MOT fail rates by first-use year

2004 Mercedes-Benz A-Class MOT fail rate and common faults

How Mercedes-Benz A-Class cars first used in 2004 did at their MOTs from 2022 to 2024, against all cars of the same age. From 4,975 DVSA MOT tests of these cars. First use is usually the date the car was first registered.

MOT data updated 28 September 2026

At 20 years, tested in 2024

MOT fail rate at age 20 (n=1,267)43.6%

All cars at 20 years (n=1,845,952)42.8%

Difference+0.9 pts

MOT tests of 2004 cars, 2022 to 20244,975

What stands out

In 2024, at 20 years old, Mercedes-Benz A-Class cars first used in 2004 failed 43.6% of MOTs (1,267 tests), about the same as the 42.8% for all cars that age.
From 2022 to 2024, as these cars went from 18 to 20 years old, the fail rate moved from 46.2% to 43.6%.
Mercedes-Benz A-Class cars first used a year earlier, in 2003, failed 46.4% at the same age of 20 years (1,706 tests, in 2023).
The most common fail item that is not a wear item, for the Mercedes-Benz A-Class at 20 years, is coil spring broken, at 6.2 per 100 MOTs (all cars: 2.6).

MOT fail rate by test year

Mercedes-Benz A-Class cars first used in 2004: share of MOT tests that failed, by test year, against all cars of the same age. Years with fewer than 1,000 tests are not shown.
Test year	Age	MOT fail rate	Tests (n)	All cars	Difference
2022	18 years	46.2%	2,073	43.3%	+2.9 pts
2023	19 years	45.6%	1,635	43.2%	+2.4 pts
2024	20 years	43.6%	1,267	42.8%	+0.9 pts

Most common faults at 20 years

These figures cover all Mercedes-Benz A-Class MOTs at 20 years: cars first used 2002 to 2005, tested 2022 to 2025 (n=7,083). The list uses every first-use year so it has enough tests. Wear items (tyres, brake pads, wipers, bulbs) say more about upkeep than about the design.

MOT fail items

Fail item	Per 100 MOTs	All cars
Brake light not working Wear	6.6	3.9
Coil spring broken	6.2	2.6
Headlamp aim: projected beam image is obviously incorrect Wear	4.8	4.0
Rigid brake pipes: excessively corroded	4.1	2.5
Washers: provides insufficient washer liquid Wear	4.0	2.2
Driveshaft CV boot split	3.9	3.1
Engine warning lamp at the petrol emissions check: not working or showing a fault	3.5	2.5
Side/position light not working Wear	3.4	5.2
Wipers not clearing screen Wear	3.3	3.4
Dipped headlight not working Wear	3.2	1.9

Per 100 of the MOTs above (n=7,083). A test with two items counts once for each.

Advisories

Advisory	Per 100 MOTs	All cars
Rigid brake pipes: corroded, covered in grease or other material	27.4	15.2
Tyre tread close to the legal limit or worn on the edge Wear	14.2	15.7
Tyre condition: slightly damaged/cracking or perishing Wear	14.0	10.2
Brake discs: worn, pitted or scored, but not seriously weakened	10.2	10.7
Registration plates: deteriorated but not likely to be misread Wear	9.2	6.2
Shock absorber misting oil	9.1	3.3
Flexible brake hoses: slightly deteriorated	8.4	2.2
Coil spring: corroded	8.2	8.0
Registration plate lamp(s): inoperative in the case of multiple lamps or light sources Wear	7.2	5.4
Suspension pin or bush worn, without excessive movement	6.7	7.7

Per 100 of the MOTs above (n=7,083). A test with two items counts once for each.

Fuel type at 20 years

These figures cover all Mercedes-Benz A-Class MOTs at 20 years: cars first used 2002 to 2005, tested 2022 to 2025 (n=7,083). Each fuel is set against all cars of the same fuel and age. Fuels with fewer than 1,000 tests are not shown.

Fuel	Share of tests	MOT fail rate	Tests (n)	All cars, same fuel	Median mileage
Petrol	83.9%	43.2%	5,942	42.5%	78,337 miles
Diesel	16.1%	47.1%	1,141	43.6%	92,664 miles

Fail rate by mileage at 20 years

These figures cover all Mercedes-Benz A-Class MOTs at 20 years: cars first used 2002 to 2005, tested 2022 to 2025 (n=7,083). At 20 years, Mercedes-Benz A-Class cars at 90,000 to 120,000 miles failed more often (47.1%, n=1,714) than those at 30,000 to 60,000 miles (35.7%, n=1,311). Bands with fewer than 1,000 tests are not shown.

Mileage at test	MOT fail rate	Tests (n)	All cars
30,000 to 60,000 miles	35.7%	1,311	33.4%
60,000 to 90,000 miles	43.0%	2,437	41.3%
90,000 to 120,000 miles	47.1%	1,714	45.5%

Car tax rules for a 2004 car

Cars first registered from 1 March 2001 to 31 March 2017 are taxed by CO2 emissions band, from band A (the lowest emissions) to band M. The band is set by the CO2 figure on the V5C logbook.

These are the rules, not the amount for a specific car. Car tax check

ULEZ and clean air zones

Many petrol cars first registered from 2001 to 2005 already meet Euro 4, but not all of them. For a 2004 petrol car the Euro standard of that car decides.
Diesel cars first registered before September 2015 usually do not meet Euro 6, so a 2004 diesel usually pays the ULEZ daily charge. A few models met Euro 6 early.
The clean air zones in Birmingham and Bristol use the same Euro 4 petrol and Euro 6 diesel standards. The low emission zones in Scotland use them too, but enforce them with fines, not a daily charge.

The Euro standard of the car decides, not the year alone. ULEZ checker

Other years of the Mercedes-Benz A-Class

2003 Mercedes-Benz A-Class 2005 Mercedes-Benz A-Class

Other Mercedes-Benz models first used in 2004

Model	Age at test	MOT fail rate	Tests (n)	All cars
Mercedes-Benz C-Class (2004)	21 years in 2025	41.3%	5,407	42.1%
Mercedes-Benz E-Class (2004)	21 years in 2025	31.2%	3,406	42.1%
Mercedes-Benz CLK (2004)	21 years in 2025	36.6%	3,466	42.1%
Mercedes-Benz SLK (2004)	21 years in 2025	33.4%	2,792	42.1%
Mercedes-Benz SL (2004)	21 years in 2025	17.0%	1,756	42.1%
Mercedes-Benz M-Class (2004)	21 years in 2025	41.4%	1,010	42.1%

More on the Mercedes-Benz A-Class

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.

Found one you might buy? Vet the specific car.

These figures describe 2004 Mercedes-Benz A-Class cars as a group, not any one car. The VetTheCar Buying Report looks at the car you are buying: its MOT history, what similar cars did next, and what to ask the seller.

See an example Buying Report All car tools

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

Car tax and clean air zone rules are summarised from GOV.UK and Transport for London guidance. They are general rules and are not drawn from the MOT data.