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Mercedes-Benz C-Class W203/S203 (2000-2006) reliability

At a glance

Mercedes-Benz C-Class W203/S203 built around 2006: about average at the MOT

Mercedes-Benz C-Class W203/S203 models built around 2006 fail their MOT about as often as similar cars the same age. An independent inspection matters more than the wider numbers on cars this old.

Looking at a Mercedes-Benz C-Class W203/S203?

Enter its number plate to see its full MOT history, risk rating and running costs.

Key figure

30% of MOT tests on Mercedes-Benz C-Class W203/S203 models built around 2006 ended in a fail (retests included), against 28% for similar cars the same age.

Most common issue

The most common MOT issue on Mercedes-Benz C-Class W203/S203 models built around 2006 involves the suspension.

Mercedes-Benz C-Class W203/S203
No reliability rating: too close to call between ratings2000-2006SaloonDIESEL / PETROL

Based on 37,853 tests of C-Class models registered 2000-2006.

About 1 in 10 C-Class W203/S203 MOTs (9.8%) failed and still hadn't passed 3 days later. That's for cars built around 2006 (19 years old), all fuels combined.

Based on 11,086 tests (DVSA MOT results, 2025). A fail that passed a retest within 3 days, even the same day, isn't counted. Nor is a fail with no later MOT on record.

About 1 in 15 C-Class W203/S203 MOTs (7.4%) found at least one dangerous defect. These are cars built around 2006 (19 years old).

Based on 11,086 tests (DVSA MOT results, 2025). Dangerous is the most serious grade an MOT gives: a direct risk to road safety.

W203/S203 fail rate by age

Below typicalAbove typicalHigh (28% or more)Highest fail rateUK average for cars this age
Age / builtFail rateMOT tests
18 yearsbuilt around 2007
5,59731.0%
19 yearsbuilt around 2006
11,08629.9%
20 yearsbuilt around 2005
8,17330.5%
21 yearsbuilt around 2004
6,10931.4%
22 yearsbuilt around 2003
3,59629.4%
23 yearsbuilt around 2002
2,01228.3%
24 yearsbuilt around 2001
91727.2%
25+ yearsbuilt 2000 or earlier
36326.2%

Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs. Highest fail rate at 21 years old.

How the C-Class W203/S203 compares

At each age below, see how the C-Class W203/S203 holds up against other cars the same age. The averages combine all fuel types.

Based on 35,889 tests across 13 Mercedes-Benz models, built around 2006 (19 years old).

Below typicalAbove typicalHigh (28% or more)Highest fail rateMercedes-Benz average
Age / builtFail rateMOT tests
18 yearsbuilt around 2007
5,59731.0%
19 yearsbuilt around 2006
11,08629.9%
20 yearsbuilt around 2005
8,17330.5%
21 yearsbuilt around 2004
6,10931.4%
22 yearsbuilt around 2003
3,59629.4%
23 yearsbuilt around 2002
2,01228.3%
24 yearsbuilt around 2001
91727.2%
25+ yearsbuilt 2000 or earlier
36326.2%

Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs.

What to check before viewing

The model's most common MOT issues, turned into things you can ask about or look for.

Brake pipes and hoses

High priority

Look under the car for corrosion or chafing on the rigid brake pipes near the rear axle.

Suspension bushes and joints

Worth checking

Listen for knocks over speed bumps and ask about recent control-arm or anti-roll-bar work.

Tyres

Worth checking

Check tread depth across the full width on all four; uneven wear suggests alignment or suspension issues.

Suspension springs

Worth checking

Check ride height is even side-to-side and look for cracked or rusted coils.

Suspension

Worth checking

Inspect the suspension carefully and ask the seller for repair history.

Vehicle-specific check

Worth checking

Check the car’s number plate on MOT Wise to see its own MOT history and any recalls for its build years.

Other saloons to compare

Other saloons, with each one's figures taken at the same age as the C-Class W203/S203.

  1. 1

    Lexus IS

    Same body type, tested at the same age

    Fail rate
    25.1%

    Lower fail rate: 25.1%, against 29.9% for the Mercedes-Benz C-Class W203/S203, both built around 2006.

    Some figures could not be compared for these two cars. So this comparison uses the fail rate and recalls only.

    1,904 MOT tests on cars built around 2006

  2. 2

    Jaguar XJ

    Same body type, tested at the same age

    Fail rate
    23.2%
    Fail, no pass in 3 days
    9.3%
    Dangerous
    6.6%
    Still registered at 10 years
    93.8%

    Lower fail rate: 23.2%, against 29.9% for the Mercedes-Benz C-Class W203/S203, both built around 2006.

