2021 Audi A4 S Ln Blk Ed 40 Mhev Sa — MOT failures & pass rate

Across 945 MOT tests analysed for the 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa, the most common recorded failure areas were tyres, lighting & signalling and visibility. Its pass rate of 91.2% was in line with the average for cars of a similar age (91.3%). Higher-mileage examples failed more often — 14.7% in the 60-90k group versus 7.4% in the 0-30k group.

Pass rate

945

MOT tests analysed

8.8%

Fail rate

in line with

vs cars of similar age

3.4

Avg age at test (yrs)

How it compares

Fail rate for this model-year against the segment and national averages for cars of a similar age.

Top failure categories

Most common MOT failure areas — 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa
#	Category	% of tests affected	Tests
1	Tyres	7.7%	73
2	Lighting & signalling	1.2%	11
3	Visibility	0.7%	7
4	Brakes	0.7%	7
5	Other defects	0.2%	2
6	Seat belts & restraints	0.2%	2

Percentage of tests with at least one failure recorded in each category.

Most common specific failures

The exact components most often recorded as failures — more specific than the categories above.

Most frequently recorded failure items — 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa
#	Failure item	Times recorded
1	Tread depth	30
2	Headlamp aim	16
3	Registration plates	4
4	Brake pads	4
5	Wipers	3
6	Tyre pressure monitoring system	3

Top advisory categories

Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.

Most common MOT advisories — 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa
#	Category	% of tests with advisory	Tests
1	Tyres	22.9%	216
2	Other defects	8.7%	82
3	Suspension	4.1%	39
4	Brakes	4.1%	39
5	Visibility	2.1%	20
6	Road wheels	0.6%	6

Failure rate by mileage

Higher-mileage cars tend to fail more — often the most useful guide to real condition.

MOT fail rate by recorded mileage band.

Fail rate by recorded mileage — 2021 A4 S Ln Blk Ed 40 Mhev Sa
Mileage band	Tests	Fail rate
0-30k	497	7.4%
30-60k	409	9.8%
60-90k	34	14.7%

Failure rate by age

How this model-year's MOT fail rate climbs as the cars get older.

Trend over time

Fail rate by dataset year — 2021 A4 S Ln Blk Ed 40 Mhev Sa
Dataset year	Tests	Fail rate
2023	32	6.3%
2024	458	8.3%
2025	455	9.4%

What to check before buying a 2021 A4 S Ln Blk Ed 40 Mhev Sa

Before buying a 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa, focus on the areas it most often fails on. Tyres accounted for 7.7% of tests for this year.

Tyres (7.7% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
Lighting & signalling (1.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
Visibility (0.7% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.

Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.

Frequently asked questions

How many 2021 Audi A4 S Ln Blk Ed 40 Mhev Sas pass their MOT?

91.2% of the 945 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa MOT tests in this dataset passed — a 8.8% fail rate.

What is the most common MOT failure on a 2021 Audi A4 S Ln Blk Ed 40 Mhev Sa?

Tyres, recorded in 7.7% of tests, followed by lighting & signalling (1.2%).

Does the 2021 A4 S Ln Blk Ed 40 Mhev Sa get worse with mileage?

Its MOT fail rate rises from 7.4% in the 0-30k band to 14.7% in the 60-90k band.

Methodology & source. Based on 945 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.