Should I check the MOT history before buying a 2021 BMW 420?

Yes. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. A full MOT history analysis will highlight patterns that a single test result won't reveal.

What corrosion should I look for when inspecting a 2021 BMW 420?

Check brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that is expensive to fix and can fail an MOT.

How are tyres and brakes typically on a 2021 BMW 420?

Tyres and brakes are the most common advisory items on vehicles of this age. Budget for replacement if they are near the limit, and factor this into your offer price.

Is the 2021 BMW 420 reliable?

Based on MOT data from 327 vehicles, the 2021 BMW 420 has a first-time MOT pass rate of 92.5%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

What are common problems with the 2021 BMW 420?

The most frequently recorded MOT issues on the 2021 BMW 420 are: Offside Rear Tyre worn close to legal limit/worn on edge (21% of vehicles), Nearside Rear Tyre worn close to legal limit/worn on edge (20.6% of vehicles), Rear Brake pad(s) wearing thin (19.8% of vehicles). These figures are based on actual MOT test records — search a specific registration on CarHunch to see its individual history.

Do I need an HPI check when buying a 2021 BMW 420?

Yes. The MOT history will not show outstanding finance, insurance write-offs, or stolen status. An HPI check covers these areas and should be part of any used car purchase.

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BMW 420 (2021)

327 real MOT outcomes analysed • 92.5% first-time pass rate

2021 BMW 420

CarHunch analysed 327 real MOT records for the 2021 BMW 420. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
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AI Analysis Reliability Overview Common Issues Check a Specific Reg Buyer's Checklist Pass Rate by Fuel Mileage Distribution Still on the Road MOT Averages Colour Breakdown Compare Models

Moderate sample. 327 vehicles on record. Figures are indicative — the specific vehicle's history matters more than these averages.

The 2021 BMW 420 is a reliably built car, with a 92.5% first-time pass rate that sits well above the UK average of 80%, and only 12.2% of vehicles have ever experienced a dangerous defect—a low figure that suggests sound engineering. The petrol engine variants (which make up the vast majority of this cohort) maintain that same 92.5% pass rate, indicating consistent quality across the fuel type.

At 31,009 miles average, these three-year-old BMWs show typical mileage for their age, and the modest failure rate of just 0.25 per vehicle signals that mechanical problems are uncommon when they do come through testing. Focus your pre-purchase inspection on the 1.8 advisories per car on average—these are typically wear items like brake pads and suspension components—and get a full service history check to confirm maintenance has been kept up, as BMW owners who skip services tend to see much worse results at MOT.

The 2021 BMW 420 passes its MOT first time more often than most UK vehicles (92.5% vs ~80% average) — and when it does fail, it's usually something minor and cheap to fix.

⚠️ Around 1 in 8 of these vehicles have had a dangerous MOT failure at some point — usually tyres or brakes, and often a one-off issue rather than a persistent problem. The group stats won't tell you which one you're looking at.

First-time pass

92.5%

UK average ~80%

Better than average

Dangerous (ever)

12.2%

At least once in MOT history

Check this vehicle

Avg failures / car

0.25

Over 2.4 tests on record

Low

Typical mileage

30k

Middle half: 21k–37k

For context

✅ Good baseline reliability. A 92.5% first-time pass rate puts this well above the UK average — it's a well-sorted vehicle in this age bracket.

🔧 Expect consumable spend. An average of 1.8 advisories per vehicle tells you wear items (tyres, brakes) get flagged regularly. Budget for them — they're not surprises.

🔍 The dangerous defect figure is real. Most are one-off tyre failures or brake issues — not structural problems. But it's exactly why checking the individual vehicle's history is essential, not optional.

These stats describe 327 vehicles as a group. The specific vehicle you're looking at could be the one good example or the one outlier. Run its registration to find out.

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What tends to go wrong

Across 327 vehicles — figures show how many had each issue flagged at least once in their MOT history.

Tyre wear 21%

Offside Rear Tyre worn close to legal limit/worn on edge · Nearside Rear Tyre worn close to legal limit/worn on edge · Nearside Front Tyre worn close to legal limit/worn on edge · …

Budget for a full set — on a vehicle this age, tyres are expected consumables. An inspection will confirm how much is left.

Brake wear 19.8%

Rear Brake pad(s) wearing thin · Front Brake pad(s) wearing thin · Front Brake disc worn, pitted or scored, but not seriously weakened · …

Ask the seller when brakes were last serviced. If they don't know, factor in the cost.

Other issues 5.7%

Nearside Rear Child Seat fitted not allowing full inspection of adult belt · Windscreen damaged but not adversely affecting driver's view

Suspension & steering 5.6%

Nearside Rear Shock absorbers has light misting of oil · Offside Rear Shock absorbers has light misting of oil

Harder to spot without a ramp — this is a good reason to book a pre-purchase inspection.

Data covers a 3-year window centred on 2021.

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 327 BMW 420 cars.

Before you buy a 2021 BMW 420

Based on MOT data from 327 vehicles — here's what to check.

📋 Check the full MOT history. 12.2% of these vehicles have had a dangerous defect recorded - recurring advisories often signal problems years before they become failures.
Search the reg on CarHunch for the full MOT history, reliability stats and a free AI-powered analysis of that exact vehicle.
🔍 Brake pipes, sills and subframes are the key areas on a vehicle this age — structural rust is hard to spot without getting underneath. A mechanic will check all of this before you commit, and give you a concrete basis to negotiate on price. Inspection →
📄 Outstanding finance, insurance write-offs and clocking won't appear in the MOT records — a dedicated history check covers all of this. Our link gets you 20% off automatically. History Get 20% off via CarHunch

Pass Rate by Fuel Type

Fuel type	Vehicles	Pass rate	Avg failures
Petrol (96%)	313	92.5%	0.26

Colour Breakdown

Based on 66,334 BMW 420 vehicles registered in the UK — across all years. From DVLA registration records.

Black 26.1%

17,314

White 23.8%

15,781

Blue 21.5%

14,235

Grey 18.8%

12,480

Silver 6.2%

4,131

Red 2.8%

1,854

Orange 0.2%

165

Brown 0.2%

142

Beige 0.2%

140

Green 0.1%

Yellow 0%

Bronze 0%

Mileage Distribution

Most 2021 BMW 420 vehicles sit in the blue band. If the vehicle you're looking at is outside it, it's either unusually low or high mileage for its age.

29,750

typical

20,892

low mileage

37,286

high mileage

Half of all 2021 BMW 420 vehicles fall between 20,892 and 37,286 miles.

Is the mileage you're seeing normal?

✓ Under 20,892 miles — lower than most. Could be great, or could be a vehicle that rarely moved. Check test frequency and mileage progression in the MOT history.

✓ 20,892–37,286 miles — normal for age. This is where most 2021 BMW 420s sit.

⚠ Over 50,336 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2021 BMW 420 — Still on the Road

Almost all 2021 BMW 420s are still on the road.

Strong survival — 317 vehicles still getting MOTs in 2025, 100% of the peak.

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2023–2025.

MOT History Averages

2.4

Avg MOT tests per vehicle

0.25

Avg failures per vehicle

1.8

Avg advisories per vehicle

Other model years — BMW 420: All 420 years → Which year to buy? →

2013 2014 2015 2016 2017 2018 2019 2020

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Compare with another model

See how the 2021 BMW 420 stacks up against a rival.

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