Common problems

Mercedes-Benz CLA common problems

What MOT testers find on the Mercedes-Benz CLA: the parts that fail or get advisories most often at each age, against all cars of the same age. From 243,385 DVSA MOT tests taken 2022 to 2025.

MOT data updated 28 September 2026

At 3 years, the most tested age

Tyres fails per 100 MOTs (n=39,186)7.6

All cars at 3 years (n=8,016,463)4.8

Tyres advisories and minor defects per 100 MOTs (n=39,186)23.6

All cars, same age (n=8,016,463)18.1

What stands out

Tyres fails show up on 7.6 of every 100 MOTs of a Mercedes-Benz CLA at 3 years old (n=39,186), against 4.8 for all cars of that age (n=8,016,463).
The fail item testers record most often at 3 years: tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords, on 3.0 per 100 MOTs (all cars 1.8).
The most common advisory or minor defect: tread depth: worn close to legal limit/worn on edge, on 14.2 per 100 MOTs.

Problems by part at 3 years

How many of every 100 MOTs found a fail, or an advisory or minor defect, in each area. A test with faults in two areas counts in both.

Mercedes-Benz CLA at 3 years (n=39,186) against all cars at 3 years (n=8,016,463). Per 100 MOTs.
Area	Fails	All cars	Advisories	All cars
Tyres	7.6	4.8	23.6	18.1
Lights and electrics	2.2	2.9	0.6	0.7
Windscreen, wipers and mirrors	2.0	2.8	3.6	2.8
Brakes	1.8	1.7	8.8	8.8
Seat belts and airbags	0.7	0.3	0.1	0.1
Number plates and VIN	0.5	0.2	0.6	0.5
Suspension	0.5	0.6	1.5	1.9
Road wheels	0.4	0.1	0.6	0.4
Exhaust, emissions and leaks	0.3	0.5	0.2	0.4
Body and structure	0.2	0.3	0.1	0.3
Steering	0.1	0.1	0.1	0.1

What testers fail most on the CLA at 3 years

Fail items on the Mercedes-Benz CLA at 3 years (n=39,186), per 100 MOTs, with all cars at the same age (n=8,016,463).
Item	Area	Per 100 MOTs	All cars	Typical repair (estimate)
Tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords	Tyres	3.0	1.8	£88 to £145 per tyre
Tyre with cords exposed	Tyres	2.2	1.0	£88 to £145 per tyre
Tyre tread below 1.6 mm	Tyres	1.7	1.3	£88 to £145 per tyre
Wipers not clearing screen	Windscreen, wipers and mirrors	1.1	1.9	£15 to £30 per blade
Brake pads under 1.5 mm	Brakes	1.0	1.0	£72 to £174 per axle (rough guide)
Headlight aimed too high	Lights and electrics	0.9	0.9	£16 to £39 per car (rough guide)
Headlamp aim: too low	Lights and electrics	0.8	0.6	£16 to £39 per car (rough guide)
Washers: provides insufficient washer liquid	Windscreen, wipers and mirrors	0.6	0.6	£2 to £14 per car (rough guide)
Brake pads: worn down to wear indicator	Brakes	0.5	0.1	£72 to £174 per axle (rough guide)
Airbag (SRS) warning light on	Seat belts and airbags	0.5	0.1	diagnosis from £39 (rough guide)

Early warnings: advisories and minor defects at 3 years

Advisories and minor defects are recorded, but the car still passes. Across all cars, a part with an advisory or minor defect failed at the next MOT 5.5 times in 100 (n=88,666,940 pairs of consecutive MOTs), against 0.3 times in 100 when the same part had none (n=12,936,860,350).

Advisories and minor defects on the Mercedes-Benz CLA at 3 years (n=39,186), per 100 MOTs, with all cars at the same age (n=8,016,463).
Item	Area	Per 100 MOTs	All cars	If it needs replacing (estimate)
Tread depth: worn close to legal limit/worn on edge	Tyres	14.2	11.8	£88 to £145 per tyre
Tyre condition: slightly damaged/cracking or perishing	Tyres	6.8	3.7	£88 to £145 per tyre
Brake pads: wearing thin	Brakes	6.1	4.8	£72 to £174 per axle (rough guide)
Tyre condition: has a cut but not deep enough to reach the ply or cords	Tyres	2.6	2.0	£88 to £145 per tyre
Tread depth: worn close to legal limit/worn on edge	Tyres	2.5	1.8	£88 to £145 per tyre
Nail in tyre	Other	2.4	2.3
Brake discs: worn, pitted or scored, but not seriously weakened	Brakes	2.1	3.9	£148 to £376 per axle (rough guide)
Child Seat fitted not allowing full inspection of adult belt	Other	1.9	2.1
Brake discs: worn, but not excessively	Brakes	1.9	1.1	£148 to £376 per axle (rough guide)
Windscreen: damaged but not adversely affecting driver's view	Windscreen, wipers and mirrors	1.9	1.5

