2018 Mercedes-Benz CLA 1.6L Petrol · AL12 BLS

The 2018 Mercedes-Benz CLA presents a mechanical picture defined by a gradual escalation of issues across successive MOT tests over the past several years, culminating in a recent passing result that still carries a cautionary advisory. The latest test on 2025-09-29 returned a pass, yet the nearside front tyre was noted as worn close to the legal limit, signalling that the vehicle is approaching the threshold where tyre replacement becomes necessary. Earlier in the same timeframe, the 2024-09-18 test failed twice—once with offside rear tyres showing a bulge from structural separation and another with nearside rear tyres exhibiting exposed plies—before the 2023-10-03 test also failed due to severely worn front brake pads and dangerously shallow tread depth on the offside front tyre. This sequence of failures, interspersed with clean passes in 2022 and 2021, demonstrates a clear downward trajectory in roadworthiness quality rather than improvement. At 70,912 miles on a model that is now eight years old, the vehicle accumulates approximately 9,100 miles annually, placing it in a high-usage bracket for its age group. The steady increase in mileage since 2021 aligns with the timing of the multiple test failures, suggesting that cumulative wear on critical systems has progressed consistently rather than remaining stable. Notably, there were three distinct failure events between October 2023 and September 2025, each targeting different subsystems—brakes, tyres, and rear tyres—which indicates that the degradation is systemic rather than confined to a single area. While the annual mileage figure appears reasonable for heavy daily use, the pattern of escalating advisories implies that the vehicle's original design tolerances have been exceeded on at least three occasions over this period. The nearside front tyre wearing close to legal limits warrants immediate attention, as continued operation with this level of wear compromises safety margins and may trigger compulsory replacement within the next few thousand kilometres. The 2024 offside rear tyre bulge and exposed cords represent a serious structural concern that would typically necessitate subframe or wheel arch repairs before the vehicle could be safely registered; such damage often originates from prolonged overload or inadequate suspension support. Additionally, the front brake pads reaching their wear indicator in 2023 and the subsequent nearside front tyre edge wear point to a combination of hard braking cycles and possible misalignment that should be verified during a test drive. Listen for any dragging or knocking sounds when applying the brakes, particularly noting whether the noise varies with load or speed, and inspect the brake disc surface for uneven wear or scoring that might indicate pad failure or rotor damage. Buyers should plan for a thorough physical inspection of the tyre sidewalls for cracks, cuts, or excessive wear beyond the visible edges, and confirm that the nearside front tyre is not progressing toward total loss before committing to purchase. A detailed examination of the rear suspension bushings and tie rods is essential given the reported offside rear tyre bulge, as compromised linkages can exacerbate handling issues and increase the likelihood of further structural fatigue. Finally, verify that the brake system has been inspected for internal leakage or rotor resurfacing needs following the 2023 failure, and consider having the vehicle checked for any signs of subframe corrosion or rust penetration around the wheel arches, especially in areas previously identified as vulnerable to environmental exposure.