Data study · failure rates at matched age
MOT failure rates by car
Published MOT failure rates by car compare vehicles of different ages, which mostly measures how old each model’s fleet is. Compare them at the same age and the order changes — and the repair bill turns out to matter far less than how often the test is failed at all.
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Compared at exactly ten years old in DVSA MOT data analysed by PriceMyRepair, a Renault Laguna fails its MOT 37.8% of the time and an Audi Q5 17.7% — the same age, the same test, twice the risk. Yet the repair behind each failure costs £124 and £108. Across 144 models, failure frequency varies 2.14× while the cost per fault varies only 1.41×.
2.14×
how much failure rates vary between models of identical age — 37.8% at worst against 17.7% at best
1.41×
how much the repair cost behind each failure varies across the same 144 models
5%
how much more the worst-failing models cost per fault than the best — the two things are almost unrelated
Why every other ranking is measuring the wrong thing
Rank models by failure rate without controlling for age and a very consistent list appears: Laguna, 206, Vectra, Xsara at the top; Up, Tiguan, A1 at the bottom. It looks like a verdict on build quality. It is mostly a verdict on when each model was sold.
Failure risk rises steeply with age, so a model’s rank follows its fleet. A car that left showrooms two decades ago has an average age near twenty; one launched recently has an average age near six. Put both in the same table and the older nameplate loses before any part is inspected. The comparison never touched the cars — it compared their birthdays.
The fix is to hold age fixed and compare only what is left. Every figure on this page is drawn from cars at exactly ten years old, an age where the fleet is large enough for reliable numbers across a wide range of models and where wear faults have had time to appear. Nothing here mixes ages, and nothing is averaged across an age band.
The order changes once you do. Some names stay put and some move a long way. What survives the correction is a real difference between cars — and it is smaller than the uncorrected version suggests, because part of that apparent gap was never about the car.
The models that fail most at ten years old
The Renault Laguna, Renault Megane and Renault Clio have the highest MOT failure rates at ten years old — 37.8%, 36.7% and 36.7% of tests failed — according to DVSA data analysed by PriceMyRepair. The table shows the share of tests failed by each model at exactly ten years of age, with the average repair cost behind each recorded fault alongside.
| Model | Fails at ten years | Cost per fault | Tests |
|---|---|---|---|
| Renault Laguna | 37.8% | £124 | 292,161 |
| Renault Megane | 36.7% | £120 | 679,410 |
| Renault Clio | 36.7% | £115 | 1,272,715 |
| Vauxhall Vectra | 36.6% | £130 | 769,798 |
| Ford Ka | 36.4% | £127 | 813,283 |
| Renault Kangoo | 36.4% | £111 | 153,262 |
| Peugeot 206 | 36.2% | £113 | 838,895 |
| Peugeot 307 | 36.1% | £108 | 402,587 |
| Fiat Punto | 35.5% | £116 | 658,487 |
| Renault Scenic | 35.5% | £115 | 205,052 |
| Ford Transit | 35.5% | £111 | 1,211,885 |
| Vauxhall Combo | 35.2% | £118 | 244,352 |
| Vauxhall Vivaro | 34.9% | £133 | 258,039 |
| Renault Trafic | 34.9% | £131 | 144,890 |
Vans appear here alongside cars because the light commercial fleet takes the same class of test and is worked far harder, which shows up as brake, suspension and body faults rather than anything unique to the vehicle. Every row rests on at least 50,000 tests at this age.
The models that fail least at the same age
The Audi Q5, Mini Cooper and Audi A5 have the lowest MOT failure rates at ten years old — 17.7%, 18.5% and 20.4% of tests failed — in PriceMyRepair’s analysis of the same DVSA data. The other end of the same table, on the same terms.
