Model Reports 8 min read Updated 11 Sep 2026 DVSA open data · 2,139 tests analysed

MG 3 2015: reliability & common MOT faults

746 first-attempt MOT failures were recorded on the 2015 MG 3 in 2025. The items recorded most often on them were SRS malfunction indicator lamp and Pins and bushes (front). Figures are among first-attempt failed MOT tests, not among all tests.

2015 3 break the 3's own run — at 65.1% they land 3.6 pp below the midpoint of the 2014 and 2016 cars either side.

First-attempt pass

65.1%

of 2,139 first tests (2025)

First tests

2,139

test year 2025

Failed first attempts

746

failed first-attempt tests

Most common fail

19.4%

SRS malfunction indicator lamp

MOT pass rates

First-attempt and official-style rates among class 4 first tests of the year.

First-attempt pass

65.1%

of 2,139 first tests (2025)

Official-style pass

71.9%

incl. same-day PRS fixes

First tests

2,139

class 4 · first MOT of the year

Typical age 10.0 yrs · median mileage 54,320 mi

vs 2024: -2.0 pp first-attempt

Note:

  • Class 4 cars · first MOT of the year per vehicle · P/PRS/F outcomes (2025 data).
  • PRS (fixed at the station the same day) counts as a fail in the first-attempt rate.
  • Raw outcomes for this cohort — not adjusted for age, mileage, or peer mix.
  • MOT doesn't test engine or gearbox internals.

Common faults

Failure patterns that show up more often on this registration year than on similar cars.

These MOT failure patterns show up more often on this registration year than on similar cars of the same class, age, and mileage.

Shares below are measured across the 739 of 746 failed first attempts (99.1%) that recorded an odometer reading in 2025 — the subset the age-and-mileage comparison can be computed on.

Standout: SRS malfunction indicator lamp — 19.4% of this year's failed first attempts

Recorded on 143 of those tests. It tops the table on elevation — about 23× more often than on similar cars of the same age and mileage. On this year it is also the commonest failure, so it answers both questions at once. The full ranked list is in the table below.

Fault pattern Location Failures vs similar cars Share of fails Confidence
SRS malfunction indicator lamp
Seat belts and supplementary restraint systems > SRS malfunction indicator lamp
 Any 143 ×23 19.4% Strong
Sub-frame (front)
Suspension > Sub-frames > Sub-frame
 Front 31 ×18 4.2% Likely
Rigid brake pipes (front)
Brakes > Rigid brake pipes
 Front 35 ×9.8 4.7% Likely
Pins and bushes (front)
Suspension > Suspension arms > Pins and bushes
 Front 94 ×2.9 12.7% Possible
Shock absorbers (rear)
Suspension > Shock absorbers
 Rear 38 ×2.9 5.1% Possible
Headlamp
Lamps, reflectors and electrical equipment > Headlamps > Headlamp
 Any 47 ×2.4 6.4% Possible
Malfunction indicator lamp
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Malfunction indicator lamp
 Any 45 ×2.1 6.1% Possible

Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and about 2.0× more often than similar cars).

Note: Rates and comparisons are among first-attempt failed tests, not all MOTs. Patterns come from MOT defect codes — not manufacturer service bulletins, recalls, or a diagnosis of any individual car. Failures and advisories are listed separately.

Advisories

Notes recorded at the test that appear more often than on similar cars.

Advisory notes recorded on failed first-attempt tests that appear more often than on similar cars.

Advisory pattern Location Notes vs similar cars Share Confidence
Suspension arm (front)
Suspension > Suspension arms > Suspension arm
 Front 70 ×17 9.5% Elevated
Sub-frame (front)
Suspension > Sub-frames > Sub-frame
 Front 83 ×9.2 11.2% Likely
Rigid brake pipes (front)
Brakes > Rigid brake pipes
 Front 83 ×7.7 11.2% Likely
Rigid brake pipes (rear)
Brakes > Rigid brake pipes
 Rear 43 ×3.3 5.8% Elevated
Coil spring (rear)
Suspension > Springs > Coil springs > Coil spring
 Rear 75 ×3.2 10.1% Elevated
Pins and bushes (front)
Suspension > Suspension arms > Pins and bushes
 Front 121 ×2.5 16.4% Possible
Note: Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.

If you are buying one

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

This year underperforms the 3's own age curve. If the years listed below are in budget, they are the stronger buy on this evidence.

Other 3 years worth knowing about

Newer cars always pass more often, so a plain "best year" list would just rank by age. These are the years that beat or miss the trend their own neighbouring years set — the only age-adjusted signal this data supports.

Year vs the years either side First-attempt pass (rises with newer cars) First tests
2016 3 +3.8 pp better 71.0% 2,888

What to check on a 2015 3

The items that failed 2015 3 most often, as a share of the year's failed first attempts. This is what goes wrong, not what is unusual — the table further up the page covers that.

  • SRS malfunction indicator lamp — recorded on 19.4% of failed first attempts
  • Pins and bushes (front) — recorded on 12.7% of failed first attempts
  • Tyres — Condition (front) — recorded on 8.9% of failed first attempts

Every figure here is a first-attempt MOT rate from DVSA open data for this model line. 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.

2015 3 break the 3's own run — at 65.1% they land 3.6 pp below the midpoint of the 2014 and 2016 cars either side. In 2025, 65.1% of 2,139 first MOTs on the 2015 MG 3 passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 71.9%. Among 746 failed first-attempt MOT tests (test year 2025), SRS malfunction indicator lamp appears more often than on…
Ranked by how often they were actually recorded, the items that failed 2015 MG 3s most often at the first attempt were SRS malfunction indicator lamp (19.4%), Pins and bushes (front) (12.7%) and Tyres — Condition (front) (8.9%) — each as a share of the year's failed first attempts. That is what goes wrong on the car. It is a different question from which patterns are unusual for the class, which the common-faults ta…
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: SRS malfunction indicator lamp (19.4% of those tests; 143 observed failures; about 23× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
SRS malfunction indicator lamp shows up more often than on similar cars (19.4% of those tests; 143 observed failures; about 23× 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 check point, not a manufacturer service bulletin.
Common MOT problem areas for the 2015 MG 3 include SRS malfunction indicator lamp, Sub-frame (front), Rigid brake pipes (front). These patterns show up more often than on similar cars after we filter out sparse noise — not a full list of every possible fault on an individual car.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2015 MG 3 (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.
  • We never invent pass rates, star scores, or ranks when those data marts are missing.

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

Check any vehicle’s MOT history

Full MOT history, mileage records, and reliability insights for any UK vehicle.

Run a free check