Audi A3 2018: reliability & common MOT faults

In 2025, 87 in every 100 first MOTs on a 2018 Audi A3 were passes. Most common reason for a fail: Tyre condition (front).

Summary

A 2018 Audi A3 passed first time about 1 in every 100 more often than the average of the 2017 and 2019 model years.

At a glance

How 25,883 first tests went in 2025.

Passed first time
87 in every 100
Did not pass first time
13 in every 1003,465 failed first-attempt tests
The typical car
7 yearsabout 53,940 miles
First tests counted
25,883

What failed most often

  1. Tyre condition (front)19 in every 100 failed tests
  2. Tyre tread depth (front)12 in every 100 failed tests
  3. Brake pads (rear)10 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2018 Audi A3 vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Suspension

Two faults. The strongest is the shock absorbers (rear): 5.4 times as often as on similar cars.

Figures below are measured across the 3,465 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Shock absorbers (rear)

Failed on 196 first tests5.4 times as often as similar carsStrong evidence

What it means

Slight seepage that leaves a film of fluid on a shock absorber does not fail it. Severe leakage, or damage so that it does not function, is Major. A shock absorber missing or likely to become detached is graded Dangerous, though a missing one is only rejected if shock absorbers were fitted as standard.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 189 first tests, 3.9 times as often as on similar cars.

Coil spring (rear)

Failed on 233 first tests2.0 times as often as similar carsPossible evidence

What it means

A missing bump stop rubber is not a reason to fail a coil spring. When the vehicle is jacked and lowered, a spring that does not correctly locate as the suspension returns to its normal running position is rejected as insecurely attached. A missing spring is Major, and graded Dangerous where directional control is affected.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage. Advisories count notes recorded on failed first tests only.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
87in every 100
Passed on the first test.
Fixed at the station
2in every 100
Failed, then fixed at the test station the same day.
Failed
11in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 86.6% of 25,883 first tests (2025): only cars that passed first time count. Official-style pass 88.7%: cars fixed at the test station also count as a pass. The 2 fixed and the 11 not fixed make the 13 in every 100 that did not pass first time.

By fuel type

First testsTypical mileagePassed first time, as testedPassed first time, same mileage
Petrol21,45551,383 miles8787
Diesel3,97270,250 miles8486
Hybrid45663,010 miles8587

Figures are in every 100 first tests. Cars with more miles usually fail more often, so the same-mileage figure gives every fuel the mileage mix of all the cars in this year.

Same model, other years

Passed first time in every 100, all tested in 2025.

40608010020002005201020152018Older carsNewer cars
406080100200020102018Older cars

Newer cars are younger, so look for a jump rather than the climb.

YearPassed first timeFirst tests
200060 in every 100425
200164 in every 100682
200258 in every 100912
200357 in every 1001,174
200453 in every 1002,446
200556 in every 1005,785
200656 in every 1009,213
200758 in every 10011,651
200859 in every 10015,468
200962 in every 10019,263
201062 in every 10022,121
201164 in every 10019,732
201265 in every 10024,045
201373 in every 10026,090
201477 in every 10037,388
201580 in every 10040,074
201683 in every 10037,389
201785 in every 10032,467
2018 This car87 in every 10025,883
201986 in every 10019,953
202088 in every 10015,234
202188 in every 10019,629
202289 in every 10016,875

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage matters most on a 2018 Audi A3.

Of 2018 Audi A3 vehicles with under 38,000 miles, 91 in every 100 passed their 2025 MOT first time. With 74,000 miles or more, 82 in every 100 did.

Under 38,0005,134 tests
91
38,000–49,0005,279 tests
88
49,000–59,000 Typical car4,907 tests
87
59,000–74,0005,466 tests
84
74,000 and over5,093 tests
82

Petrol or diesel?

Typical mileagePassed first time,
as tested
Passed first time,
same mileage
Petrol51,383 miles8787
Diesel70,250 miles8486

Figures are in every 100 first tests. Petrol cars look better on the raw figures only because diesel cars have done more miles (typically 70,250 against 51,383). At the same mileage there is no clear difference between the two.


What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

Under 38,00049,000–59,00074,000 and over
Tyre condition (front)1.92.72.8
Tyre tread depth (front)0.81.82.5
Brake pads (rear)0.91.61.5
Coil spring (rear)0.60.81.3
Windscreen washers0.40.81.3

Faults per 100 first tests, by the car's mileage at the test.


When a car fails

61in every 100

of failed cars had one item to fix.

13in every 100

of failed cars had three or more items to fix.

6in every 100

of all first tests had a defect the tester marked dangerous (unsafe to drive away).


Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

A 2018 Audi A3 passed first time about 1 in every 100 more often than the average of the 2017 and 2019 model years. In 2025, 86.6% of 25,883 first MOTs on the 2018 Audi A3 passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 88.7%. Among 3,465 failed first-attempt MOT tests (test year 2025), Shock absorbers (rear) appears more often than on similar cars (5.7% of those tests; 196 observed failures; about 5.4× more often than similar cars). There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2018 Audi A3 at the first attempt were Tyre condition (front) (19.2%), Tyre tread depth (front) (12.1%) and Brake pads (rear) (10.2%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Shock absorbers (rear) (5.7% of those tests; 196 observed failures; about 5.4× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Shock absorbers (rear) shows up more often than on similar cars (5.7% of those tests; 196 observed failures; about 5.4× more often than similar cars). That does not prove a design fault. Age, mileage, and how the car was used still matter. Treat it as a pre-purchase checkpoint, not a manufacturer service bulletin.
Common MOT problem areas for the 2018 Audi A3 include Shock absorbers (rear), Coil spring (rear). These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any individual car.
This page highlights MOT failure patterns for the 2018 Audi A3 (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.

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