The picture
Ml 250: middle-of-the-pack on first-time pass
Across 534 MOT tests, the Ml 250 returns 76.2% first-time pass — roughly in line with the UK fleet average. The single most-logged Major fail is a split CV-joint boot. A broken or weak spring and tyre tread under the limit round out the top three. Average tested mileage sits at 105,778, 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 transmission shaft constant velocity joint boot severely deteriorated
42 occurrences · 7.9% of tests
- 02
A spring or spring component fractured or seriously weakened
40 occurrences · 7.5% of tests
- 03
Tyre tread depth not in accordance with the requirements
20 occurrences · 3.7% of tests
- 04
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
18 occurrences · 3.4% of tests
- 05
A tyre seriously damaged
12 occurrences · 2.2% of tests
- 06
a brake lining or pad worn below 1.5mm
9 occurrences · 1.7% of tests
- 07
Engine MIL illuminated indicating a malfunction
9 occurrences · 1.7% of tests
- 08
A lamp with a multiple light source up to 1/2 not functioning
9 occurrences · 1.7% of tests
- 09
A tyre cords visible or damaged
8 occurrences · 1.5% of tests
- 10
A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc
8 occurrences · 1.5% 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
£140–£335
If every one of this ML 250'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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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.
Buying or keeping a ML 250?
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 ML 250 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.