BMW

BMW 420 (2020)

3,058 real MOT outcomes analysed • 91.3% first-time pass rate

2020 BMW 420

CarHunch analysed 3,058 real MOT records for the 2020 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

The 2020 BMW 420 is significantly more reliable than average, with a 91.3% first-time pass rate well above the UK's 80%, though 18% have encountered a dangerous defect at some point—worth factoring into your decision. Petrol and diesel variants perform similarly (91.7% and 90.4% respectively), so fuel type isn't a differentiator here.

These cars are running relatively light at under 33,000 miles on average for their age, which partly explains the strong pass rate, and they're averaging fewer than 0.4 failures per test. Focus your pre-purchase inspection on the items flagged in advisories—averaging 2.3 per vehicle—as these signal wear points before they become failures; brake fluid condition and suspension components are common culprits on this generation.

The 2020 BMW 420 passes its MOT first time at roughly the UK average rate (91.3%) — solid but worth checking this vehicle's history carefully.

⚠️ 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
91.3%
UK average ~80%
Better than average
Dangerous (ever)
18%
At least once in MOT history
Check this vehicle
Avg failures / car
0.39
Over 3.6 tests on record
Low
Typical mileage
29k
Middle half: 22k–37k
For context
Good baseline reliability. A 91.3% 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 2.3 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 3,058 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.

Average reliability — agree?

What tends to go wrong

Across 3,058 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 2020.

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 3,058 BMW 420 cars.

UK

Before you buy a 2020 BMW 420

Based on MOT data from 3,058 vehicles — here's what to check.

  • 📋 Check the full MOT history. 18% 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 ClickMechanic
  • 📄 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 carVertical Get 20% off via CarHunch

Pass Rate by Fuel Type

Fuel type Vehicles Pass rate Avg failures
Petrol (69%) 2,115 91.7% 0.38
Diesel (31%) 943 90.4% 0.42

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%
34
Yellow 0%
30
Bronze 0%
28

Mileage Distribution

Most 2020 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.

28,697
typical
22,036
low mileage
36,919
high mileage

Half of all 2020 BMW 420 vehicles fall between 22,036 and 36,919 miles.

Is the mileage you're seeing normal?
Under 22,036 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.
22,036–36,919 miles — normal for age. This is where most 2020 BMW 420s sit.
Over 49,840 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2020 BMW 420 — Still on the Road

Almost all 2020 BMW 420s are still on the road.

Strong survival — 2,923 vehicles still getting MOTs in 2025, 97% of the peak.

408 2,923 2022 2025

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2022–2025.

MOT History Averages

3.6
Avg MOT tests per vehicle
0.39
Avg failures per vehicle
2.3
Avg advisories per vehicle
Other model years — BMW 420: All 420 years → Which year to buy? →
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Compare with another model

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Average reliability — agree?