Audi S4 — MOT statistics 2024

The Audi S4 failed 15.19% of 2,436 first MOT attempts in 2024 ("first-time", excluding retests). Adjusted for the age of the fleet, its initial-failure ratio is 54.2 (100 = expected for its age profile). This car fails its MOT about 46% less often than expected for its age. Small sample — treat with care.

Age-adjusted peer: Toyota GR Yaris (index 54.7) — the two published results are 0.5 index points apart.

Audi S4 common problems: what actually fails the MOT

Lamps, reflectors and electrical equipment are well below the reference at 9.9 per 100 tests, against 23.4 per 100 tests across UK vehicles of the same ages.

higher bar = fails more oftenrate per 100 tests

family vs national — matched to UK vehicles of the same ages — top component groups, per 100 tests. Legend: This family · National avg. Combined labels: family / national average. A gap here reflects how these vehicles are driven, used and maintained as well as how they were built — an MOT defect is a test outcome, not a breakdown.

Named defects ranked by how much more often they appear than the national average — not by raw rate.

Audi S4 MOT advisories: what gets flagged

Tyres are highest at 30.8 per 100 tests; Body & structure are lowest at 3.2 per 100 tests — the gap is 27.6 per 100 tests.

higher bar = flagged more oftenadvisory items per 100 initial tests

Advisories are wear the tester noted but didn't fail — what will need money soon.

Tyres, brakes and suspension: Audi S4 against cars of the same age

Failing items per 100 initial tests, 2019-2024. The comparison group is every petrol or diesel car tested at the same age, so weight and drivetrain show up rather than fleet age.

If a car like this fails, does it fail again?

A failure rate does not say whether a failure is a one-off or the start of something. This follows the same vehicles into their next ordinary MOT a year later — retests after a repair are excluded, because they follow a failure by definition. 2019-2024.

A failed test raises next year's chance of failing again by 4.8 percentage points. The failure most likely to come back is lamps, reflectors and electrical equipment — 31.7% of those vehicles fail again next year. Some of this is the vehicle and some is the owner: a car that was let go once tends to be let go again. One caveat: a car that fails may be sold or scrapped rather than tested again, so these figures describe the vehicles that came back.

Adjusted for how much these are actually driven

The headline index adjusts for the fleet's age. Wear, though, follows mileage: a three-year-old taxi and a three-year-old garage queen sit in the same age band. These two rows compare every car with vehicles of the same age, and then with vehicles of the same age and the same annual mileage, 2019-2024, on 11,138 tests. Both stand on the six-year corpus so they are measured on identical data — compare them with each other, not with the headline index above, which is measured on 2024 alone.

Mileage changes little here (-1.7 points): this fleet is driven about as much as the vehicles it is compared with. One limit to keep in mind: mileage is partly a result of how often a car breaks down — one that spends weeks in the workshop covers fewer miles — so the mileage-matched figure can understate a real weakness. Tests with no usable odometer reading are left out of it.

How the Audi S4 compares with cars of its own age and size

Not against the whole fleet — against cars of the same size class tested at the same age, 2019-2024.

Raw first-time failure rates within each age, so fleet age cannot flatter either side. A positive difference means this model fails more often than its own class at that age.

How does the Audi S4 perform as it gets older?

The S4 at age 13 is well below the reference at 15.0%, against 38.2% for all vehicles of the same age.

higher = larger sharecompare shares in percentage points

Chart axes: car age, years · failure-rate scale 0–47%.

Takeaway: solid line: this family; dashed: all cars.

Audi S4 petrol vs diesel: which ages best

Petrol is highest at 20.5%; Diesel is lowest at 8.3% — the gap is 12.2 percentage points.

higher = larger sharecompare shares in percentage points

Chart sample sizes: n=1,383 · n=1,051.

How dangerous are Audi S4 MOT failures?

Major defects are well below the reference at 30.5 per 100 tests, against 52.8 per 100 tests nationally.

higher bar = fails more oftenrate per 100 tests

Chart values: Minor 14.3 · Major 30.5 · Dangerous 8.0.