| Model | Fails at ten years | Cost per fault | Tests |
|---|---|---|---|
| Audi Q5 | 17.7% | £108 | 52,582 |
| Mini Cooper | 18.5% | £96 | 76,417 |
| Audi A5 | 20.4% | £99 | 97,236 |
| Audi Q3 | 20.7% | £122 | 58,776 |
| Mercedes-Benz SLK | 20.9% | £129 | 90,757 |
| Honda Jazz | 21.0% | £106 | 379,029 |
| Skoda Yeti | 21.0% | £128 | 64,831 |
| Toyota Prius | 21.5% | £94 | 114,856 |
| Jaguar XF | 21.7% | £108 | 98,881 |
| Volvo XC60 | 21.8% | £121 | 55,401 |
| Toyota Auris | 22.2% | £110 | 149,833 |
| Volkswagen Tiguan | 22.6% | £132 | 106,305 |
| BMW 1 Series 116 | 22.6% | £96 | 121,811 |
| Audi A1 | 22.8% | £136 | 136,532 |
Sports cars and large SUVs are over-represented here for a reason worth naming: these are often second cars, driven fewer miles a year, and mileage does more damage than time. The age curves show the same effect from the other direction. Two Toyota RAV4 spellings exist in the source record and both were excluded rather than guess which cars sit under each.
The column nobody else publishes — and what it says
Across 144 models at ten years old, the average repair cost behind an MOT fault runs from £94 (Toyota Prius) to £133 (Vauxhall Vivaro) — a 1.41× spread, according to PriceMyRepair’s analysis. Every ranking of this kind stops at the percentage; the obvious next question is what the failure costs, and the answer is more interesting than a bigger number for worse cars.
The cost per fault barely moves. Across 144 models it runs from £94 to £133 — a spread of 1.41×, against 2.14× for the failure rate itself. Whatever a car is, when it fails an MOT it fails on brakes, suspension, tyres, lamps and exhausts, in broadly similar proportions, at broadly similar prices.
And the two are almost unrelated. The fourteen worst-failing models average £119 per fault; the fourteen best average £113. Five per cent, set against a doubling of how often the fault appears at all. A Toyota Prius has one of the lowest costs per fault on this page and a mid-table failure rate; an Audi A1 has one of the highest costs and one of the lowest failure rates.
In PriceMyRepair’s data, how often a car fails its MOT varies twice as much between models as what each failure costs to fix. If your annual repair bill is roughly how often something fails multiplied by what it costs, and the cost term barely varies while the frequency term doubles, then choosing a car on what its parts cost is optimising the smaller half of the equation. A model that fails half as often is worth far more than one whose components are 5% cheaper.
It also undercuts the premise of the badge. Cars in the best-performing table are largely premium and cars in the worst are largely mainstream, but the mechanism is not build quality alone — it is how hard each is driven and what it is used for. Second cars, sports cars and large SUVs cover fewer miles a year, and mileage is what wears the parts the MOT inspects.
How to use this if you are buying
A model-level failure rate is a starting point about a population, not a prediction about the specific car in front of you.
Use it to set expectations
A model near the top of the first table will need work more often than one near the top of the second. That is a budgeting fact, not a reason to walk away.
Budget for frequency, not for parts pricesThen ignore it and read the history
An individual car’s own MOT record beats any model average. Repeated advisories on the same corner tell you more than a national percentage ever will.
The certificate names next year’s billAsk what the miles were
Much of the gap between these two tables is use, not engineering. A high-mileage example of a low-failure model can be worse than a gentle example of a high-failure one.
Mileage wears the parts the test checksA failed MOT is not the same as an unreliable car. The test inspects brakes, tyres, suspension, lights, structure and emissions — it says nothing about gearboxes, clutches, turbos or electronics, which is where a large share of expensive breakdowns actually live. See what the MOT actually checks for the gap between the two ideas.
Enter your reg — we’ll read its full MOT history, show every advisory a tester has recorded and price each repair for your model rather than the national average.
How these figures were produced
Method
Source. The DVSA MOT testing bulk dataset, published under the Open Government Licence v3.0 and analysed by PriceMyRepair. 829,654,015 tests and 697,809,455 recorded defects, covering Great Britain. Northern Ireland runs a separate system under the DVA and is not in this data.
Failure rate. Tests failed divided by tests taken, for vehicles of that make and model at exactly ten years of age. Both terms are counts of tests, so the figure is unaffected by how defects are recorded. Models are included only where at least 50,000 tests exist at this age; 144 models qualify.
