Audi
3,397 MOT tests analysed. sits above the UK fleet average — here's where A6 S Line Black ED 40 Tdi SAs pass, fail, and end up on the retest sheet.
That's 13.5 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
91.0%
Pass-after-fix
1.4%
Fail
6.9%
Avg miles
42,059
Pass + Pass-after-fix + Fail = 100%
Diesel cars registered from September 2015 generally meet Euro 6 — compliant in London ULEZ, Birmingham CAZ, Bristol CAZ, and Glasgow LEZ.
Performance by cohort
2 year bands · 3,397 tests
Pass rate drops 2.5 points across the cohorts — recent A6 S Line Black ED 40 Tdi SA examples are doing worse than the early cars at the same tested age.
Pass
91.9%
Fail
6.1%
PRS
1.1%
Avg mileage at test
46,221 mi
Pass
89.5%
Fail
8.1%
PRS
1.8%
Avg mileage at test
35,513 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.
The picture
Across 1,134 MOT tests, the A6 S Line Black Ed 40 Tdi Sa returns 91.5% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is tyre tread under the limit. Windscreen damage and a seriously damaged tyre round out the top three. Average tested mileage sits at 35,889, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.
ABI Insurance Group
A high-group car — insurance costs will be significantly above average. Lower groups cost less to insure; UK fleet average is around Group 22.
Source: ABI Group Rating Panel · administered by Thatcham Research · groups cover standard variants; performance trims may sit higher. Browse all insurance groups →
32–46
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Tyre tread depth not in accordance with the requirements
106 occurrences · 3.1% of tests
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
74 occurrences · 2.2% of tests
A tyre seriously damaged
35 occurrences · 1.0% of tests
Number plate does not conform to the specified requirements
28 occurrences · 0.8% of tests
a brake lining or pad worn below 1.5mm
22 occurrences · 0.6% of tests
Reflector defective or damaged by up to 50% of the reflecting surface
16 occurrences · 0.5% of tests
Wiper blade defective
15 occurrences · 0.4% of tests
Wiper blade missing or obviously not clearing the windscreen
14 occurrences · 0.4% of tests
Engine MIL illuminated indicating a malfunction
13 occurrences · 0.4% of tests
A tyre cords visible or damaged
10 occurrences · 0.3% of tests
Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.
Worst-case fix budget · top 3 failures
£155–£290
If every one of this A6 S Line Black ED 40 Tdi SA's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →
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Build your own retest budget.
Year-band analysis
First-time MOT pass rate split by registration band. A 2.5-point gap between bands is modest — the year you buy Audi A6 S Line Black ED 40 Tdi SA makes a small but real difference to MOT outcomes.
Best band to buy
91.9%
2018–2020 registration
the 2018–2020 band climbs to 91.9% — a 2.5-point improvement. Failures here are mostly wear items: tread depth below requirements of 1.6mm, damaged but not adversely affecting driver's view — the structural issues that drag down older examples don't appear in the top-10 for this band.
Band to be cautious about
89.5%
2021+ registration
On the 2021-on band, the data shows a 89.5% pass rate against a fleet average of 91.9% on the newer band. The main culprits logged at test: tread depth below requirements of 1.6mm, damaged but not adversely affecting driver's view, and has a cut in excess of the…. Average mileage on test for this band is 35,513 miles — high-mileage wear items are a recurring theme.
Best band to buy: 2018-2020 (91.9% first-time pass). Worst band to avoid: 2021+ (89.5% pass). That's a 2.5-point spread across 1,318 older tests and 2,079 newer ones — year of build makes a material difference on this model.
Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.
Item 01 · Amazon UK
Digital tyre-tread depth gauge
Five quid for a gauge beats £150 for a retest. UK MOT minimum is 1.6mm — most testers fail anything below 2mm to be safe.
Search Amazon UK
Item 02 · Amazon UK
MOT-spec replacement number plate
Faded or non-standard plates fail outright. Replacements take ten minutes online with V5C details.
Search Amazon UK
Item 03 · Amazon UK
Brake pad measurement gauge
Testers fail pads under 1.5mm. A wear gauge tells you if you've got two months left or two weeks.
Search Amazon UK
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Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.
If you own an A6 S Line Black ED 40 Tdi SA and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.
