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MOT fail rates by first-use year

2008 Mercedes-Benz B-Class MOT fail rate and common faults

How Mercedes-Benz B-Class cars first used in 2008 did at their MOTs from 2022 to 2025, against all cars of the same age. From 14,936 DVSA MOT tests of these cars. First use is usually the date the car was first registered.

MOT data updated

At 17 years, tested in 2025

MOT fail rate at age 17 (n=3,099)44.5%
All cars at 17 years (n=4,040,458)43.1%
Difference+1.4 pts
MOT tests of 2008 cars, 2022 to 202514,936

What stands out

  • In 2025, at 17 years old, Mercedes-Benz B-Class cars first used in 2008 failed 44.5% of MOTs (3,099 tests), 1.4 points above the 43.1% for all cars that age.
  • From 2022 to 2025, as these cars went from 14 to 17 years old, the fail rate moved from 42.8% to 44.5%.
  • Mercedes-Benz B-Class cars first used a year earlier, in 2007, failed 44.2% at the same age of 17 years (2,735 tests, in 2024).
  • The most common fail item that is not a wear item, for the Mercedes-Benz B-Class at 17 years, is driveshaft CV boot split, at 9.8 per 100 MOTs (all cars: 3.2).

MOT fail rate by test year

Mercedes-Benz B-Class cars first used in 2008: 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 yearAgeMOT fail rateTests (n)All carsDifference
202214 years42.8%4,30740.3%+2.5 pts
202315 years43.2%3,96741.6%+1.6 pts
202416 years45.2%3,56342.6%+2.7 pts
202517 years44.5%3,09943.1%+1.4 pts

Most common faults at 17 years

These figures cover all Mercedes-Benz B-Class MOTs at 17 years: cars first used 2005 to 2008, tested 2022 to 2025 (n=8,986). 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 itemPer 100 MOTsAll cars
Driveshaft CV boot split9.83.2
Coil spring broken6.63.5
Suspension ball joint worn5.12.4
Washers: provides insufficient washer liquid Wear4.72.4
Brake light not working Wear4.14.0
Rigid brake pipes: excessively corroded4.01.9
Handbrake too weak3.42.7
Dipped headlight not working Wear2.82.2
Engine warning lamp at the petrol emissions check: not working or showing a fault2.62.2
Side/position light not working Wear2.55.8

Per 100 of the MOTs above (n=8,986). A test with two items counts once for each.

Advisories

AdvisoryPer 100 MOTsAll cars
Rigid brake pipes: corroded, covered in grease or other material21.110.5
Tyre tread close to the legal limit or worn on the edge Wear16.617.9
Brake discs: worn, pitted or scored, but not seriously weakened14.011.3
Drive shaft joints: constant velocity boot severely deteriorated11.93.9
Tyre condition: slightly damaged/cracking or perishing Wear11.19.6
Brake pads wearing thin Wear8.26.6
Coil spring: corroded6.87.5
Shock absorber misting oil6.14.1
Flexible brake hoses: slightly deteriorated6.01.6
Non-component advisories: Fuel Pipe/s corroded5.20.6

Per 100 of the MOTs above (n=8,986). A test with two items counts once for each.

Fuel type at 17 years

These figures cover all Mercedes-Benz B-Class MOTs at 17 years: cars first used 2005 to 2008, tested 2022 to 2025 (n=8,986). Each fuel is set against all cars of the same fuel and age. Fuels with fewer than 1,000 tests are not shown.

FuelShare of testsMOT fail rateTests (n)All cars, same fuelMedian mileage
Petrol51.9%42.4%4,66743.2%91,636 miles
Diesel48.1%45.7%4,31943.2%108,390 miles

Fail rate by mileage at 17 years

These figures cover all Mercedes-Benz B-Class MOTs at 17 years: cars first used 2005 to 2008, tested 2022 to 2025 (n=8,986). At 17 years, Mercedes-Benz B-Class cars at 120,000 to 150,000 miles failed more often (48.6%, n=1,725) than those at 60,000 to 90,000 miles (40.2%, n=2,494). Bands with fewer than 1,000 tests are not shown.

Mileage at testMOT fail rateTests (n)All cars
60,000 to 90,000 miles40.2%2,49441.7%
90,000 to 120,000 miles47.1%3,06246.2%
120,000 to 150,000 miles48.6%1,72547.1%

Car tax rules for a 2008 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

  • Petrol cars first registered from 2006 usually meet Euro 4, the petrol standard for the London ULEZ, so they usually do not pay the daily charge.
  • Diesel cars first registered before September 2015 usually do not meet Euro 6, so a 2008 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 B-Class

Other Mercedes-Benz models first used in 2008

ModelAge at testMOT fail rateTests (n)All cars
Mercedes-Benz C-Class (2008)17 years in 202535.8%13,30443.1%
Mercedes-Benz A-Class (2008)17 years in 202541.8%6,14643.1%
Mercedes-Benz E-Class (2008)17 years in 202529.9%3,87843.1%
Mercedes-Benz SLK (2008)17 years in 202531.9%3,13743.1%
Mercedes-Benz CLK (2008)17 years in 202539.0%2,46143.1%
Mercedes-Benz M-Class (2008)17 years in 202531.6%1,92643.1%
Mercedes-Benz CLC (2008)17 years in 202542.5%2,02543.1%
Mercedes-Benz CLS (2008)17 years in 202530.9%1,18243.1%

More on the Mercedes-Benz B-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 2008 Mercedes-Benz B-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.