Mazda Rx 8 MOT Failures
An analysis of 76,224 real DVSA MOT tests on the Mazda Rx 8 — what fails, how often, and how that compares to every other car on UK roads. Generations covered: SE (2003–2008), SE3P (2008–2012).
Where the Mazda Rx 8 fails its MOT
The single biggest MOT failure point on the Mazda Rx 8 is emissions failure — this model is 78 times more likely to fail on this item than the average car on UK roads. That makes it a major concern for anyone buying or owning this model. Across 76,224 MOT tests, 1.38% of all Mazda Rx 8 tests recorded this as a failure.
Exhaust and emissions failures often point to catalytic converter degradation, lambda sensor faults, or — in diesel models — DPF problems. These can be expensive to fix and will cause an immediate MOT failure.
Other notable weak points include anti-roll bar links worn (56x the fleet average), suspension ball joints worn (125x the fleet average), headlight fault (19x the fleet average), and power steering fault (124x the fleet average). These ratios compare the Mazda Rx 8's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 5 categories: Exhaust & Emissions, Suspension, Lights & Electrics, Steering, Bodywork. If you're inspecting a Mazda Rx 8 before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Mazda Rx 8's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Mazda Rx 8 specifically, the DVSA data shows the most common failures at this mileage are power steering fault (124x the average) and suspension ball joints worn (110x). coil springs broken (107x) and anti-roll bar links worn (33x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Mazda Rx 8 specifically, the DVSA data shows the most common failures at this mileage are emissions failure (78x the average) and suspension ball joints worn (74x). power steering fault (47x) and anti-roll bar links worn (35x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Mazda Rx 8 specifically, the DVSA data shows the most common failures at this mileage are emissions failure (26x the average) and abs fault (21x). significant brake effort recorded with no brake... (9.8x) and headlight fault (9.7x) also appear frequently.
The shift from power steering fault at lower mileages to emissions failure at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Mazda Rx 8 specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Apex seal failure Dangerous
The apex seals are triangular metal strips that seal the tips of the rotary engine's rotor against the housing wall, performing the same function as piston rings in a conventional engine. Affects SE, SE3P.
Suspension component corrosion and failure Dangerous
The RX-8 suffers from widespread suspension component deterioration at rates far exceeding the national fleet average. Affects SE, SE3P; typical independent garage repair cost is £200–£800.
Power steering fluid leak Major
The RX-8 power steering system fails at 123.7 times the fleet average, primarily due to leaks in the hydraulic system. Affects SE, SE3P; typical independent garage repair cost is £200–£600.
Emissions system failure Major
The RX-8 shows exceptionally high emissions failure rates, with levels exceeding limits at This is primarily due to the rotary engine's inherent design challenges with emissions control, catalytic converter degradation from apex seal wear, and secondary air injection system failures. Affects SE, SE3P; typical independent garage repair cost is £300–£800.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Mazda Rx 8 common problems breakdown.
What to check before buying a Mazda Rx 8
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Mazda Rx 8:
Exhaust & Emissions — check for emissions failure. Suspension — check for anti-roll bar links worn, suspension ball joints worn. Lights & Electrics — check for headlight fault.
Beyond the MOT items, ask specifically about apex seal failure and suspension component corrosion and failure. These won't show up on a standard MOT but can be expensive to fix — A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Mazda Rx 8?
Enter the reg to see its full MOT history, mileage records, write-off status, and finance checks.
Mazda Rx 8 MOT FAQs
What are the most common MOT failures on a Mazda Rx 8?
Based on 76,224 DVSA MOT tests, the most common failure is emissions failure — at 78x the national fleet average. Other frequent failures include anti-roll bar links worn and suspension ball joints worn.
Is the Mazda Rx 8 reliable based on MOT data?
The Mazda Rx 8 has 16 MOT failure categories above the fleet average. Specialists also flag apex seal failure as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Mazda Rx 8 most commonly fails on emissions failure and abs fault. Under 60,000 miles, the main issues are power steering fault and suspension ball joints worn.
How do I check a Mazda Rx 8's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.