BMW

BMW 420 (2017)

12,164 real MOT outcomes analysed • 89.8% first-time pass rate

2017 BMW 420

CarHunch analysed 12,164 real MOT records for the 2017 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 2017 BMW 420 passes its MOT first time in 89.8% of cases, comfortably ahead of the UK average of 80%, and both diesel and petrol variants perform similarly well (89.5% and 90.5% respectively). However, one in three of these cars has recorded a dangerous defect at some point, which is a material concern for a used buyer and suggests some have experienced significant mechanical issues.

At 51,000 miles median mileage, these are lightly-run examples for their age, yet they're still averaging 0.8 failures and 5.6 advisories per test, indicating wear and minor issues are creeping in. Before committing to purchase, have a pre-buy inspection focus on the cooling system and suspension components, as these typically drive the advisory count on this model.

The 2017 BMW 420 has a decent first-time pass rate (89.8%), but a higher-than-average share of vehicles have had serious defects recorded — the individual vehicle's history matters a lot here.

⚠️ Over 1 in 5 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
89.8%
UK average ~80%
Better than average
Dangerous (ever)
33.6%
At least once in MOT history
Check this vehicle
Avg failures / car
0.8
Over 6.8 tests on record
Moderate
Typical mileage
51k
Middle half: 39k–66k
For context
Good baseline reliability. A 89.8% 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 5.6 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 12,164 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.

Watch for defects — worth knowing

What tends to go wrong

Across 12,164 vehicles — figures show how many had each issue flagged at least once in their MOT history.

Tyre wear 35.5%
Nearside Rear Tyre worn close to legal limit/worn on edge · Offside Rear Tyre worn close to legal limit/worn on edge · Offside 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 27.3%
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.
Suspension & steering 11%
Offside Front Play in steering rack inner joint(s)
Harder to spot without a ramp — this is a good reason to book a pre-purchase inspection.
Other issues 10%
COVID-19 6 MONTH EXTENSION · Nearside Rear Child Seat fitted not allowing full inspection of adult belt · Windscreen damaged but not adversely affecting driver's view

Data covers a 3-year window centred on 2017.

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 12,164 BMW 420 cars.

UK

Before you buy a 2017 BMW 420

Based on MOT data from 12,164 vehicles — here's what to check.

  • 📋 Check the full MOT history. 33.6% 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
Diesel (78%) 9,462 89.6% 0.82
Petrol (22%) 2,702 90.5% 0.75

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 2017 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.

51,092
typical
39,010
low mileage
65,761
high mileage

Half of all 2017 BMW 420 vehicles fall between 39,010 and 65,761 miles.

Is the mileage you're seeing normal?
Under 39,010 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.
39,010–65,761 miles — normal for age. This is where most 2017 BMW 420s sit.
Over 88,777 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2017 BMW 420 — Still on the Road

Almost all 2017 BMW 420s are still on the road.

Strong survival — 10,669 vehicles still getting MOTs in 2025, 91% of the peak.

11,671 10,669 2020 2025

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2020–2025.
* The 2020 dip reflects the government's COVID-19 MOT exemption, which allowed certificates to be extended by six months — fewer tests were conducted that year.

MOT History Averages

6.8
Avg MOT tests per vehicle
0.8
Avg failures per vehicle
5.6
Avg advisories per vehicle
Other model years — BMW 420: All 420 years → Which year to buy? →
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Compare with another model

See how the 2017 BMW 420 stacks up against a rival.

Watch for defects — worth knowing