The Short Answer
The Fiat 500 wins this style-car duel on the number that matters most: first-time MOT pass rate. In the 2024 public UK MOT record, the Fiat 500 posted a
Pass-Rate Split
This is not a normal supermini comparison. The Fiat 500 and Mini are bought with the heart first. People forgive them things they would not forgive in a Hyundai i10, Toyota Yaris or Ford Fiesta. The cabin can be tight. The ride can be firm. Practicality can be treated as someone else’s problem.
That is why the MOT record is useful. It pulls the argument back from image to condition. A cute dashboard and a clever advert do not pass a test. Tyres, brakes, lights, suspension and emissions do.
The Fiat 500 recorded
The Fiat 500 passed 74.56% of tests first time. It failed 20.85%, with 4.09% recorded as PRS. The Mini passed 70.79% first time, failed 22.44%, and had 5.82% PRS.
That split matters. The Mini is worse on the clean-pass number, worse on outright failure, and worse on pass-after-rectification. The Fiat does not just edge it in one awkward corner of the data. It has the cleaner headline record.
On equal condition, equal price and equal history, the Fiat 500 is the safer MOT bet.
Where They Fail
The Fiat 500’s failure list has a clear theme: suspension wear, shock absorbers, tyres, parking brake performance, glass, wipers and small lighting items. Its top recorded failure reasons are:
- Suspension pin, bush or joint excessively worn: 24,005
- Shock absorber bush excessively worn: 16,306
- Shock absorber damaged, not functioning, or showing severe leakage: 10,462
- Tyre tread depth below the required limit: 9,884
- Suspension pin, bush or joint excessively worn: 8,761
That is a very small-car failure profile. The 500 is light, but it is not immune to rough roads, short trips and years of being used as an urban runabout. The suspension figures are the ones to take seriously. Wipers and lamps are cheap. A tired front end or leaking damper changes the way the car drives and the way it eats tyres.
The Mini’s top failure list reads differently. It is more lighting-heavy at the top, but there are also drivetrain, brake pipe and emissions flags close behind. Its leading recorded failure reasons are:
- Rear registration plate lamp or light source missing or inoperative: 24,504
- Windscreen or window damaged or seriously discoloured: 20,873
- Lamp missing, inoperative, or more than half not functioning where multiple light sources are fitted: 19,351
- Headlamp reflector or lens slightly defective: 16,212
- Headlamp aim outside the required limits: 11,475
Those five make the Mini look like a car caught out by lamps, glass and headlamp condition. But stop at five and you miss the nastier shape underneath. The next failures include tyre tread, suspension joint wear, severely deteriorated CV joint boots, lambda readings outside limits, and excessively corroded or damaged brake pipes.
That is the Mini problem in one paragraph. The easy faults are visible. The more expensive ones sit just below them. A used Mini can look charming from five metres away and still be carrying a repair queue underneath.
For buyers, the Fiat inspection path starts at suspension, shocks, tyres and parking brake. For the Mini, start with lamps and screen condition, then go straight under the front corners for CV boots, bushes and brake pipes. Do not let the nicer door thunk distract you.
Cohort Tells
Age bands are where the Fiat 500 result becomes more interesting. The model has a big pre-2018 population, a useful 2018-2020 cohort, and a tiny 2021-on MOT sample. The Mini record here is heavily concentrated in pre-2018 cars, which changes how much we can say about newer examples.
For pre-2018 cars, the Fiat 500 recorded 511,181 tests and a 73.17% pass rate. The Mini recorded 535,343 tests and a 70.79% pass rate. That older cohort is the key used-buyer territory, and the Fiat wins it by 2.38 percentage points.
That is the strongest practical argument in this piece. Older examples are where style cars become risky. They have had more owners, more cheap tyres, more skipped servicing, more kerbed wheels, and more years of small faults being tolerated because the car still looks fun. The Fiat still comes out ahead in the high-volume old-car band.
The 2018-2020 Fiat 500 cohort is much stronger: 63,673 tests and an 85.70% pass rate. That tells you later 500s can be clean MOT cars when age is taken out of the worst part of the equation. They still fail on the same ordinary things: suspension joints, wipers, tyres, brake wear, screen damage and lamps. But the pass rate jumps because fewer cars have reached the tired end of ownership.
The 2021-on Fiat 500 sample is only 212 tests, with an 83.02% pass rate. That is too small to use as the main story. It is useful colour, not the deciding evidence.
The Mini file does not give a meaningful later-cohort split in the same way. Almost the whole recorded sample sits in pre-2018. That means the fairest cohort comparison is older Fiat 500 versus older Mini, and the Fiat still wins.
This does not mean a late Mini is automatically worse than a late 500. It means this specific 2024 model-level record gives us a huge older-Mini signal and a broader Fiat split. For used buyers shopping at the cheaper end, that is enough. The older Fiat 500 has the cleaner MOT pass-rate record.