Per 100 tests on this family. National average: Minor 14.2 · Major 52.8 · Dangerous 11.2 per 100.

Does the month of an Audi S4 MOT matter?

Jul is highest at 22.2%; Dec is lowest at 15.2% — the gap is 7.0 percentage points.

higher = larger sharecompare shares in percentage points

Chart scale: 14%–33%.

bars: Audi S4 · dashed: all class-4 cars

Takeaway: the spread between best and worst month is 7.0 percentage points — noticeable seasonality. Seasonality partly reflects registration-date clustering, not weather.

Before reading the shape: most of it is not about cars. Britain changes its registration plates twice a year, and 18.9% of these cars were first registered in March with another17.1% in September — 36% in two months against the 17% an even spread would give. An MOT falls due three years after first registration, so the buying calendar becomes the testing calendar. That shapes how many cars are tested each month — not how often they fail: the busiest months here are not the worst ones, so read the failure line on its own and the volume behind it separately.

Audi S4 average mileage by age

At age 15, the middle half of S4s runs from 82,725 miles to 114,793 miles, against 100,583 miles as the median.

further right = more milesmedian is the typical car; band is p25–p75

Chart axes: car age, years · odometer scale 0–148k mi.

Does high mileage mean more Audi S4 MOT failures at the same age?

Within the same age group, split by odometer (2024 MOTs), so this separates wear from age: at ages 3–5, 7.2% of those with under 40,000 miles failed first time versus 18% of those with 70,000–100,000 miles.Inside this age group, higher mileage goes with more failures.

line: median · band: middle half of the fleet (p25–p75)

A typical 15-year-old S4 has ~100,583 miles on the clock. Much more — ask why; much less — check for gaps in the MOT history.

Where in Britain the Audi S4 fails its MOT most

Brighton area is highest at 34.3%; Stockport area is lowest at 11.3% — the gap is 23.0 percentage points.

higher = larger sharecompare shares in percentage points

Toughest areas	% failing	vs model overall
Brighton (BN)	34.29%	+14.6 pp
Bristol (BS)	31.31%	+11.6 pp
York (YO)	30.43%	+10.8 pp
Bournemouth (BH)	29.52%	+9.9 pp
Ipswich (IP)	28.3%	+8.6 pp

Easiest areas	% failing	vs model overall
Stockport (SK)	11.29%	-8.4 pp
Newcastle (NE)	11.72%	-7.9 pp
Birmingham (B)	12.79%	-6.9 pp
Bradford (BD)	12.94%	-6.7 pp

Every dot is a postcode area — size = how many were tested there, colour = share failing. These figures are not age-adjusted: coastal and rural areas often run older fleets and salted roads, so higher raw fail rates do not automatically mean a worse local stock of this model.

Map labels: Scotland · N. England · Wales · London · S. West. Colour scale: 13%–31% failing.

Audi S4 survival: which cars are still on the road

By age 19 is well below the reference at 40.5%, against 100.0% at the ages 4–6 reference level.

higher = larger sharecompare shares in percentage points

Chart axes: car age, years · survival vs ages 4–6 · scale 0–105%.

By age 17, only about 64% as many cars of this family present for MOT as at ages 4–6 (reference n≈929); survivors still fail at 26.6% vs 8.5% at age 4. Older cars that still appear are a selected subset — weaker ones have already left.

How many miles does an Audi S4 last?

100,000+ miles is highest at 33.0%; 150,000+ miles is lowest at 7.1% — the gap is 25.9 percentage points.

higher = larger sharecompare shares in percentage points

Of 11,198 tests of this family with a usable odometer in 2024, 33.0% had reached 100k miles, 7.1% had reached 150k miles. This is a cross-section of cars still presenting for MOT, not a full birth cohort.

How many years is an Audi S4 likely to last?

Bought at age 10 is highest at 7.7 years; Bought at age 15 is lowest at 2.1 years — the gap is 5.6 years.

bigger number = longer remaining lifeyears on the observed survival curve

estimateEstimate only — not a warranty: a typical 10-year-old example of this family has at least 7.7 expected years of further MOT-present life. The curve is observed only until age 17, so the true figure is likely higher.