    5 critical recall campaigns matching this model/build period.

    1,362 MOT tests on cars built around 2006

  3. 3

    Saab 9-3

    Same body type, tested at the same age

    Fail rate
    28.9%
    Fail, no pass in 3 days
    9.1%
    Dangerous
    6.9%

    No clear edge over the Mercedes-Benz C-Class W203/S203 on these figures.

    4,958 MOT tests on cars built around 2006

  4. 4

    Audi A6

    Same body type, tested at the same age

    Fail rate
    27%
    Fail, no pass in 3 days
    7.4%
    Dangerous
    8.3%
    Still registered at 10 years
    79.1%

    Lower fail rate: 27.0%, against 29.9% for the Mercedes-Benz C-Class W203/S203, both built around 2006.

    4 critical recall campaigns matching this model/build period.

    2,592 MOT tests on cars built around 2006

Fail rate
= the share of MOT tests that ended in a fail. Retests count as tests.
Fail, no pass in 3 days
= the share of MOT tests that failed and still hadn't passed 3 days later. A fail that passed a retest within 3 days, even the same day, isn't counted.
Dangerous
= the share of MOT tests where the tester marked a fault as dangerous. It is against the law to drive the car until it is fixed.
Still registered at 10 years
= the share of cars still registered (taxed or declared off the road) 10 years after they were first registered.

How many are still registered

87%of all Mercedes-Benz C-Class cars first registered in 2014 to 2015 were still registered 10 years later. This is the whole model, not only this generation.

UK average for cars first registered in 2014 to 2015: 92% · Fewer than typical

The share still registered can reflect demand, the cost of repairs, exports, write-offs and how owners use the car. It isn't proof of how long the car lasts mechanically.

Source: DfT vehicle licensing statistics (VEH0124).

Recall context

158 recalls in all

10 of the 158 C-Class W203/S203 recalls cover cars built in these years.

  • 2 Critical
  • 8 more

Top concerns

  • The passenger air bag may not deploy as specified
  • Takata airbag might not deploy as specified
  • On affected vehicles the bonding between the glass panel and the sliding roof frame might not meet specifications. In c

For the exact car, check GOV.UK's recall checker with the number plate.

What has gone wrong on C-Class W203/S203 cars built around 2006

The share of petrol cars that have ever failed an MOT on each part of the car. Based on 1,188 cars.

Structural systems

Suspension
84%
Emissions
39%
Steering
5%

Wear items

Tyres
59%
Lighting
59%
Brakes
57%

Rust, which the MOT calls corrosion: 18% of these cars show rust-related issues at this age.

Check the sills, subframe and brake pipes before you decide.

How C-Class W203/S203 cars have aged

How C-Class W203/S203 cars have aged

How fail rates have changed as these cars got older. Each line follows cars first registered in about the same year across several years of MOT data. Not a prediction for any one car.

