Fault File
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MG 3

All generations and engines together · 21,949 MOT tests in the 2025 data · typical mileage at age 7: 45k

First-time failure at age 7
30.7%
Across 2,652 tests. The average across all tracked models is 19.5%.
Rank at age 7
221 of 239
1 = lowest failure rate among the models tracked.
Typical mileage at age 7
45k miles
Check the mileage view below; low-mileage models can look better by age than they are.

Generation

Split by first-registration year. Cars registered in a changeover year can belong to either generation.

How this model wears

MG 3Class average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 11,081 tests in this band.

A suspension component excessively damaged or corroded
Advisory
17.7%class 1.3%
A suspension pin, bush or joint excessively worn
Advisory
14.9%class 5.9%
Brake pipe damaged or excessively corroded
Advisory
9.9%class 1.9%
A spring or spring component fractured or seriously weakened
Advisory
6.0%class 1.3%
A suspension pin, bush or joint excessively worn
Fail
2.9%class 0.9%
A spring or spring component fractured or seriously weakened
Fail
2.7%class 1.4%
Parking brake efficiency below minimum requirement
Fail
2.7%class 0.3%
A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED
Fail
2.7%class 0.8%
Brake pipe damaged or excessively corroded
Fail
2.2%class 0.2%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
2.0%class 2.0%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
30.9%class 22.9%
A tyre seriously damaged
Advisory
17.0%class 12.7%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
13.7%class 10.1%
A brake lining or pad worn below 1.5mm
Advisory
9.0%class 8.7%
Wiper blade missing or obviously not clearing the windscreen
Fail
4.4%class 1.7%
Tyre tread depth not in accordance with the requirements
Fail
3.1%class 2.2%
Brake disc or drum significantly and obviously worn
Advisory
2.8%class 3.4%
The aim of a headlamp is not within limits laid down in the requirements
Fail
2.6%class 1.5%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Driver's seat latch can let go in a crash (2024-on cars)

Confirmed pattern

Euro NCAP's September 2025 crash test found the right-hand front seat rail on the current MG3 and MG3 Hybrid+ let go under impact, twisting the seat and risking leg and head injuries, something Euro NCAP said it hadn't seen before in its testing. MG fitted a corrected seat rail on the production line from August 2025 and opened a recall that November to retrofit an anchor to earlier cars; by spring 2026 roughly two-thirds of affected cars had been done, with the rest targeted for later in the year. If you're looking at a 2024-on car built before August 2025, get the registration checked for a completed recall before you buy.

Applies to 2024-on cars built before Aug 2025 · sources: Auto Express, Which?, Euro NCAP

Infotainment and electrical niggles

Emerging

Several owners describe the touchscreen or sat-nav locking up or losing its bearings and needing a full factory reset to work again; one owner said their dealer admitted it couldn't be permanently fixed. Other owners report one-off electrical faults, a window that stopped closing partway or a fuel-flap release that stopped springing back. These read as scattered quality-control gremlins rather than one specific part failing, and can turn into a slow fix given MG's patchy dealer back-up.

Reported across a range of ages and mileages · sources: Honest John owner reviews, Auto Express (Driver Power satisfaction survey)

Rust at trim edges and cheap-feeling interior plastics

Disputed

A handful of owners have reported surface rust starting around the windscreen trim and a tow bar mounting point within a few years, and forum posters have long said the interior plastics feel low-rent for the class. It's far from a universal complaint, plenty of owners report no corrosion at all, so treat it as something to check for at a viewing rather than something to expect.

Reported from a few years old · sources: Honest John owner reviews, Honest John forum

Clutch wear on manual cars

Manual cars only

The MG3 is mechanically simple, a five-speed manual with no dual-mass flywheel and no turbo, so there's less on the driveline to fail than on a downsized turbo rival. Even so, at least one owner has reported a clutch needing replacement in normal use; a clutch and slave cylinder job on a car this size typically runs a few hundred pounds. Doesn't apply to CVT automatic versions.

Isolated reports, exact mileage not confirmed · sources: Honest John owner reviews, Honest John forum

Poor owner satisfaction and dealer back-up

Disputed

The mechanicals are simple and generally hold up, but MG has finished bottom of the manufacturer table in Driver Power's customer satisfaction survey for several years running, driven mainly by dealer experience and how slowly niggles get sorted rather than the car breaking down outright. Worth weighing against anything you find at a viewing, on this brand a small fault can take longer to put right than on a mainstream rival.

sources: Auto Express (Driver Power rankings)

Viewing one? Ask this

Built from the two sections above.

Ask to see the recall completion record if the car is a 2024-on model built before August 2025. No record of the seat-latch fix means it needs booking in before you drive it hard.
Run the touchscreen and sat-nav both cold and after it's warmed up, and try a Bluetooth pairing. Freezing or losing its position is the infotainment gremlin some owners couldn't get permanently fixed.
Cycle every window, the fuel flap release and central locking from both the key and the dash. A window that stops mid-travel or a flap that won't spring back points to the electrical niggles owners have flagged.
Check the windscreen trim, wheel arch lips and any tow bar mount for bubbling paint or surface rust. Early corrosion here has come up in a handful of owner reviews, though it isn't universal.
On a manual car, dip the clutch fully on the test drive and note where it bites. A high, sudden or juddery bite point suggests wear worth pricing into your offer.
Pull up the full service and dealer history, not just the MOT record. MG's dealer network scores poorly on customer satisfaction, so unresolved recurring niggles matter more here than on a mainstream brand.
Check the registration on the DVSA recall checker regardless of what the seller says. Confirms whether the seat-latch recall, or any other, is still outstanding on this specific car.

Others in its class

Same segment (Superminis), best MOT record first. Compare before you shortlist.