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Mercedes-Benz C-Class MOT pass rate and common problems

81.4% of 665,618 Mercedes-Benz C-Class MOT tests pass.

At 81.4%, the C-Class passes slightly less often than the average across all Mercedes-Benz models (83.5%).

The Mercedes-Benz C-Class has a pass rate of 81.4%, a little higher than the national average for cars (79.2%).

Own this Mercedes-Benz C-Class?

This is the average across every Mercedes-Benz C-Class in the dataset. Look up your own registration for its actual MOT history, and a free place to keep its maintenance records.

Have service invoices? Upload and keep them with your car’s history →

How to check and keep your Mercedes-Benz’s service history →

Pass rate by vehicle age

Pass rate drops sharply with age: the Mercedes-Benz C-Class tested at 0–3 years pass 91.2% of the time, compared with just 69.7% at 15+ years.

Pass rate by vehicle age band0–3 years91.2%3–6 years90.8%6–10 years86.4%10–15 years75.8%15+ years69.7%
Mercedes-Benz C-Class pass rate and average mileage by vehicle age band
Vehicle agePass rateTestsAverage mileage
0–3 years91.2%8,96726,879 miles
3–6 years90.8%105,70541,580 miles
6–10 years86.4%255,79771,947 miles
10–15 years75.8%176,985102,510 miles
15+ years69.7%118,164117,322 miles

Common MOT failure reasons for the Mercedes-Benz C-Class

The most common reason the Mercedes-Benz C-Class fails its MOT is suspension — present in 47.9% of failed tests, most often logged as "Ball joint excessively worn".

Top MOT failure categories for the Mercedes-Benz C-Class
CategoryShare of failed testsExample
Suspension47.9%Ball joint excessively worn
Tyres34.3%Tread depth below requirements of 1.6mm
Brakes34.0%Excessively corroded
Lamps, reflectors and electrical equipment29.5%Not working
Noise, emissions and leaks12.7%Inoperative or indicates a malfunction
Visibility9.3%Does not clear the windscreen effectively
Body, chassis, structure3.9%Has a major leak of exhaust gases
Road Wheels3.6%Fixing missing
Seat belts and supplementary restraint systems3.3%Warning lamp indicates a fault
Steering2.6%Ball joint has excessive play

Buying a used Mercedes-Benz C-Class: what to check

These checks follow the Mercedes-Benz C-Class’s own MOT record: the areas it fails on most often, and how that changes as the car gets older. None of them replaces a mechanic’s inspection, but they tell you where to look first.

The biggest drop in pass rate for the Mercedes-Benz C-Class comes between 6–10 years and 10–15 years old, from 86.4% to 75.8%. If you are looking at one in or just past that range, read its MOT history closely.

By mileage, the steepest fall is from 60,000–90,000 mi to 90,000–120,000 mi: 82.2% down to 75.9%. Mileage matters as well as age, so compare the car’s recorded mileages with its year.

  1. 1. Suspension

    Recorded in 47.9% of failed Mercedes-Benz C-Class MOTs. Rare on young cars, but 25.6% of tests at 15+ years failed on suspension.

    Listen for knocks over bumps and speed humps, and check the car sits level. Push down on each corner: it should settle rather than keep bouncing.

  2. 2. Tyres

    Recorded in 34.3% of failed Mercedes-Benz C-Class MOTs.

    Check tread depth across the whole width of every tyre, including the inner edge. Uneven wear can point to alignment or suspension problems. Look for cuts and bulges in the sidewalls.

  3. 3. Brakes

    Recorded in 34.0% of failed Mercedes-Benz C-Class MOTs. Rare on young cars, but 15.2% of tests at 15+ years failed on brakes.

    On the test drive, the car should stop straight without pulling or juddering, and the handbrake should hold it on a slope. Look through the wheels for scored or heavily lipped discs.

  4. 4. Lights and electrics

    Recorded in 29.5% of failed Mercedes-Benz C-Class MOTs. 18.3% of tests at 15+ years failed on lights and electrics, against 2.5% at 0–3 years.

    Walk round with the lights on: headlights (dipped and main), indicators, brake lights, fog light and number-plate lamp. Check the dashboard warning lights come on with the ignition, then go out once the engine starts.

  5. 5. Exhaust, emissions and leaks

    Recorded in 12.7% of failed Mercedes-Benz C-Class MOTs. Rare on young cars, but 6.4% of tests at 15+ years failed on exhaust, emissions and leaks.

    Look under the car for fresh oil or coolant, and listen for blows or rattles from the exhaust. Watch for smoke from the tailpipe when the engine starts and when you accelerate.

Check the car’s own MOT history. Averages describe the model, not the car in front of you. Look up its registration for past failures, advisories that were never fixed, and gaps or dips in the recorded mileage.

Ask for the service history. Invoices show what was done and when; a stamp alone shows less. See how to check Mercedes-Benz service history and what a service history check can tell you.

Related Mercedes-Benz models

Frequently asked questions

What is the MOT pass rate for the Mercedes-Benz C-Class?
81.4% of Mercedes-Benz C-Class MOT tests pass, based on 665,618 tests in the DVSA anonymised MOT tests and results dataset.
What are the most common MOT failures for the Mercedes-Benz C-Class?
The most common reason the Mercedes-Benz C-Class fails its MOT is suspension — present in 47.9% of failed tests, most often logged as "Ball joint excessively worn".
What are the common problems with the Mercedes-Benz C-Class?
Going by its MOT results, the most common problem areas on the Mercedes-Benz C-Class are suspension; tyres; brakes. Rare on young cars, but 25.6% of tests at 15+ years failed on suspension.
What should I check when buying a used Mercedes-Benz C-Class?
Start with the areas it most often fails its MOT on: suspension; tyres; brakes; lights and electrics; exhaust, emissions and leaks. Then check the specific car's MOT history by registration for failures, advisories and mileage, and ask the seller for service invoices.
Does this show the Mercedes-Benz C-Class's service history?
No — this is MOT test data, which covers roadworthiness, not servicing. A service history is a separate record of maintenance work, which a specific car only has if its owner has kept it. See the Mercedes-Benz service history guide for how to check and keep one.