2021 Audi A6 S Line Black Ed 40 Sa — MOT failures & pass rate

Across 1,342 MOT tests analysed for the 2021 Audi A6 S Line Black Ed 40 Sa, the most common recorded failure areas were tyres, emissions & environmental and brakes. Its pass rate of 90.1% was below the average for cars of a similar age (91.3%).

Pass rate

1,342

MOT tests analysed

9.9%

Fail rate

worse than

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 A6 S Line Black Ed 40 Sa
#	Category	% of tests affected	Tests
1	Tyres	5.4%	72
2	Emissions & environmental	2.8%	38
3	Brakes	1.6%	21
4	Visibility	1.3%	17
5	Lighting & signalling	1.3%	17
6	Suspension	0.7%	9

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 A6 S Line Black Ed 40 Sa
#	Failure item	Times recorded
1	Tread depth	61
2	Malfunction indicator lamp	35
3	Brake pads	22
4	Headlamp aim	16
5	Registration plates	11
6	Wipers	10

Top advisory categories

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

Most common MOT advisories — 2021 Audi A6 S Line Black Ed 40 Sa
#	Category	% of tests with advisory	Tests
1	Tyres	21.6%	290
2	Brakes	9.5%	127
3	Other defects	7.1%	96
4	Suspension	4.2%	56
5	Visibility	3.9%	52
6	Emissions & environmental	0.6%	8

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 A6 S Line Black Ed 40 Sa
Mileage band	Tests	Fail rate
0-30k	398	9.8%
30-60k	752	9.7%
60-90k	162	11.7%

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 A6 S Line Black Ed 40 Sa
Dataset year	Tests	Fail rate
2023	35	8.6%
2024	673	10.3%
2025	626	9.7%

What to check before buying a 2021 A6 S Line Black Ed 40 Sa

Before buying a 2021 Audi A6 S Line Black Ed 40 Sa, focus on the areas it most often fails on. Tyres accounted for 5.4% of tests for this year.

Tyres (5.4% 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.
Emissions & environmental (2.8% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
Brakes (1.6% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.

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 A6 S Line Black Ed 40 Sas pass their MOT?

90.1% of the 1,342 2021 Audi A6 S Line Black Ed 40 Sa MOT tests in this dataset passed — a 9.9% fail rate.

What is the most common MOT failure on a 2021 Audi A6 S Line Black Ed 40 Sa?

Tyres, recorded in 5.4% of tests, followed by emissions & environmental (2.8%).

Does the 2021 A6 S Line Black Ed 40 Sa get worse with mileage?

Its MOT fail rate rises from 9.8% in the 0-30k band to 11.7% in the 60-90k band.

Methodology & source. Based on 1,342 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.