Mercedes-Benz GLC MOT failure rate and common faults

83,694 Mercedes-Benz GLC cars aged 3 to 20 took their MOT in 2025, and 13.7% failed at the first attempt. An average car of the same age failed 17.9% of the time, which makes the Mercedes-Benz GLC 24% less likely to fail than the typical car on the road. Here is what fails, and which years to look for.

13.7%

failed first time

83,694 MOT tests in 2025

-24%

vs same age average

average car of this age mix: 17.9%

39 of 208

age adjusted rank

among cars; 1 fails least

56.9

dangerous defects per 1,000

same age average: 76.7

What fails on a Mercedes-Benz GLC MOT

Failure items recorded per 1,000 tests, by part of the car, set against an average car with exactly the same spread of ages. A figure well above average is a weak spot worth checking before you buy.

Tyres72 about average
Suspension47 about average
Brakes23 54% below average
Windscreen, wipers and mirrors16 57% below average
Lights and electrics15 78% below average
Engine, emissions and leaks14 14% below average
Body, chassis, exhaust and drive shafts14 1.3x average
Number plates and VIN6 2.0x average
Seat belts and airbags2 45% below average
Wheels2 33% below average

The most common Mercedes-Benz GLC MOT failures

The individual failure items testers recorded most often, per 1,000 tests.

Failure itemAreaPer 1,000 tests
Ball joint excessively wornSuspension34.3
Tyres: has a cut in excess of the requirements deep enough to reach the ply or cordsTyres23.8
Tread depth below requirements of 1.6mmTyres22.3
Tyres: has ply or cords exposedTyres14.4
Malfunction indicator lamp: inoperative or indicates a malfunctionEngine, emissions and leaks13.7
Drive shafts: constant velocity boot split or insecure, no longer prevents the ingress of dirtBody, chassis, exhaust and drive shafts11.3
Brake pads: less than 1.5 mm thickBrakes10.0
Coil spring: fractured or brokenSuspension7.5
Wipers: does not clear the windscreen effectivelyWindscreen, wipers and mirrors6.2
Washers: provides insufficient washer liquidWindscreen, wipers and mirrors5.7
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Mercedes-Benz GLC MOT failure rate by year

Every car fails more often as it ages, so each registration year is compared with the average for all cars of the same age. Years with fewer than 500 tests are left out.

First registeredTestsFailedSame age averageAverage mileage
20227,1568.9%11.4%29,800
20216,5369.3%12.8%39,000
202011,08210.3%14.1%44,000
201917,15513.4%16.5%50,600
201818,91315.9%19.1%59,400
201712,45216.0%21.8%69,900
20169,08117.2%25.1%79,400
20151,31417.1%28.1%83,400

Advisories to look for in a Mercedes-Benz GLC's MOT history

An advisory is a tester's warning that something is wearing but has not failed yet. These are the ones written most often on the Mercedes-Benz GLC, per 1,000 tests. If the car you are looking at has one of these, ask whether it has been fixed since.

  • Tread depth: worn close to legal limit/worn on edge290.2
  • Brake pads: wearing thin97.8
  • Ball joint has slight play76.1
  • Tyres: slightly damaged/cracking or perishing73.8
  • Brake discs: worn, pitted or scored, but not seriously weakened70.5
  • Brake discs: worn, but not excessively55.5

Checking a used Mercedes-Benz GLC before you buy

Against cars of the same age, the Mercedes-Benz GLC fails more often than average on body, chassis, exhaust and drive shafts. Start there.

  • Body, chassis, exhaust and drive shafts

    Turn the steering to full lock and look behind each front wheel: the rubber boots on the drive shafts should be whole, with no grease sprayed around. Then get down with a torch and check the exhaust hangers, sills, floor and subframes for rust.

Averages only take you so far. The specific car's MOT history shows whether it has already failed on any of these, how often advisories were ignored, and whether the mileage climbs steadily from test to test. Read our guide to reading a car's MOT history before you go to view it.

Fuel mix of the Mercedes-Benz GLC cars tested: Diesel 76%, Petrol 15%, Hybrid 7%. Average age at test 6.4 years, average recorded mileage 55,500.

Mercedes-Benz GLC MOT questions

What is the Mercedes-Benz GLC MOT failure rate?

13.7% of Mercedes-Benz GLC cars failed their first MOT test of 2025, from 83,694 tests on vehicles aged 3 to 20. An average car with the same age mix failed 17.9% of the time, so the Mercedes-Benz GLC was 24% less likely to fail.

What fails most often on a Mercedes-Benz GLC MOT?

Tyres caused the most failure items, at 72 per 1,000 tests. The single most common failure item was "Ball joint excessively worn", recorded 34.3 times per 1,000 tests.

Which Mercedes-Benz GLC year has the best MOT record?

Measured against cars of the same age, 2015 registrations did best: 17.1% failed against an average of 28.1% for cars that age. Older cars always fail more often, so compare a year with its age group rather than with newer cars.

Does this tell me whether a particular Mercedes-Benz GLC will pass?

No. These are averages across every Mercedes-Benz GLC tested in 2025. The car in front of you has its own record: its full MOT history shows every pass, failure and advisory it has had, and it is free to view by registration.

Other Mercedes-Benz models

Ranked close to the Mercedes-Benz GLC

How these figures are calculated

Source: DVSA Anonymised MOT tests and results, 2025 release. We count first tests of cars and small vans (class 4) aged 3 to 20, so a car that fails and is retested is counted once. A failure includes faults fixed and passed within the same visit. The same age average weights the national failure rate for each age by how many Mercedes-Benz GLC cars of that age were tested, so a model is never penalised for having an older fleet. Make and model are as recorded at the test; trim levels are combined. Full method and rankings.

Contains public sector information licensed under the Open Government Licence v3.0.