0%10%20%30%151719212325Age at MOTBuilt around 2006, 15 years old at the time of MOT: 30.0% (11,435 tests, 2021 data)Built around 2006, 16 years old at the time of MOT: 29.0% (9,998 tests, 2022 data)Built around 2006, 17 years old at the time of MOT: 29.7% (8,638 tests, 2023 data)Built around 2006, 18 years old at the time of MOT: 30.3% (7,374 tests, 2024 data)Built around 2006, 19 years old at the time of MOT: 30.0% (6,168 tests, 2025 data)2006Built around 2005, 16 years old at the time of MOT: 32.2% (10,614 tests, 2021 data)Built around 2005, 17 years old at the time of MOT: 30.8% (8,948 tests, 2022 data)Built around 2005, 18 years old at the time of MOT: 31.1% (7,395 tests, 2023 data)Built around 2005, 19 years old at the time of MOT: 31.1% (5,992 tests, 2024 data)Built around 2005, 20 years old at the time of MOT: 30.1% (4,753 tests, 2025 data)2005Built around 2004, 17 years old at the time of MOT: 32.1% (9,069 tests, 2021 data)Built around 2004, 18 years old at the time of MOT: 31.5% (7,372 tests, 2022 data)Built around 2004, 19 years old at the time of MOT: 31.1% (5,860 tests, 2023 data)Built around 2004, 20 years old at the time of MOT: 30.5% (4,747 tests, 2024 data)Built around 2004, 21 years old at the time of MOT: 31.1% (3,732 tests, 2025 data)2004Built around 2003, 18 years old at the time of MOT: 31.5% (6,500 tests, 2021 data)Built around 2003, 19 years old at the time of MOT: 30.1% (4,958 tests, 2022 data)Built around 2003, 20 years old at the time of MOT: 30.4% (3,924 tests, 2023 data)Built around 2003, 21 years old at the time of MOT: 30.5% (3,083 tests, 2024 data)Built around 2003, 22 years old at the time of MOT: 30.3% (2,372 tests, 2025 data)2003Built around 2002, 19 years old at the time of MOT: 30.2% (3,931 tests, 2021 data)Built around 2002, 20 years old at the time of MOT: 28.2% (2,924 tests, 2022 data)Built around 2002, 21 years old at the time of MOT: 29.4% (2,285 tests, 2023 data)Built around 2002, 22 years old at the time of MOT: 29.5% (1,735 tests, 2024 data)Built around 2002, 23 years old at the time of MOT: 28.3% (1,344 tests, 2025 data)2002Built around 2001, 20 years old at the time of MOT: 29.6% (1,872 tests, 2021 data)Built around 2001, 21 years old at the time of MOT: 28.9% (1,393 tests, 2022 data)Built around 2001, 22 years old at the time of MOT: 27.4% (1,096 tests, 2023 data)Built around 2001, 23 years old at the time of MOT: 28.0% (811 tests, 2024 data)Built around 2001, 24 years old at the time of MOT: 28.0% (644 tests, 2025 data)2001Built around 2000, 21 years old at the time of MOT: 28.1% (1,095 tests, 2021 data)Built around 2000, 22 years old at the time of MOT: 28.2% (839 tests, 2022 data)Built around 2000, 23 years old at the time of MOT: 27.0% (618 tests, 2023 data)Built around 2000, 24 years old at the time of MOT: 25.0% (420 tests, 2024 data)Built around 2000, 25 years old at the time of MOT: 26.2% (363 tests, 2025 data)2000
First registered around 2006First registered around 2005First registered around 2004First registered around 2003
How each part holds up as W203/S203 cars age

How each part holds up as W203/S203 cars age

The share of petrol cars built pre-2005 that have ever failed an MOT on each part of the car. Rates usually rise with age, but can dip slightly as cars leave the road.

Part of the car21 years22 years23 years24 years
Suspension84%83%76%74%
Brakes57%47%47%47%
Emissions39%42%38%31%
Tyres59%57%57%51%
Lighting59%55%57%56%
BodyworkNo figure1%1%1%
Steering5%4%4%8%
Corrosion18%12%12%11%

Based on petrol cars in the pre-2005 build-year band, from 1,108 to 1,502 cars at each age.

W203/S203 variants compared

C-Class W203/S203 variants built around 2006

The fail rate for each C-Class W203/S203 variant, grouped by fuel. Each row counts fails per MOT test, the same way as the main fail rate chart.

Petrol

  • C29.4%6,593 tests

Diesel

  • C30.7%4,463 tests
All generations of this modelPlenty of data

Most common issues on Mercedes-Benz C-Class models of this age

This list covers every Mercedes-Benz C-Class built around 2006, whichever generation it is. We don't have a defect list for the W203/S203 on its own.

Most common advisories and fails

In order of the share of MOT tests that recorded each one

  1. 1
    Advisory

    Suspension arm pin or bush worn, but not moving too much

    30.8%
    Advisory: 4,276Fail: 1,543 (27% of the times it was found)
  2. 2
    Advisory

    Tyre worn close to the legal limit or worn on the edge

    24.0%
    Advisory: 3,625Fail: 389 (10% of the times it was found)
  3. 3
    Advisory

    Brake pipe corroded or covered in grease

    20.9%
    Advisory: 3,619Fail: 239 (6% of the times it was found)
  4. 4
    Advisory

    Coil spring corroded

    20.1%
    Advisory: 2,716Fail: 533 (16% of the times it was found)
  5. 5
    Advisory

    Suspension part corroded, but not seriously weakened

    18.3%
    Advisory: 2,875Fail: 32 (1% of the times it was found)

Based on 11,086 tests

Looking at a Mercedes-Benz C-Class W203/S203?

Enter its number plate to see its full MOT history, risk rating and running costs.

Frequently asked questions

Built around 2006 (19 years old), the Mercedes-Benz C-Class W203/S203 (2000-2006) fails MOTs at about the rate typical for this age. This is based on 11,086 19-year-old MOT tests from DVSA data. Each retest counts as a test.

*The build year is worked out from the date a car was first used on UK roads. For most cars this matches when it was registered, but imports may differ by a few months.

Data sourced from DVSA MOT History API. From 37,853 MOT tests on Mercedes-Benz C-Class models first registered between 2000-2006. These figures are a guide, not a guarantee.