2025 MOT results
Porsche Boxster common problems
The most common reason a Porsche Boxster fails its MOT is emissions above the limit, on 17.4% of its 5,619 failed tests in 2025. Against other cars of the same age, 3 faults stand out: emissions above the limit at 17.4% of failures against 4.5% expected; corroded brake pipes at 7.5% of failures against 3.9% expected; headlamp aim set too high at 4.6% of failures against 2.8% expected.
- Tests in 2025 32,327 Cars aged three and over
- Failed first time 17.4% 5,619 tests
- Found a dangerous defect 3.4% Unsafe to drive away
- Ended with an advisory 40.4% A problem to watch, not a failure
What fails a Porsche Boxster MOT
Each bar is the share of failed Porsche Boxster tests with that defect. Where we can compare it with cars of the same registration years, the marker shows what an average car of those ages records (12 of the 12 items below).
Most common reasons for failure
A test can fail for more than one defect, so shares add up to more than 100%.
| Defect | Share of failed tests |
|---|---|
| Catalyst emissions: lambda reading after 2nd fast idle outside specified limits Noise, emissions and leaks | 17.4% |
| Coil spring: fractured or broken Suspension | 8.5% |
| Rigid brake pipes: excessively corroded Brakes | 7.5% |
| Position lamp: not working Lamps, reflectors and electrical equipment | 7.2% |
| Wipers: does not clear the windscreen effectively Visibility | 6.8% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 5.5% |
| Headlamp aim: projected beam image is obviously incorrect Lamps, reflectors and electrical equipment | 4.9% |
| Headlamp aim: too high Lamps, reflectors and electrical equipment | 4.6% |
| Parking brake efficiency below requirements Brakes | 4.6% |
| Headlamp: not working on dipped beam Lamps, reflectors and electrical equipment | 4.5% |
| Drive shafts: constant velocity boot split or insecure, no longer prevents the ingress of dirt Body, chassis, structure | 4.0% |
| Stop lamp: not working Lamps, reflectors and electrical equipment | 3.9% |
Source:DVSA,UK Motoring analysis 2025 Updated
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Emissions above the limit
17.4% of failures 4.5% expected 3.9 times as often
The exhaust gases are outside the limits for the car, which can be the catalytic converter, a sensor, or simply a poor state of tune.
A long run before the test helps a catalyst get hot; a persistent failure usually needs a diagnosis.
-
Broken coil spring
8.5% of failures 6.5% expected somewhat more often
A broken suspension spring, which usually snaps in the bottom coil and often fails on both sides within a year.
Look at each corner for a sagging ride height, and listen for a knock over speed bumps.
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Corroded brake pipes
7.5% of failures 3.9% expected 1.9 times as often
Corroded or damaged brake pipework. It is a safety item, and on older cars the rear pipes go first.
Look along the pipes under the sills with a torch; flaking rust rather than surface staining is the problem.
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Sidelight out
7.2% of failures 11.0% expected somewhat less often
A sidelight, also called a position lamp, not working. It marks the width of the car at night.
Walk round the car with the lights on and the hazards going; these are the cheapest failures to avoid.
-
Wiper blades that do not clear the screen
6.8% of failures 7.3% expected about as expected
Wiper blades that leave the windscreen smeared or streaked across the area the driver looks through.
Look for split or hardened rubber, and lift each blade to see whether it still sits flat.
-
Tyre worn below the legal limit
5.5% of failures 5.9% expected about as expected
A tyre worn past the 1.6mm legal minimum across the middle three quarters of the tread.
A 20p coin in the main grooves: if the outer band of the coin is visible, the tyre is close to the limit.
Which parts of the car fail
Lamps, reflectors and electrical equipment is the area that most often fails a Porsche Boxster, on 36.9% of failed tests. The widest gap against cars of the same registration years is noise, emissions and leaks, on 25.3% against 16.9% expected.