Audi S4 faults that come together

Emissions & leaks + Seatbelts & SRS stand out at 8.52×, against 1.00× if the faults were independent.

above 1.0× = more than expectedbelow 1.0× = less

Defects in «Noise, emissions and leaks» and «Seat belts and supplementary restraint systems» appear together 8.52× more often than chance (21 co-occurrences in the same test; 55 pairs compared).

Lift = how many times more often both groups appear on the same test than if independent. A pair is listed from 5 tests with both faults; the lift is shown from 20, and called above chance only when its 95% interval excludes 1 (see rough estimates).

Is low mileage better for an Audi S4?

Cars driven under 5,000 miles a year is well below the reference at 12.7%, against 24.6% for cars driven 8,000–12,000 miles a year.

higher = larger sharecompare shares in percentage points

At matched ages 5–14, cars averaging under 5k miles/year fail at 12.7% vs 24.6% for 8–12k miles/year — 11.9 pp lower (n_low=543, n_normal=1,723). In this family low annual use is associated with fewer MOT fails, not more — the ‘garage queen’ penalty is not visible in overall fail rates.

Audi S4 MOT repair costs

The MOT-failure repair budget per test runs from £51.36 to £97.58, against £54.85 for the test itself.

bigger number = costs morepounds per test, MOT-failing faults only

Multiply how often each component fails on this model by what that repair usually costs, and you get the amount an owner should expect to budget per test for MOT-failing faults only — roughly £51 to £98, on top of the test fee itself. It is a budgeting figure, not a quote: the spread between a set of pads and a set of discs is most of the range.

Prices are modal quotes from a hand-kept catalogue of published UK garage guides — we do not scrape the booking sites, their terms forbid it, so this list is short and updated by hand with a source and date against each line. Each line prices one typical repair in that group, not a full remedy, and only groups our catalogue actually covers are counted. The contrast worth noticing is the second card: the legal maximum for the test has been £54.85 since 2010, while the repairs it uncovers have followed inflation the whole time.

For scale from a different direction: Warrantywise, which sees used-car warranty claims rather than test failures, puts the average claim at £2,052 across the ten highest-claim models it ranks and £539 for Honda, the lowest-claim make in its index (Warrantywise index 2026, 1.6 million claims, cars aged 3–15). Those sit an order of magnitude above the figures in this table, and the gap is the point: a warranty claim is a gearbox or an engine, which almost never fails an MOT, while the faults that do fail one are corrosion, lamps and tyres, which no warranty pays for. The two numbers answer different questions and neither replaces the other.

Audi S4 running costs for a fleet

Vehicles failing at age 19 stand out at 27.0%, against 10.0% at age 5, tested in the same year.

higher = larger sharecompare shares in percentage points

No single year stands out as the point where this model starts costing more: the year-to-year steps in its failure rate are too small or rest on too few tests to name one (D1 rule: a step is named only with at least 2,000 tests on both sides and a jump above 3 percentage points).

Repair spend uses the same modal prices as the section above, so it inherits the same limits: one typical repair per component group, not a full remedy. Downtime is the gap between the failed test and the passed re-test, which is the window a vehicle is legally off the road.

Audi S4 rust problems: where they corrode

Age-standardised corrosion susceptibility is well below the reference at 0.17×, against 1.00× for the national age-standardised rate.

above 1.0× = rusts more than averagebelow 1.0× = rusts less

This Audi S4 fails on corrosion much less often than average once age is held constant, and its owners live in areas that are saltier than most for the models we publish. Both point the same way and reinforce each other: it resists corrosion even though its owners live in saltier areas than most.

Corrosion is the one failure mode that is as much about geography as about the car. We keep the two apart on purpose: a model can look rusty simply because it is popular in Scotland, and a model can look clean simply because it is bought in Surrey. Blending them into a single score would hide which of the two is doing the work.

Exposure is this model's tests weighted by an area corrosion index built from frost days, salt load and distance to the coast — the composite validated at r = 0.42 against corrosion defects we actually record. It is published as a rank, not a raw score, because every mainstream model skews towards low-corrosion areas for the simple reason that most of Britain's cars are in the south. Susceptibility is standardised to the national age profile, so an old fleet does not get labelled a rusty model.

