2015 Mazda 6 2.2L Diesel · SM15 OCO

The 2015 Mazda 6 passed its most recent MOT on 6 October 2025 at 104,024 miles, but the maintenance trend is not reassuring. That test flagged a nearside front suspension arm ball joint with slight play and a severely deteriorated dust cover, along with worn front suspension arm pins or bushes. A nail in the nearside rear tyre and a cut in the offside rear tyre were also noted, and the exhaust emitted excessive smoke or vapour. These advisories point to deferred suspension upkeep and a neglected exhaust condition rather than routine consumable wear alone. The mileage progression tells a story of uneven use. Between the clean pass on 5 August 2023 at 81,381 miles and the failed test on 8 October 2024 at 94,993 miles, the car covered roughly 13,600 miles in just over a year. That is a sharp increase compared with the earlier average of around 9,500 miles per year. The jump suggests a period of heavier use or a catch-up in mileage after a quieter spell, which may explain the sudden appearance of corrosion-related failures on the rear lower suspension arms at the October 2024 test. A buyer should focus on the rear suspension and subframe area. The October 2024 failure for corroded and seriously weakened nearside and offside rear lower suspension arms is a structural concern, not a minor rust surface issue. Even though the car passed in October 2025, corrosion of this nature can recur or worsen rapidly, especially if the vehicle has been used on salted roads. Inspect the rear subframe mounting points, lower arm attachment points, and any visible seam welds for fresh corrosion or repairs. The front end also warrants close attention. The October 2025 advisories on the nearside front ball joint and front suspension arm bushes suggest the front end is now wearing through its serviceable life. Check for uneven tyre wear, clunking over bumps, and any play in the front suspension. The exhaust smoke noted in the latest test should not be dismissed as trivial. A compression test and a check of the exhaust system for oil fouling or coolant ingress would help rule out internal engine wear. Tyre condition has been a recurring theme across multiple tests, so verify the age, tread depth, and sidewall integrity of all four tyres and the spare before purchase.