Should I check the MOT history before buying a 2021 BMW 840i Auto?

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 840i Auto?

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 840i Auto?

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.

How many 2021 BMW 840i Auto vehicles have had dangerous defects recorded?

25% of these vehicles have had a dangerous defect recorded. Search the registration on CarHunch — the full MOT history will show exactly what was flagged and whether it was resolved.

Is the 2021 BMW 840i Auto reliable?

Based on MOT data from 133 vehicles, the 2021 BMW 840i Auto has a first-time MOT pass rate of 88.9%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

Do I need an HPI check when buying a 2021 BMW 840i Auto?

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 840i Auto (2021)

133 real MOT outcomes analysed • 88.9% first-time pass rate

2021 BMW 840i Auto

CarHunch analysed 133 real MOT records for the 2021 BMW 840i Auto. 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 Check a Specific Reg Buyer's Checklist Pass Rate by Fuel Mileage Distribution Still on the Road MOT Averages Compare Models

The 2021 BMW 840i is performing better than average on its MOT, with an 88.2% first-time pass rate well above the UK's 80%, though nearly a quarter of examples (24.8%) have experienced dangerous defects—a higher-than-typical concern that buyers should factor into their decision. The petrol engine variant maintains a solid 87.7% pass rate, so fuel type isn't a reliability dividing line here.

At just under 27,000 miles median—right on track for a three-year-old car—these 840is are showing modest failure rates of 0.38 per vehicle, suggesting most get through their early MOTs relatively unscathed. However, the average 1.1 advisories per test hints at minor wear accumulating, so have a pre-purchase inspection focus on brake condition and suspension components before committing.

We have limited data for the 2021 BMW 840i Auto — treat the figures below as indicative rather than definitive.

⚠️ 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

88.9%

UK average ~80%

Better than average

Dangerous (ever)

24.8%

At least once in MOT history

Check this vehicle

Avg failures / car

0.38

Over 2.6 tests on record

Low

Typical mileage

27k

Middle half: 19k–36k

For context

These stats describe 133 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?

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 133 BMW 840i Auto cars.

Before you buy a 2021 BMW 840i Auto

Based on MOT data from 133 vehicles — here's what to check.

📋 Check the full MOT history. 24.8% 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%)	128	88.4%	0.39

Mileage Distribution

Most 2021 BMW 840i Auto 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.

26,716

typical

18,782

low mileage

36,226

high mileage

Half of all 2021 BMW 840i Auto vehicles fall between 18,782 and 36,226 miles.

Is the mileage you're seeing normal?

✓ Under 18,782 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.

✓ 18,782–36,226 miles — normal for age. This is where most 2021 BMW 840i Autos sit.

⚠ Over 48,905 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 840i Auto — Still on the Road

Almost all 2021 BMW 840i Autos are still on the road.

Strong survival — 127 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

2.6

Avg MOT tests per vehicle

0.38

Avg failures per vehicle

1.1

Avg advisories per vehicle

Other model years — BMW 840i Auto: All 840i Auto years → Which year to buy? →

2019 2020

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Average reliability — agree?