The picture
Cla: above-average pass rates, with caveats
Across 59,562 MOT tests, the Cla returns 82.7% first-time pass — above the UK fleet average. The single most-logged Major fail is tyre tread under the limit. A tyre with the cords showing and a seriously damaged tyre round out the top three. Average tested mileage sits at 55,576, 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
1,671 occurrences · 2.8% of tests
- 02
A tyre cords visible or damaged
1,557 occurrences · 2.6% of tests
- 03
A tyre seriously damaged
1,254 occurrences · 2.1% of tests
- 04
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
1,165 occurrences · 2.0% of tests
- 05
a brake lining or pad worn below 1.5mm
1,034 occurrences · 1.7% of tests
- 06
A spring or spring component fractured or seriously weakened
932 occurrences · 1.6% of tests
- 07
Wiper blade defective
672 occurrences · 1.1% of tests
- 08
A tyre seriously damaged
628 occurrences · 1.1% of tests
- 09
A suspension joint dust cover severely deteriorated
581 occurrences · 1.0% of tests
- 10
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
538 occurrences · 0.9% 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
£200–£350
If every one of this Cla'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
Brake pad measurement gauge
Testers fail pads under 1.5mm. A wear gauge tells you if you've got two months left or two weeks.
Search Amazon UK
Owner reports · Honest John
What owners actually report.
Verbatim faults logged by owners on honestjohn.co.uk over recent years. We didn't summarise — these are the words people typed in.
What's good
All the engines feature the ECO start/stop function as standard. The engines are combined with a six-speed manual transmission or with the 7G-DCT dual oil clutch (not dry clutch) automatic transmission, which reconciles comfort and sportiness in inimitable fashion.
Where it falls short
The all-new Mercedes-Benz CLA is available to order now, with prices starting from £24,355 OTR.
Buying or keeping a Cla?
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 Cla 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.