MOT fail rates by first-use year

2021 Mercedes-Benz GLA MOT fail rate and common faults

How Mercedes-Benz GLA cars first used in 2021 did at their MOTs from 2024 to 2025, against all cars of the same age. From 18,565 DVSA MOT tests of these cars. First use is usually the date the car was first registered.

MOT data updated 28 September 2026

At 4 years, tested in 2025

MOT fail rate at age 4 (n=9,083)8.4%

All cars at 4 years (n=8,699,937)13.4%

Difference−5.0 pts

MOT tests of 2021 cars, 2024 to 202518,565

What stands out

In 2025, at 4 years old, Mercedes-Benz GLA cars first used in 2021 failed 8.4% of MOTs (9,083 tests), 5.0 points below the 13.4% for all cars that age.
From 2024 to 2025, as these cars went from 3 to 4 years old, the fail rate moved from 8.8% to 8.4%.
Mercedes-Benz GLA cars first used a year earlier, in 2020, failed 9.0% at the same age of 4 years (9,249 tests, in 2024).

MOT fail rate by test year

Mercedes-Benz GLA cars first used in 2021: 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
2024	3 years	8.8%	9,482	12.1%	−3.2 pts
2025	4 years	8.4%	9,083	13.4%	−5.0 pts

Most common faults at 4 years

These figures cover all Mercedes-Benz GLA MOTs at 4 years: cars first used 2018 to 2021, tested 2022 to 2025 (n=51,974). 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
Tyre tread below 1.6 mm Wear	1.3	1.4
Tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords Wear	1.3	1.5
Brake pads under 1.5 mm Wear	1.1	1.3
Wipers not clearing screen Wear	1.0	2.5
Washers: provides insufficient washer liquid Wear	0.6	0.7
Tyre condition: has a bulge, caused by separation or partial failure of its structure Wear	0.6	0.4
Brake pads: worn down to wear indicator Wear	0.6	0.2
Headlamp aim: too low Wear	0.5	0.6
Tyre with cords exposed Wear	0.4	0.9
Headlight aimed too high Wear	0.4	0.6

Per 100 of the MOTs above (n=51,974). A test with two items counts once for each.

Advisories

Advisory	Per 100 MOTs	All cars
Tyre tread close to the legal limit or worn on the edge Wear	12.0	12.4
Brake pads wearing thin Wear	7.7	6.9
Tyre condition: slightly damaged/cracking or perishing Wear	5.9	6.3
Non-component advisories: Nail in tyre	2.7	2.1
Non-component advisories: Child Seat fitted not allowing full inspection of adult belt	2.6	2.2
Brake discs: worn, pitted or scored, but not seriously weakened	2.4	5.2
Brake discs: worn, but not excessively	2.2	1.7
Tyre tread close to the legal limit, under the 1.0 mm rule Wear	1.8	1.8
Tyre condition: has a cut but not deep enough to reach the ply or cords Wear	1.4	1.8
Wipers: blade defective Wear	1.3	1.3

Per 100 of the MOTs above (n=51,974). A test with two items counts once for each.

Fuel type at 4 years

These figures cover all Mercedes-Benz GLA MOTs at 4 years: cars first used 2018 to 2021, tested 2022 to 2025 (n=51,974). 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	70.4%	10.0%	36,564	12.0%	26,582 miles
Diesel	25.8%	9.4%	13,390	16.5%	31,502 miles
Hybrid	3.9%	7.9%	2,020	11.3%	32,269 miles

Fail rate by mileage at 4 years

These figures cover all Mercedes-Benz GLA MOTs at 4 years: cars first used 2018 to 2021, tested 2022 to 2025 (n=51,974). At 4 years, Mercedes-Benz GLA cars at 60,000 to 90,000 miles failed more often (15.1%, n=1,690) than those at under 30,000 miles (8.0%, n=28,977). Bands with fewer than 1,000 tests are not shown.

Mileage at test	MOT fail rate	Tests (n)	All cars
Under 30,000 miles	8.0%	28,977	10.2%
30,000 to 60,000 miles	11.6%	20,927	15.5%
60,000 to 90,000 miles	15.1%	1,690	20.7%

Car tax rules for a 2021 car

Cars first registered from 1 April 2017 pay a first-year rate set by CO2 emissions, then the standard rate each year. A petrol, diesel or hybrid car with a list price over £40,000 also pays the expensive car supplement for five years, from the second tax payment.

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 from September 2015 usually meet Euro 6, the diesel standard for the London ULEZ, so they usually do not pay the daily charge.
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 GLA

2020 Mercedes-Benz GLA 2022 Mercedes-Benz GLA

Other Mercedes-Benz models first used in 2021

Model	Age at test	MOT fail rate	Tests (n)	All cars
Mercedes-Benz A-Class (2021)	4 years in 2025	10.3%	30,396	13.4%
Mercedes-Benz CLA (2021)	4 years in 2025	13.9%	10,130	13.4%
Mercedes-Benz C-Class (2021)	4 years in 2025	12.9%	6,770	13.4%
Mercedes-Benz E-Class (2021)	4 years in 2025	12.1%	6,836	13.4%
Mercedes-Benz GLC (2021)	4 years in 2025	9.2%	6,650	13.4%
Mercedes-Benz GLE (2021)	4 years in 2025	12.4%	4,915	13.4%
Mercedes-Benz B-Class (2021)	4 years in 2025	8.2%	1,820	13.4%

More on the Mercedes-Benz GLA

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 2021 Mercedes-Benz GLA 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.