The MOT Files

Known faults, from the test record

MG HS common problems

What fails on the MG HS at MOT, which parts are behind it, and how each model year compares. From 32,716 DVSA test records.

Data updated

Quick answer

The MG HS's most common MOT problems are tyres, brake pads and shoes, brake discs, recorded in 33.2%, 24.8% and 19.8% of failed tests respectively. By model year, 2021 cars pass most often (89.9%) and 2022 cars least (87.4%), though most of that gap is age. Every figure here is what testers recorded, not what owners reported.

A “common problems” list is usually a forum thread: whoever had the worst day writes the longest post. This one is built the other way, from every MG HS that took an MOT last year and what the tester wrote down. It cannot see breakdowns, electrical gremlins or a gearbox that hunts, because the test does not check those. What it can see, it sees across 32,716 cars.

By component

What wears out on a HS

Failure items grouped by the part behind them, with the share of failed MG HS tests recording each. A part can carry several DVSA wordings; they are listed beneath. One failed test often lists several items, so shares do not sum to 100%.

  1. 1.Tyres

    33.2% of failed tests

    Tread wears with every mile and sidewalls age and take kerb damage; the legal minimum is 1.6 mm across the central three-quarters.

    • “A tyre seriously damaged” — explained19.2%
    • “Tyre tread depth not in accordance with the requirements” — explained8.7%
    • “A tyre cords visible or damaged” — explained3.5%
    • “A tyre seriously damaged” — explained1.2%

    Across all cars, tyres failures run at a similar rate at every age, because they are replaced on a cycle rather than wearing out with the car. How long tyres last

  2. 2.Brake pads and shoes

    24.8% of failed tests

    Friction material wears with use; the MOT limit is 1.5 mm and a pad that thin is close to metal on metal.

    • “a brake lining or pad worn below 1.5mm” — explained21.7%
    • “Brake lining or pad worn down to wear indicator” — explained3.2%

    Across all cars, brake pads and shoes failures run at a similar rate at every age, because they are replaced on a cycle rather than wearing out with the car. How long brake pads and shoes last

  3. 3.Brake discs

    19.8% of failed tests

    Discs thin with each pad set and pit or corrode when lightly used; failure is for significant wear, fracture or insecurity, advisory for surface condition.

    • “Brake disc or drum significantly and obviously worn” — explained11.6%
    • “Brake disc or drum excessively weakened, insecure or fractured” — explained4.7%
    • “Excessive fluctuation in brake effort through each wheel revolution.” — explained3.5%

    Across all cars, brake discs failures climb 3-fold between three and fifteen years, peaking at 12–14 years. How long brake discs last

  4. 4.Wiper blades and washers

    14.2% of failed tests

    Rubber blades harden and split within a year or two; washer jets block and pumps fail.

    • “Windscreen washers not working or not providing sufficient fluid to clear the windscreen” — explained7.0%
    • “Wiper blade missing or obviously not clearing the windscreen” — explained4.4%
    • “Windscreen washers not working or not providing sufficient fluid to clear the windscreen” — explained2.8%

    Across all cars, wiper blades and washers failures run at a similar rate at every age, because they are replaced on a cycle rather than wearing out with the car. How long wiper blades and washers last

  5. 5.Tyre pressure sensors

    13.5% of failed tests

    Valve-mounted sensors have sealed batteries that expire after roughly seven to ten years; a system fault lamp is a failure on cars first used from 2012.

    • “A tyre pressure monitoring system malfunctioning or obviously inoperative” — explained13.5%

  6. 6.Bulbs and lamps

    7.7% of failed tests

    Filament bulbs simply expire; the cheapest and most avoidable failure on the test, and one of the most recorded.

    • “Headlamp levelling device inoperative” — explained2.1%
    • “A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED” — explained1.9%
    • “An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning” — explained1.5%
    • “An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning” — explained0.9%

    Across all cars, bulbs and lamps failures climb 15-fold between three and fifteen years, peaking at 15+ years. How long bulbs and lamps last

  7. 7.Headlamp aim

    4.6% of failed tests

    Aim drifts with sagging suspension, a knocked lamp or a botched bulb change; adjustment, not a part.

    • “The aim of a headlamp is not within limits laid down in the requirements” — explained3.2%
    • “The aim of a headlamp is not within limits laid down in the requirements” — explained0.8%
    • “The aim of a headlamp is not within limits laid down in the requirements” — explained0.6%

  8. 8.Engine management

    4.6% of failed tests

    The MIL lamp lit is a failure in itself, whatever the stored code; the fault codes section explains what lies behind it.

    • “Engine MIL illuminated indicating a malfunction” — explained4.6%

By registration year

HS problems by year

MOT pass rate for MG HS cars by the year they were first registered, from years with at least 1,000 tests. Every car in a row is the same age, so the rate is raw. Neighbouring years differ by a year of wear — a step of a point or two is age. No single step here is large enough to point at a generation change.

202088%
202190%+2.1
202287%−2.5

Last column: change on the previous year, in points. Years registered within the last three years have not yet been tested and are not shown.

Before it fails

What testers warn HS owners about

Advisories are the same parts a year or two earlier. Share of all MG HS tests carrying an advisory for each.

Go deeper

The rest of the HS file

Common questions

What are the most common problems with a MG HS?
Going by what fails the MOT, tyres (recorded in 33.2% of failed tests), brake pads and shoes (recorded in 24.8% of failed tests), and brake discs (recorded in 19.8% of failed tests). These are the items testers actually record across 32,716 tests, not reports from owners, so they describe what goes wrong at the point where it has to be fixed.
Which MG HS year is the most reliable?
By MOT pass rate, MG HS cars registered in 2021 do best at 89.9% and 2022 cars do worst at 87.4%. Most of that ordering is simply age — newer cars pass more — so read the year table for steps larger than a couple of points between neighbouring years; those mark a change in the cars rather than the calendar.
Is the MG HS reliable?
The MG HS passes 88.3% of MOTs unadjusted; its fleet is too narrow in age or mileage for a fair national comparison. An MOT measures roadworthiness on the day rather than breakdowns or running costs, so this is a reliability measure in the narrow sense: how often the car meets the legal standard, and what stops it.
What should I check when buying a used MG HS?
Start with what fails most: tyres, brake pads and shoes, brake discs. Then read the car's own MOT history for advisories carried year to year without repair — the model tells you what to expect, the history tells you whether this owner dealt with it.

Analysis built from DVSA data of