Does an Audi S4 advisory become a failure?

Suspension is highest at 16.2%; Brakes are lowest at 5.5% — the gap is 10.7 percentage points.

higher = more likelypercentage is the observed transition probability

chance the same component fails at the next MOT, given an advisory now

This is the question an advisory note actually raises, and it needs six years of test history to answer. We followed the same vehicles from one MOT to the next across 2019–2024 and measured how often a component that was merely advised came back as a genuine failure at the next test.

Read it as a budgeting horizon, not a prophecy: the most likely component above turns into a failure for about 16 in 100 cars, and the median gap is 12 months and roughly 3,329 miles. The rest were repaired, sold, scrapped, or simply held. Rows with fewer than 500 tracked advisories are not shown.

What will fail next on an Audi S4?

Suspension after a advisory at age 15-19 is highest at 19.2%; Brakes after a passed at age 3-5 are lowest at 1.6% — the gap is 17.6 percentage points.

higher = more likelypercentage is the observed transition probability

The same chains, cut differently: given a car's age and how its last test went, which component most often causes trouble at the following one.

The pattern that repeats across every family: a failure at one test roughly doubles the chance of a failure on the same component at the next one, and an advisory sits about half-way between a clean pass and a failure. Age bands in years; probabilities are per car, not per defect item.

Audi S4 ownership: what six years of MOTs show

The ten-day re-test pass rate is highest at 63.4%; The later re-test pass rate is lowest at 4.9% — the gap is 58.4 percentage points.

higher = larger sharecompare shares in percentage points

Failing is usually a same-week event, not a disaster. Of 1,578 failures followed through to their re-test, 31.69% were repaired and passed the same day and 63.37% within ten days; the median gap is 1 day. 3,410 defect items were cleared in the process.

Per mile driven, not per year. Dividing failures by the miles that actually went onto the odometers between consecutive tests gives 0.38 failures per 10,000 miles, on a median of 4,194 miles a year across 2,592 chains. This is the number to compare between models — an annual rate quietly rewards cars that barely leave the drive.

Two populations hide inside one model. 40.61% of these cars strung together three or more tests with nothing recorded at all, while 23.14% carried the same advisory three times or more — the same fault, noted, ignored, noted again. When you buy used you are buying one of those two histories, and the MOT record shows which.

Odometer anomalies: 1.35% of 2,593 chains show a reading lower than the previous test, with a median drop of 34,133 miles. We call this an anomaly and not fraud on purpose — instrument swaps, imports, unit mix-ups and keying errors all land in the same bucket. Obvious typos (drops under 100 miles or over 90% of the reading) are already excluded.

Audi S4 technical service bulletins: what dealers are told

US market, Audi S4, model years 2015–2021 only. A count of bulletins, not a UK failure rate.

NHTSA manufacturer communications are 1,692.

bigger number = more recorded dealer communicationsnot affected vehicles or confirmed faults

These are the issues the manufacturer fixes quietly: service communications sent to dealers without a public recall campaign. They show what the service network has been told even when the issue never became news.

United States · NHTSA manufacturer communications

Caveat worth stating plainly: this is NHTSA data about US-specification cars. British cars sold under the same name often use different gearboxes, engines and equipment, so a bulletin may describe a component that was never fitted here. The file counts dealer communications, not affected vehicles or confirmed failures, and it cannot tell you whether an individual UK car has the issue. A communication can carry more than one subject tag, so topic counts do not have to add up to the total. Source: NHTSA Manufacturer Communications API (US-market vehicles; queried model years 2015-2022). Licence: U.S. Government work / public domain · retrieved 2026-09-25.

Audi S4 owner complaints: what goes wrong

US market, Audi S4, model years 2015–2021 only. A count of owner complaints, not a UK failure rate; NHTSA has no UK denominator.