Mileage Tells
Mileage makes this comparison sharper, because the Mini is carrying far more of it.
The Fiat 500 average mileage at test is 57,439. The Mini average is 91,548. That is a 34,109-mile gap. It is huge. It also explains some of the Mini’s weaker result. A car with more miles has had more time to wear suspension joints, cloud lamps, split rubber boots, corrode pipes, chew tyres and drift into emissions trouble.
But mileage is not a full acquittal. Buyers do not buy an abstract model after normalising the data in a spreadsheet. They buy a car in front of them, with its miles, owners, use pattern and test history. The public record says the Mini population turning up for tests is older and more heavily used, and it fails more often. That is still relevant.
The Fiat’s pre-2018 cohort averages 61,054 miles. The Mini’s pre-2018 cohort averages 91,553 miles. So even in the direct older-car band, the Mini carries roughly 30,500 extra miles at test. Some of the 2.38-point older-car pass-rate gap is mileage. Some is ownership pattern. Some may be the car’s own mechanical ageing. The record cannot perfectly split those causes.
For 2018-2020 Fiat 500s, average mileage is 28,734. That is a much softer life than the old cohort, and the pass rate responds accordingly. It is the cleanest part of the 500 story: if you want the style without the full old-city-car repair pattern, this age band is where the numbers start to behave.
The 2021-on Fiat figure is odd enough to treat carefully. Average mileage is 20,492, but the sample is only 212 tests. Do not build a buying rule around that. Build it around the big samples.
The Mini’s mileage burden is real, but so is the buyer’s risk. You still pay for the wear that has already happened.
A 50,000-mile Mini with an excellent history can beat a 90,000-mile Fiat 500 with repeat suspension advisories. The model result is not a replacement for reading the individual record. It is the starting bias when both cars look similar on paper.
The Numbers We Trust
These figures come from the 2024 public UK MOT record used by this site. The headline measure is first-time pass rate. The test count is the number of recorded tests in the model file. Average mileage is the mileage recorded at test. Failure reasons are the recorded reasons for refusal, grouped by the model-level file.
The clean comparison is:
- Fiat 500: 575,066 tests, 74.56% pass rate, 57,439 average miles
- Mini: 535,385 tests, 70.79% pass rate, 91,548 average miles
- Pass-rate gap: Fiat ahead by 3.77 percentage points
- Fiat pre-2018 cohort: 511,181 tests, 73.17% pass rate, 61,054 average miles
- Mini pre-2018 cohort: 535,343 tests, 70.79% pass rate, 91,553 average miles
- Fiat 2018-2020 cohort: 63,673 tests, 85.70% pass rate, 28,734 average miles
- Fiat 2021-on cohort: 212 tests, 83.02% pass rate, 20,492 average miles
The Fiat failure pattern is more about suspension and shock absorber wear than the car’s soft image suggests. The top five include two suspension joint entries, shock absorber bush wear, shock absorber leakage or damage, and tyre tread depth. That is exactly where a buyer should spend inspection time.
The Mini failure pattern starts with lighting, glass and headlamp condition, but the broader list brings in tyres, suspension joints, CV boots, emissions and brake pipes. That is a wider repair conversation. It does not make the Mini a bad car, but it does make a casual inspection risky.
There are limits. The record does not price repairs. It does not tell you whether a car was serviced properly, whether a previous owner fixed advisories before sale, or whether a garage was stricter than another. It also does not separate one cherished example from a neglected one.
That is why the right move is boring and effective: use the model data to set your suspicion, then read the individual car’s MOT history line by line. Look for repeat advisories, repeat failure families, mileage jumps, corrosion language, tyre neglect, suspension knocks and repairs that seem to move from one corner to another year after year.
For the Fiat 500, repeated suspension wear is the thing to respect. For the Mini, repeated lighting faults are only the surface. You also want proof that CV boots, brake pipes, emissions faults and tyres have not been allowed to pile up.
The Ford Fiesta remains the sensible reference point if you want a less image-led supermini with a huge used market and easier parts shopping.
Verdict
The Fiat 500 wins. It has the higher 2024 first-time MOT pass rate, the better fail-rate profile, and the stronger result in the high-volume pre-2018 cohort. It also carries far lower average mileage at test, which partly explains the win but does not erase it.
The Mini is still the better driver’s car when it is right. It feels more substantial, has a stronger personality from behind the wheel, and many owners will accept higher upkeep for that. But this comparison is not about charm. It is about MOT reality.
On equal condition, buy the Fiat 500. Buy the Mini when the individual car proves it deserves the exception: clean history, sensible mileage, clear lamps, healthy tyres, no repeat CV boot warnings, no brake-pipe corrosion pattern, and no emissions trouble hanging around from one test to the next.