Model Reports 4 min read Updated 18 Oct 2026

MG TF 2005: reliability & common MOT faults

In 2025, 72 in every 100 first MOTs on a 2005 MG TF were passes. Most common reason for a fail: Petrol emissions (with catalyst).

Summary

The 2005 MG TF follows the pattern of the model years either side.

At a glance

How 1,094 first tests went in 2025.

Passed first time
72 in every 100
Did not pass first time
28 in every 100308 failed first-attempt tests
The typical car
20 yearsabout 50,924 miles
First tests counted
1,094

What failed most often

  1. Petrol emissions (with catalyst)16 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 2005 MG TF 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 suspension arm (front): 18 times as often as on similar cars.

Figures below are measured across the 307 of 308 failed first attempts (99.7%) that recorded an odometer reading in 2025. Mileage is needed to compare like with like.

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.

Suspension arm (front)

Failed on 21 first tests18 times as often as similar carsPossible evidence

What it means

A missing bump stop rubber is not a reason to fail a suspension arm. A component that is fractured, missing or likely to fail is graded Dangerous, and one excessively damaged or corroded is Major. On some vehicles, some highly stressed parts are thin pressed steel, and many of those have hollow box sections or up-facing areas that can collect road dirt and salt, so they get special attention.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 23 first tests, 2.6 times as often as on similar cars.

Suspension arm ball joint (front)

Failed on 23 first tests2.2 times as often as similar carsPossible evidence

What it means

A suspension arm ball joint is failed under the general suspension pin, bush or joint wording. Excessively worn is Major, and likely to become detached is graded Dangerous.

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

Lamps and electrical

One fault: horn, 6.7 times as often as on similar cars.

Horn

Failed on 29 first tests6.7 times as often as similar carsPossible evidence

What it means

A horn that does not work, or is likely to be confused with an emergency vehicle siren, is graded Major. Gongs, bells, sirens and anything with more than one tone, which includes a horn that alternates between its notes, are not allowed, except a gong, bell or siren on vehicles first used before a set date. Sound defects are Minor for named cases such as a bell or harsh sound, and Major under a general row.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Noise, emissions and leaks

One fault: petrol emissions (with catalyst), 3.7 times as often as on similar cars.

Petrol emissions (with catalyst)

Failed on 50 first tests3.7 times as often as similar carsLikely evidence

What it means

Emissions levels over the manufacturer's specified limits are Major, as are levels over default limits, which apply when no exact match is found for the vehicle. Dense blue or clearly visible black smoke at idle, held for a set period, is Major, except for certain older vehicles and two stroke engines where smoke is unavoidable. An induction or exhaust leak that could affect emissions levels is Major too.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Brakes

One fault: handbrake efficiency below minimum (roller test), 2.6 times as often as on similar cars.

Handbrake efficiency below minimum (roller test)

Failed on 46 first tests2.6 times as often as similar carsPossible evidence

What it means

A parking brake with efficiency below the minimum requirement is Major, and graded Dangerous where efficiency is less than half of the required value. On a roller brake tester, the requirement counts as met if more than half of the wheels of a brake system lock. The check applies only to vehicles whose parking brake was not already tested as the secondary brake.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Steering

One fault: track rod end (front), 2.1 times as often as on similar cars.

Track rod end (front)

Failed on 20 first tests2.1 times as often as similar carsPossible evidence

What it means

A steering ball joint with excessive wear or free play is Major, and one worn to the extent there is a serious risk of detachment is graded Dangerous. A dust cover that is damaged but still keeps dirt out is Minor, and one missing or no longer keeping dirt out is Major. Testers must tell wear from a joint's built-in clearance or spring loading.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 24 first tests, 6.5 times as often as on similar cars.

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

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail. Advisories for the faults above are shown with those faults.

Suspension sub-frame (rear)

Noted on 49 first tests3.7 times as often as similar carsElevated evidence

Suspension sub-frame (front)

Noted on 32 first tests3.1 times as often as similar carsElevated evidence

Brake discs (rear)

Noted on 40 first tests2.4 times as often as similar carsWear pattern

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

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

Passed first time
72in every 100
Passed on the first test.
Fixed at the station
3in every 100
Failed, then fixed at the test station the same day.
Failed
25in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 71.8% of 1,094 first tests (2025): only cars that passed first time count. Official-style pass 75.0%: cars fixed at the test station also count as a pass. The 3 fixed and the 25 not fixed make the 28 in every 100 that did not pass first time.

Same model, other years

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

YearPassed first timeFirst tests
200269 in every 1001,553
200366 in every 1002,342
200469 in every 1002,257
2005 This car72 in every 1001,094

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 71 in every 100 passed first time.

FAQs

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

The 2005 MG TF follows the pattern of the model years either side. Its main cause of failure was Petrol emissions (with catalyst), about 16 in every 100 failed tests. In 2025, 71.8% of 1,094 first MOTs on the 2005 MG TF passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 75.0%. Among 308 failed first-attempt MOT tests (test year 2025), Suspension arm (front) appears more often than on similar cars (6.8% of those tests; 21 observed failures; about 18× 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 2005 MG TF at the first attempt were Petrol emissions (with catalyst) (16.3%), 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: Suspension arm (front) (6.8% of those tests; 21 observed failures; about 18× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Suspension arm (front) shows up more often than on similar cars (6.8% of those tests; 21 observed failures; about 18× 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 2005 MG TF include Suspension arm (front), Horn, Petrol emissions (with catalyst). These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any 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 2005 MG TF (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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