Why ten years. Comparing models of different ages measures fleet age rather than the vehicles. Ten years is old enough for wear faults to have appeared and recent enough that a wide range of models still has a large fleet on the road. Holding age fixed is the single most important choice on this page.
Cost per fault. Each recorded failure item is mapped to a repair category, and each category to our published independent-garage price range for that repair; the figure is the average of the range midpoints across that model’s failure items. Repair prices are our own estimates and are not part of the DVSA dataset — the two sources are combined here and nowhere in the official record.
Why cost is expressed per fault and not per test. The dataset records defects only under the current MOT manual scheme, which excludes 1.18 billion earlier defect records while the test counts cover the full period. Any cost expressed per test would therefore be understated, and understated by more for models with a longer history — which would reintroduce exactly the age bias this page exists to remove. Dividing by faults keeps the numerator and denominator inside the same records.
Known limitations. Two spellings of one Toyota model exist in the source and both were excluded rather than merged on a guess. Failure rates are not adjusted for mileage, region or how a vehicle is used, and the tables show that use explains a meaningful part of the spread. A model that has been sold across several generations is treated as one nameplate. Repair categories are matched from the defect text, so faults with unusual wording are counted in the failure rate but carry no price; average coverage is 83% of failure items and no model is published below the threshold. Repair ranges are estimates and final quotes come from garages.
Contains public sector information licensed under the Open Government Licence v3.0.
MOT failure rates — FAQ
Which car has the highest MOT failure rate?
Compared at ten years old, the Renault Laguna at 37.8% of tests failed. Comparisons that do not control for age produce a different and less meaningful answer, because older nameplates have older fleets and failure risk climbs steeply with age. Every figure here is drawn from cars of exactly the same age.
Which car has the lowest MOT failure rate?
The Audi Q5 at 17.7%, again at ten years old, followed by the Mini Cooper at 18.5% and the Audi A5 at 20.4%. Part of that advantage is genuine and part is use: cars of this kind cover fewer miles a year, and mileage wears the components the test inspects.
Why compare cars at the same age rather than overall?
Because an overall ranking mostly measures how old each model’s fleet is. Models discontinued long ago have average ages near twenty and models launched recently near six, so the older nameplate loses before any component is inspected. Holding age fixed removes that and leaves a real difference between vehicles.
Does a high failure rate mean a car is unreliable?
Not in the usual sense. The MOT inspects brakes, tyres, suspension, lights, structure and emissions, and says nothing about gearboxes, clutches, turbos or electronics — where a large share of expensive breakdowns sit. A car can fail regularly on cheap wear items and never leave anyone stranded.
Do cars that fail more often also cost more to repair?
Barely. The worst-failing models average £119 per fault and the best average £113 — five per cent, against a doubling of how often a fault appears. Failure frequency varies 2.14× across the models here while cost per fault varies 1.41×, and the two are only weakly related.
Why do vans appear in a car failure ranking?
Light commercial vehicles take the same class of test as cars and are worked far harder, which shows up as brake, suspension and body faults rather than anything peculiar to the vehicle. Leaving them out would hide a real and useful pattern about how use drives failure.
What do cars actually fail their MOT on?
Overwhelmingly the same handful of things regardless of badge: suspension, tyres, brakes, lamps and exhausts. That sameness is why the cost per fault varies so little between models. What differs is how often those items reach the failure threshold, not what they are.
Does mileage matter more than the model?
The tables suggest it matters a great deal. Sports cars and large second cars cluster at the low-failure end, and the most obvious thing they share is covering fewer miles a year. We have not yet published a mileage-controlled comparison, so this page does not claim one.
Can I use this to predict whether my car will fail?
Only loosely. A model average describes a population of hundreds of thousands of vehicles, not yours. A specific car’s own MOT history is far more informative — repeated advisories on the same corner are a scheduled repair announcing itself, and our advisory decoder reads and prices them.
How much does an MOT cost, and what if it fails?
The test itself is capped at £54.85 and most garages charge £35–£55. A failure adds the repair, and the retest is usually free within ten working days if the car stays at the garage. What that repair costs depends on the fault rather than the model — see our full price guides.
Related studies and guides
This page is the model axis. The same dataset cut two other ways.