Repair estimates are a guide for an independent garage: labour at the national median local garage rate (median £78 an hour from 65 garages, ONS price quotes) times estimated labour hours, plus a parts band. Labour hours and most parts bands are estimates, not quotes, and prices vary by model, engine and region. A warning light fault shows the cost of the diagnosis only.

How problems change with age

Fails per 100 MOTs in the three most common areas at 3 years. Ages with fewer than 1,000 tests are not shown.
Age	Tests (n)	Tyres	Lights and electrics	Windscreen, wipers and mirrors
3 years	39,186	7.6	2.2	2.0
4 years	35,418	7.6	2.2	2.2
5 years	33,319	8.5	2.4	2.6
6 years	33,041	9.2	2.4	3.0
7 years	31,680	9.4	2.8	3.3
8 years	27,549	9.2	3.6	3.3
9 years	21,324	9.4	4.6	3.2
10 years	13,326	9.9	5.6	3.6
11 years	6,447	9.4	6.5	4.2
12 years	2,095	8.4	7.2	5.0

Mileage

At 3 years, Mercedes-Benz CLA cars showing under 30,000 miles failed 11.5% of MOTs (n=24,062); the band that failed most, 60,000 to 90,000 miles, failed 20.0% (n=1,373). For pass and fail rates by age, see Mercedes-Benz CLA MOT fail rates.

What to check on a viewing

On the Mercedes-Benz CLA, testers most often record tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords; tyre with cords exposed; tyre tread below 1.6 mm. Look at these first, then the areas below.

Tyres

Check the tread across the full width of all four tyres, and the spare if there is one.
Look for cuts, bulges and cracking in the sidewalls.
Wear on one edge only can point to worn suspension or the tracking being out.

Lights and electrics

With someone outside, try every light: dipped and main beam, indicators, brake lights, fog lights and number plate lamps.
Check that the warning lights come on with the ignition and go out once the engine runs.
Look for misted, cracked or yellowed headlamp lenses.

Windscreen, wipers and mirrors

Look for chips or cracks in the windscreen, above all in front of the driver.
Run the wipers and washers: they should clear the screen without smearing.
Check that the mirrors are present, secure and not cracked.

Ask for the car's MOT history and service record: advisories that repeat from one year to the next show what has been left. GOV.UK MOT history.

Questions

What are the most common problems on the Mercedes-Benz CLA?

At 3 years, the age with the most MOT tests (39,186), the fail items testers record most often on the Mercedes-Benz CLA are tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords (3.0 per 100 MOTs), tyre with cords exposed (2.2 per 100 MOTs), tyre tread below 1.6 mm (1.7 per 100 MOTs). The most common advisories or minor defects are tread depth: worn close to legal limit/worn on edge (14.2) and tyre condition: slightly damaged/cracking or perishing (6.8).

Which parts of the Mercedes-Benz CLA fail more often than on other cars?

At 3 years: tyres (7.6 per 100 MOTs against 4.8 for all cars). Compared with 8,016,463 MOTs of all cars the same age.

Mercedes-Benz CLA problems by area

Other Mercedes-Benz models

All Mercedes-Benz models · Common problems by make

Read this with care. A fail rate is not a measure of build quality. How far cars are driven, how they are used and how well owners maintain them all change it, and wear items such as tyres and brake pads are common fails. Compare a model only with cars of the same age. Methodology and limits.

The all cars figures cover all class 4 vehicles (cars and light vans) tested at the same age.

Looking at a Mercedes-Benz CLA?

These figures describe the model, not the car in front of you. Found one you might buy? See what the VetTheCar Buying Report covers, or use the tools that work without a registration.

See a sample report Car tools · MOT fail rates by model · Compare models by MOT record

Repair estimates: ONS consumer price quotes for local garage labour (09/2025 to 08/2026), the MOT inspection manual for defect wording, and estimated labour hours and parts bands. Not affiliated with or endorsed by ONS.

Source

Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025. MOT data updated 28 September 2026.

Not affiliated with or endorsed by DVSA. How we calculate these figures · Data sources