Failure categories
DVSA's own sections of the test. The marker is what cars of the same registration years record.
| Defect category | Share of failed tests |
|---|---|
| Lamps, reflectors and electrical equipment | 36.9% |
| Noise, emissions and leaks | 25.3% |
| Suspension | 22.4% |
| Brakes | 21.6% |
| Tyres | 15.8% |
| Visibility | 13.6% |
| Body, chassis, structure | 10.0% |
| Steering | 4.6% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
40.4% of Porsche Boxster tests ended with at least one advisory: a fault the tester found that did not fail the test. On Porsche Boxsters, these are the items to ask about on a car you are viewing, because they are what the last tester expected to go next.
Most common advisories
Share of all tests, passes included.
| Advisory | Share of tests |
|---|---|
| Rigid brake pipes: corroded, covered in grease or other material Brakes | 12.1% |
| Tread depth: worn close to legal limit or worn on edge Tyres | 9.8% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 9.7% |
| Tyres: slightly damaged or cracking or perishing Tyres | 7.2% |
| Engine oil leak, but not excessive Noise, emissions and leaks | 5.2% |
| Play in steering rack inner joint(s) Non-component advisories | 2.2% |
| Exhaust system: minor leak of exhaust gases Body, chassis, structure | 2.1% |
| Suspension arms: ball joint has slight play Suspension | 2.0% |
| Suspension arms: pin or bush worn but not resulting in excessive movement Suspension | 1.9% |
| Shock absorbers: light misting of oil Suspension | 1.5% |
| Nail in tyre Non-component advisories | 1.5% |
| Brake pads: wearing thin Brakes | 1.4% |
Source:DVSA,UK Motoring analysis 2025 Updated
Porsche Boxster problems: common questions
What is the most common problem with a Porsche Boxster?
Of the faults that fail an MOT, “Catalyst emissions: lambda reading after 2nd fast idle outside specified limits” is the most common: it appears on 17.4% of failed Porsche Boxster tests. Across categories, lamps, reflectors and electrical equipment is the area that most often fails one, on 36.9% of failed tests.
How often does a Porsche Boxster fail its MOT?
17.4% of Porsche Boxster tests in 2025 were not passed first time, from 32,327 tests of cars aged three and over. Allowing for the age and mileage of the cars tested, that gives it a UK Motoring Reliability Score of 75 out of 100, where 50 is as expected.
Does anything fail more often on a Porsche Boxster than on other cars?
Yes. “Catalyst emissions: lambda reading after 2nd fast idle outside specified limits” appears on 17.4% of its failures against 4.5% for cars of the same age, and “Rigid brake pipes: excessively corroded” appears on 7.5% of its failures against 3.9% for cars of the same age. Where an item is missing from the national figures for a year, we use the smallest share those figures show, so the comparison never overstates the difference.
Are these the same as breakdowns or known faults?
No. These are the items a tester recorded at the MOT, which covers condition and safety: lamps, brakes, tyres, suspension, corrosion and emissions. A gearbox that is unpleasant, an infotainment screen that has died, or a car that will not start on a cold morning are not part of the test, so they are not in these figures.
Where do the figures come from?
Every normal MOT test of a Porsche Boxster aged three and over in Great Britain in 2025, from DVSA's anonymised MOT results. Retests are excluded, and the same fault on more than one wheel counts once.
Data stories to read next
Data sources and methodology
| Figures | Source | Period | Records | Updated |
|---|---|---|---|---|
| MOT defects and advisories | Anonymised MOT tests and results Driver and Vehicle Standards Agency Derived statistics UK Motoring | 2025 | 32,327 MOT tests | 19 September 2026 |
- Shares for defects are of failed tests; shares for advisories are of all tests. A test can carry several defects, so shares add to more than 100%.
- The expected share is what an average car of the same registration years records, weighted by where this model’s failures fall. Where an item is outside the national figures for a year, the smallest share those figures show is used in its place, which is an upper bound, so the comparison never overstates a model’s problems. No expectation is published where less than 80% of the model’s failures can be compared.
- Great Britain only: DVSA does not run MOT testing in Northern Ireland. Cars under three years old are not tested.
- The descriptions of what each part does are general and the same on every model. Every figure comes from the MOT data.
Contains public sector information licensed under the Open Government Licence v3.0.