The picture
840i Auto: a strong MOT record by UK norms
Across 1,800 MOT tests, the 840i Auto returns 86.9% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is a tyre with the cords showing. A seriously damaged tyre and a seriously damaged tyre round out the top three. Average tested mileage sits at 23,737, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.
Top ten reasons for rejection.
- 01
A tyre cords visible or damaged
103 occurrences · 5.7% of tests
- 02
A tyre seriously damaged
90 occurrences · 5.0% of tests
- 03
A tyre seriously damaged
40 occurrences · 2.2% of tests
- 04
Tyre tread depth not in accordance with the requirements
22 occurrences · 1.2% of tests
- 05
Number plate does not conform to the specified requirements
16 occurrences · 0.9% of tests
- 06
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
16 occurrences · 0.9% of tests
- 07
A tyre seriously damaged
15 occurrences · 0.8% of tests
- 08
A tyre has a lump, bulge or tear caused by separation or partial failure of its structure. This includes any lifting of the tread rubber
10 occurrences · 0.6% of tests
- 09
Wiper blade defective
5 occurrences · 0.3% of tests
- 10
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
5 occurrences · 0.3% of tests
Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.
Worst-case fix budget · top 3 failures
£135–£225
If every one of this 840i Auto's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →
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Build your own retest budget.
Tools that pre-empt a retest.
Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.
Item 01 · Amazon UK
Digital tyre-tread depth gauge
Five quid for a gauge beats £150 for a retest. UK MOT minimum is 1.6mm — most testers fail anything below 2mm to be safe.
Search Amazon UK
Item 02 · Amazon UK
MOT-spec replacement number plate
Faded or non-standard plates fail outright. Replacements take ten minutes online with V5C details.
Search Amazon UK
Buying or keeping a 840i Auto?
Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.
If you own a 840i Auto and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.