Audi
1,579 MOT tests analysed. sits above the UK fleet average — here's where A6 S Lne Blk ED 40 Tdi Quat SAs pass, fail, and end up on the retest sheet.
That's 13.1 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
90.6%
Pass-after-fix
1.3%
Fail
7.3%
Avg miles
41,659
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 · 1,579 tests
Pass rate is broadly flat across the cohorts — new and old A6 S Lne Blk ED 40 Tdi Quat SA examples track each other at the test bay.
Pass
90.8%
Fail
7.9%
PRS
0.4%
Avg mileage at test
47,751 mi
Pass
90.4%
Fail
6.6%
PRS
2.4%
Avg mileage at test
34,825 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.
The picture
Across 1,579 MOT tests, the A6 S Lne Blk Ed 40 Tdi Quat Sa returns 90.6% 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 41,659, 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.
Filter failures:
Hide categories
Tick a category to hide it from rankings sitewide. Saved in this browser only.
Tyre tread depth not in accordance with the requirements
45 occurrences · 2.8% of tests
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
32 occurrences · 2.0% of tests
A tyre seriously damaged
21 occurrences · 1.3% of tests
Wiper blade defective
19 occurrences · 1.2% of tests
Number plate does not conform to the specified requirements
9 occurrences · 0.6% of tests
Engine MIL illuminated indicating a malfunction
8 occurrences · 0.5% of tests
A headlamp cleaning device inoperative in the case of LED or gas discharge systems (HID)
7 occurrences · 0.4% of tests
a brake lining or pad worn below 1.5mm
5 occurrences · 0.3% of tests
Obligatory mirror or device slightly damaged or loose
4 occurrences · 0.3% of tests
Smoke opacity levels exceed the manufacturer's specified limit
4 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
£95–£175
If every one of this A6 S Lne Blk ED 40 Tdi Quat 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 →
Try the calculator
Build your own retest budget.
Year-band analysis
First-time MOT pass rate split by registration band. Pass rates barely move across bands here, so the year you buy Audi A6 S Lne Blk ED 40 Tdi Quat SA makes little measurable difference to MOT outcomes.
Best band to buy
90.8%
2018–2020 registration
the 2018–2020 band climbs to 90.8% — a 0.4-point improvement. Failures here are mostly wear items: tread depth below requirements of 1.6mm, blade defective — the structural issues that drag down older examples don't appear in the top-10 for this band.
Band to be cautious about
90.4%
2021+ registration
On the 2021-on band, the data shows a 90.4% pass rate against a fleet average of 90.8% on the newer band. The main culprits logged at test: damaged but not adversely affecting driver's view, has a cut in excess of the…, and tread depth below requirements of 1.6mm. Average mileage on test for this band is 34,825 miles — high-mileage wear items are a recurring theme.
Best band to buy: 2018-2020 (90.8% first-time pass). Worst band to avoid: 2021+ (90.4% pass). That's a 0.4-point spread across 742 older tests and 837 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
Bosch Aerotwin wiper blades
Cheap wipers fail the test on smear streaks. Bosch Aerotwins last a winter and clear a screen properly.
Search Amazon UK
Item 03 · 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
My Motor World · affiliate
Affiliate links — small commission, no extra cost to you.
Summit
Summit ADRG-215 Audi Replacement Stick-On Tinted Mirror Glass RHS
£9.89
View at My Motor World →
Summit
Summit ADRG-216 Audi Replacement Stick-On Tinted Mirror Glass LHS
£14.29
View at My Motor World →
Draper Expert
Draper Expert Oil Filter Socket for Audi, BMW, Mercedes-Benz, Porsche and VW
£18.69
View at My Motor World →
Draper Expert
Draper Expert Audi/VW Drain Plug Key, 1/2" Sq. Dr.
£21.99
View at My Motor World →
Click Mechanic · affiliate
Affiliate links — small commission, no extra cost to you.
Mobile mechanic · UK-wide
Book a mechanic at your door.
Fixed-price quotes upfront. No garage needed. Click Mechanic sends a vetted local mechanic to you — home, work, or roadside.
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 Lne Blk ED 40 Tdi Quat 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.
