12.9 points above the national average, ranked 768 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 420i M Sport Auto 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 420i M Sport Autos at UK salvage auction.

Most common MOT failures on a BMW 420i M Sport Auto

1. A tyre seriously damaged, 6.6% of tests (2.38x the national rate for this defect)
2. Tyre tread depth not in accordance with the requirements, 2.6% of tests
3. A tyre cords visible or damaged, 1.7% of tests
4. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 0.6% of tests
5. Number plate does not conform to the specified requirements, 0.4% of tests (2.29x the national rate for this defect)
6. 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, 0.3% of tests (1.4x the national rate for this defect)
7. Any fracture or welding defect on a wheel, 0.2% of tests (4.11x the national rate for this defect)
8. A wheel with a loose or missing wheel nut, bolt or stud, 0.2% of tests
9. The aim of a headlamp is not within limits laid down in the requirements, 0.2% of tests
10. Wiper blade missing or obviously not clearing the windscreen, 0.2% of tests

From 3,311 DVSA-tracked BMW 420i M Sport Auto tests, 2024. DVSA testers marked 18.27% of these flagged BMW 420i M Sport Auto defects as "dangerous", meaning the tester judged the car unsafe to drive away, against 5.11% nationally.

Most common MOT advisories on a BMW 420i M Sport Auto

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 420i M Sport Auto before it actually fails on it.

1. A seat belt webbing or flexible stalk significantly stretched or weakened, 0.5% of tests (1.42x the national rate for this advisory)
2. Tyre tread depth not in accordance with the requirements, 17.6% of tests, also fails
3. A tyre seriously damaged, 6% of tests, also fails
4. a brake lining or pad worn below 1.5mm, 3.4% of tests
5. A wheel badly distorted or wear between wheel and hub at spigot mounting, 1% of tests
6. Brake disc or drum excessively weakened, insecure or fractured, 0.8% of tests
7. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 0.8% of tests
8. Brake disc or drum significantly and obviously worn, 0.4% of tests
9. A suspension pin, bush or joint excessively worn, 0.3% of tests
10. Number plate inscription missing or illegible, 0.2% of tests

From 3,311 DVSA-tracked BMW 420i M Sport Auto tests, 2024.

BMW 420i M Sport Auto pass rate by model year

Pass rates fall steadily as cars age, so the model year matters as much as the model. First-time pass rate for each BMW 420i M Sport Auto year:

• 2020 BMW 420i M Sport Auto - 92.2% first-time pass, 268 tests
• 2021 BMW 420i M Sport Auto - 89.6% first-time pass, 2,836 tests

Other BMW models

• BMW 3 Series - 76.8%
• BMW 118 - 81.9%
• BMW 116 - 78.6%
• BMW X1 - 85.2%
• BMW X3 - 82.3%
• BMW X5 - 81.2%
• BMW 1 Series - 81.6%
• BMW 520 - 80.2%

Models with a similar pass rate

• Porsche Taycan Turbo S - 89.7%
• Skoda Karoq Sportlne Tdi Scr 4x4 Sa - 89.7%
• Peugeot 2008 GT Line Puretech S/S - 89.6%
• Mercedes-Benz Eqa 250 Amg Line - 89.6%
• Audi Q5 Sport 40 Tdi Mhev Quat S-A - 89.6%
• Land Rover Discovery R-Dynam Hse D Mhev A - 89.6%

If this car is a salvage or write-off

• What does Cat N mean? Category N explained
• What does Cat S mean? Category S explained
• Cat S vs Cat N: the real differences
• Do you need an HPI check on a car you know is a write-off?

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All 2,005 models ranked by MOT pass rate