Lamps & electrical are highest at 15; Suspension is lowest at 1 — the gap is 14.

bigger number = more recorded casescompare like-for-like scope, not sample size alone

Two different populations answering two different questions: the MOT records what an inspector can measure once a year, the complaint file records what annoyed or frightened an owner on the road. A component high in one column and absent from the other is the interesting case — driver-assistance and electronics dominate complaints while almost never appearing as an MOT failure item.

US owners have filed 28 complaints about the equivalent Audi S4 to the National Highway Traffic Safety Administration0. These are owner reports, not verified findings — but they are the only large public record of what drivers themselves notice, and they cover the years between MOT tests.

Caveat worth stating plainly: US-specification cars, self-selected reporters, no denominator — complaint counts scale with how many cars were sold there and how motivated owners are to file. The mechanical gap matters as much as the statistical one: American cars of the same name often carry different gearboxes, engines and equipment — automatics where Britain buys manuals — so a drivetrain complaint filed in Ohio may describe a part that was never fitted here. Read the ranking inside a model, not between models, and treat drivetrain entries with particular caution. Source: NHTSA ODI consumer complaints (US market, public domain) — US-spec vehicles, indicative only.

Audi S4 inspection results in other countries

United Kingdom MOT is well below the reference at 15.2%, against 26.0% nationally.

higher = larger sharecompare shares in percentage points

The verdict is consistent across every regime where the difference is clear, which is the strongest form this comparison takes: independent inspectorates, different rulebooks, same direction of travel.

Worth dwelling on how mundane the top of that list is: tyre pressure, tread depth, headlight aim. The Dutch APK records 0.972 defects per inspection against a much higher national failure rate than Britain's, and the reason is not that Dutch cars are worse — it is that the two regimes draw the line between "note it" and "fail it" in different places. Codes are the RDW's own; the English wording here is our translation of the Dutch original.

Britain is not the only country that inspects every car every year, and the Audi S4 is on the road in all of them. Each national regime writes its own rules, so the pass rates below are not comparable to each other — what does travel across a border is whether a model sits above or below its own country's average.

Rows with fewer than 500 inspections are not published. Sources: RDW open data — Meldingen Keuringsinstantie + Geconstateerde Gebreken + Gekentekende voertuigen (2024), CC0. Not an RDW endorsement.. Adapted; licences and full notice.

Audi S4 MOT: quick answers

Audi S4 MOT Risk Index is well below the reference at 54.2, against 100 for a car with the same age profile.

below 100 is betterabove 100 is worse100 = normal for this model at that age

What is the Audi S4 first-time MOT pass rate?

84.81% of first attempts passed in 2024 (2,436 tests). This is the first-time figure: retests after repair are excluded. Basis: first-time, excluding retests.

Why does this number differ from other sites?

Other sites often report a pass rate that includes retests or counts all attempts. Our 15.19% figure is the first-time initial failure rate, using 2,436 primary tests as the denominator (first-time, excluding retests). The age-adjusted MOT initial-failure ratio 54.2 is shown separately because raw rates compare fleet age as well as cars.

Compare the Audi S4 with other cars

Mercedes-Benz CL is highest at 54.8; Toyota Vitz is lowest at 53.2 — the gap is 1.6 points.

below 100 is betterabove 100 is worse100 = normal for this model at that age

Same brand

All Audi MOT statisticsAudi A7 MOT statsAudi S3 MOT stats

Similar risk

Toyota GR Yaris (index 54.7)Mercedes-Benz CL (index 54.8)Toyota Vitz (index 53.2)

Same size class

how TVR Chimaera compareshow Toyota Vellfire compareshow Aston Martin DB11 compares

By build year

Audi S4 2019Audi S4 2020

By area

Audi S4 MOT failure rate by postcode area

By failure group

Audi S4 body, chassis and structure failuresAudi S4 brakes failuresAudi S4 vehicle identification failuresAudi S4 lamps, reflectors and electrics failuresAudi S4 noise, emissions and leaks failuresAudi S4 road wheels failuresAudi S4 seat belts and airbags failuresAudi S4 steering failuresAudi S4 suspension failuresAudi S4 tyres failuresAudi S4 visibility failures

Inspections abroad

Audi S4 in the Netherlands