Mazda MX-5 2018: reliability & common MOT faults

In 2025, 89 in every 100 first MOTs on a 2018 Mazda MX-5 were passes. Most common reason for a fail: Brake pads (front).

Summary

The 2018 Mazda MX-5 follows the pattern of the model years either side.

At a glance

How 4,111 first tests went in 2025.

Passed first time
89 in every 100
Did not pass first time
11 in every 100450 failed first-attempt tests
The typical car
7 yearsabout 27,897 miles
First tests counted
4,111

What failed most often

  1. Brake pads (front)14 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2018 Mazda MX-5 vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. A wear pattern follows age and use more than the way the car was built. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Brakes

Two wear patterns. The strongest is the brake discs (rear): 4.9 times as often as on similar cars.

Figures below are measured across the 450 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Brake discs (rear)

Failed on 25 first tests4.9 times as often as similar carsWear pattern

What it means

A brake disc or drum must be significantly worn before it is rejected, and being worn below the manufacturer's recommended limits is not a reason in itself. Significantly and obviously worn is Major, as is contamination with oil or grease. A disc or drum that is fractured, insecure, seriously weakened or missing is graded Dangerous.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 92 first tests, 3.3 times as often as on similar cars.

Brake pads (front)

Failed on 62 first tests2.5 times as often as similar carsWear pattern

What it means

A pad worn down to its wear indicator, or contaminated with oil or grease, is Major. A pad worn below the set thickness limit, missing or incorrectly mounted is Dangerous. The manual treats an illuminated brake wear indicator as no reason for failure, although DVSA also lists an illuminated indicator as a Major row.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage. Advisories count notes recorded on failed first tests only.

Tyres

One wear pattern: tyre tread depth (rear), 2.8 times as often as on similar cars.

Tyre tread depth (rear)

Failed on 26 first tests2.8 times as often as similar carsWear pattern

What it means

Only primary grooves count when tread depth is assessed: those holding the wear indicators, or cut as deep as those when new. Shallower secondary grooves are ignored. Tread depth below the minimum for the vehicle is Dangerous, and so is a pattern not visible over the whole tread, but that second row applies only to vehicles that need the lower minimum.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Lamps and electrical

One wear pattern: headlight aim, 2.0 times as often as on similar cars.

Headlight aim

Failed on 46 first tests2.0 times as often as similar carsWear pattern

What it means

Beam aim too high, too low or off to either side is Major. Where a driver's beam aim control is fitted, the aim is tested without altering the setting, and rechecked at the highest setting only if it would fail for being too low. Masks or converter kits on right hand dip headlamps are acceptable.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail. Advisories for the faults above are shown with those faults.

Suspension arm pins and bushes (rear)

Noted on 21 first tests17 times as often as similar carsElevated evidence

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
89in every 100
Passed on the first test.
Fixed at the station
4in every 100
Failed, then fixed at the test station the same day.
Failed
7in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 89.1% of 4,111 first tests (2025): only cars that passed first time count. Official-style pass 92.5%: cars fixed at the test station also count as a pass. The 4 fixed and the 7 not fixed make the 11 in every 100 that did not pass first time.

Same model, other years

Passed first time in every 100, all tested in 2025.

4060801001990199520002005201020152018Older carsNewer cars
4060801001990200020102018Older cars

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 90 in every 100 passed first time.

YearPassed first timeFirst tests
199068 in every 100706
199164 in every 100756
199262 in every 100556
199367 in every 100523
199467 in every 100465
199568 in every 100721
199666 in every 1001,076
199767 in every 1001,589
199868 in every 1002,159
199965 in every 1002,255
200062 in every 1002,217
200167 in every 1001,631
200265 in every 1002,616
200362 in every 1003,309
200464 in every 1002,580
200566 in every 1002,775
200667 in every 1005,552
200769 in every 1006,988
200868 in every 1004,996
200971 in every 1003,926
201073 in every 1004,428
201176 in every 1003,235
201279 in every 1002,987
201379 in every 1002,983
201481 in every 1002,754
201585 in every 1002,891
201686 in every 1003,934
201789 in every 1004,422
2018 This car89 in every 1004,111
201992 in every 1003,880
202092 in every 1001,038
202195 in every 1001,426
202294 in every 1001,300

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage matters most on a 2018 Mazda MX-5.

Of 2018 Mazda MX-5 vehicles with under 17,000 miles, 94 in every 100 passed their 2025 MOT first time. With 42,000 miles or more, 84 in every 100 did.

Under 17,000860 tests
94
17,000–24,000781 tests
92
24,000–32,000 Typical car831 tests
89
32,000–42,000782 tests
86
42,000 and over857 tests
84

What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

Under 17,00024,000–32,00042,000 and over
Brake pads (front)0.31.71.8

Faults per 100 first tests, by the car's mileage at the test.


When a car fails

57in every 100

of failed cars had one item to fix.

18in every 100

of failed cars had three or more items to fix.

4in every 100

of all first tests had a defect the tester marked dangerous (unsafe to drive away).


Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

The 2018 Mazda MX-5 follows the pattern of the model years either side. Its main cause of failure was Brake pads (front), about 14 in every 100 failed tests. In 2025, 89.1% of 4,111 first MOTs on the 2018 Mazda MX-5 passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 92.5%. Among 450 failed first-attempt MOT tests (test year 2025), we highlight MOT failure patterns that show up more often than on cars of a similar age and mileage when the sample is large enough to trust. There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2018 Mazda MX-5 at the first attempt were Brake pads (front) (13.8%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2018 Mazda MX-5 (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.

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