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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

Reliability verdict
EBy age
DBy miles

Graded against its peers

One of the worst superminis to buy at this age, and worse than most per mile driven. Watch suspension and brakes. A risky used buy. Check the MOT history for repeating suspension advisories before you go.

First-time failure at age 7
30.7%
Across 2,652 tests. The average for superminis is 23.3%.
First-time failure at 50-60k miles
34.0%
Across 2,510 tests. The average for superminis is 28.9%.
Rank in its class
19 of 27
1 = lowest failure rate among the 27 superminis we can rank.
Typical mileage at age 7
45k miles
How far the average car has gone by seven years old. 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.

What owners report

Reported

Owner folklore from forums and the motoring press, with how well each report stands up. 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

DisputedManual 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)

What to check on this car

Ranked from this model’s own MOT record, then from what owners report.

Saveable checklist

From this model’s MOT record

The physical checks its own defect data says are worth your time, most telling first.

Bushes and ball jointsRuns high on this model Drive slowly over broken tarmac with the windows down and listen for clonks from either end. Back at the car, have someone rock the steering wheel while you rest a hand on each front wheel; play you can feel through the tyre is a worn joint.Recorded on 14.9% of tests at age 6-9 · class average 5.9%
Brake pipes underneathRuns high on this model Follow the metal brake lines with a torch where they run along the sills and over the rear axle. White crust or flaking metal means they are corroding, and the online MOT history usually shows the same advisory creeping up for years before the fail.Recorded on 9.9% of tests at age 6-9 · class average 1.9%
Underneath, with a torchRuns high on this model Get down and look at the sills, the subframes and the rear suspension mounting points. Flaking scale and bubbling matter; light surface rust does not. On older cars this is the one check that finds the fault that scraps them.Recorded on 9.4% of tests at age 6-9 · class average 0.7%
Coil springsRuns high on this model Look through the wheel spokes at the bottom coil of each spring; when springs snap it is usually there, and the break is visible. Step back and check the car sits level too. A dropped corner is often a broken spring.Recorded on 6.0% of tests at age 6-9 · class average 1.3%
Handbrake holdRuns high on this model Stop on a hill and put the handbrake on. It should hold the car firmly within a few clicks, or straight away on the button if it is electronic. Roll-back means adjustment at best, new cables or a caliper motor at worst.Recorded on 2.7% of tests at age 6-9 · class average 0.3%
Lights and horn walkroundRuns high on this model With a helper, run every light: dipped, main beam, indicators, brake lights including the high-level one, reverse, fog, and the horn. On newer cars a dead LED section can mean replacing the whole lamp unit rather than a bulb.Recorded on 2.7% of tests at age 6-9 · class average 0.8%
Warning lights on ignitionRuns high on this model Turn the ignition on without starting the engine and watch the dash. Every warning light should appear, then go out once it is running. Be more suspicious of a light that never comes on at all than of one that stays on; warning bulbs have been known to vanish before a sale.Recorded on 2.0% of tests at age 6-9 · class average 0.2%

Worth doing on any used car

These judge the seller’s upkeep rather than the model, and they are where the haggling money is.

Tyres, all four Check the tread across the full width of each tyre, inner edge included, and look for cracking and mismatched brands. A set of decent tyres is £500 or more on most cars, which makes this the easiest money to take off a price. If the pressure warning light is on, budget for sensors too.Recorded on 27.8% of tests at age 6-9 · class average 20.1%
Pads and discs Look through the wheel spokes at the brake disc. A pronounced lip on its outer edge, or a rusty and scored face, means discs and pads are due all round, a few hundred pounds on most cars. A haggling point rather than a reason to walk away.Recorded on 13.7% of tests at age 6-9 · class average 10.1%
Windscreen and wipersRuns high on this model Scan the glass in daylight for chips, especially in the driver's line of sight where even a small one can fail the MOT. Run the washers and check the wipers clear without smearing.Recorded on 4.4% of tests at age 6-9 · class average 1.7%

Because of what owners report

Drawn from the reports above rather than the MOT data. These are the model-specific ones.

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.

Open the saveable checklist, tick it off at the car

The MOT data

Measured

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

How this model wears

MG 3Class average, all tracked models

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
2.3%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 2.3%
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%

Others in its class

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

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