The picture
Tdm850: a strong MOT record by UK norms
Across 618 MOT tests, the Tdm850 returns 85.3% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is tyre tread under the limit. Lamp missing or inoperative and a non-functioning shock absorber round out the top three. Average tested mileage sits at 35,265, 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
Tyre tread depth not in accordance with the requirements
10 occurrences · 1.6% of tests
- 02
A lamp missing or inoperative
9 occurrences · 1.5% of tests
- 03
A shock absorber not functioning or leaking severely
9 occurrences · 1.5% of tests
- 04
Stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning
7 occurrences · 1.1% of tests
- 05
Significant brake effort recorded with no brake applied indicating a binding brake
5 occurrences · 0.8% of tests
- 06
A wheel bearing with excessive play
5 occurrences · 0.8% of tests
- 07
Brake disc or drum significantly and obviously worn
4 occurrences · 0.6% of tests
- 08
A tyre with a lump, bulge or tear caused by separation or partial failure of its structure, including any lifting of the tread rubber
4 occurrences · 0.6% of tests
- 09
Audible warning not working
4 occurrences · 0.6% of tests
- 10
Projected beam image is obviously incorrect
4 occurrences · 0.6% 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 2 failures
£68–£130
If every one of this Tdm850'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
H7 / W21W bulb pack
A spare-bulb kit lives in the boot. Test morning is not the time to find your stop-lamp's gone.
Search Amazon UK
Buying or keeping a Tdm850?
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 Tdm850 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.