Should I check the MOT history before buying a 2021 BMW 840i M Sport 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 M Sport 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 M Sport 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.

Is the 2021 BMW 840i M Sport Auto reliable?

Based on MOT data from 1,210 vehicles, the 2021 BMW 840i M Sport Auto has a first-time MOT pass rate of 91.6%, 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 M Sport 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 M Sport Auto (2021)

1,210 real MOT outcomes analysed • 91.6% first-time pass rate

2021 BMW 840i M Sport Auto

CarHunch analysed 1,210 real MOT records for the 2021 BMW 840i M Sport 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 Colour Breakdown Compare Models

This 2021 BMW 840i M Sport is noticeably more reliable than the UK average, with an 88.2% first-time MOT pass rate against the national 80%, and only 17.2% of vehicles have ever recorded a dangerous defect—a reasonable figure for a premium performance car. The petrol version achieves a solid 87.9% pass rate, confirming consistency across the fuel type.

At nearly 28,000 miles median, these cars are running light for their age, which partly explains the strong pass performance. The average of just 0.27 failures and 1.1 advisories per test signals that when problems do emerge, they're typically minor—so you're looking at a well-sorted machine that shouldn't drain your wallet on surprise repairs. Before purchase, request the full service history to confirm whether the previous owner kept up with BMW's maintenance intervals, as this model's complexity rewards preventive care.

The 2021 BMW 840i M Sport Auto passes its MOT first time at roughly the UK average rate (91.6%) — 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

91.6%

UK average ~80%

Better than average

Dangerous (ever)

17.2%

At least once in MOT history

Check this vehicle

Avg failures / car

0.27

Over 2.4 tests on record

Low

Typical mileage

28k

Middle half: 21k–37k

For context

✅ Good baseline reliability. A 91.6% first-time pass rate puts this well above the UK average — it's a well-sorted vehicle in this age bracket.

🔍 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 1,210 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 1,210 BMW 840i M Sport Auto cars.

Before you buy a 2021 BMW 840i M Sport Auto

Based on MOT data from 1,210 vehicles — here's what to check.

📋 Check the full MOT history. 17.2% 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 (97%)	1,171	91.4%	0.27

Colour Breakdown

Based on 3,790 BMW 840i M Sport Auto vehicles registered in the UK — across all years. From DVLA registration records.

Black 34.1%

1,293

Grey 30.8%

1,168

Blue 18.8%

714

Green 5.9%

222

White 5.6%

212

Orange 2.5%

Red 2.1%

Purple 0.2%

Mileage Distribution

Most 2021 BMW 840i M Sport 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.

27,974

typical

20,736

low mileage

37,101

high mileage

Half of all 2021 BMW 840i M Sport Auto vehicles fall between 20,736 and 37,101 miles.

Is the mileage you're seeing normal?

✓ Under 20,736 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.

✓ 20,736–37,101 miles — normal for age. This is where most 2021 BMW 840i M Sport Autos sit.

⚠ Over 50,086 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 M Sport Auto — Still on the Road

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

Strong survival — 1,100 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

0.27

Avg failures per vehicle

1.1

Avg advisories per vehicle

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

2020 2022 2023 2024 2025

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Average reliability — agree?