2020 Mercedes-Benz E 4.0L Petrol · WA70 PDX

The most recent DVSA MOT test for this 2020 Mercedes-Benz E-Class was conducted on 2 February 2026 and resulted in a pass with no defects or advisories recorded. The immediate prior test, however, was a failure on 26 January 2026 for an exhaust carbon monoxide content exceeding default thresholds after the second fast idle measurement, classified as a Major defect under item 8.2.1.2 (b). The vehicle then returned to the testing station within a week and passed cleanly, suggesting that the failure was addressed through remedial work rather than being a symptom of deeper mechanical deterioration. With two further passes recorded in February 2025 and November 2023, the overall test history points to a broadly stable maintenance profile, though the recent emission failure warrants closer attention to the catalyst, lambda sensors, and engine management condition. With 55,798 miles recorded on a six-year-old vehicle, the annual usage works out at approximately 9,300 miles per year, which sits comfortably within the typical range for a UK executive saloon of this vintage. The mileage progression between tests does not indicate any unusual gaps or rapid accumulation that would suggest extended periods of standing or conversely high-mileage abuse. Consistent moderate usage generally benefits complex vehicles such as the E-Class, keeping seals lubricated, the diesel or petrol particulate system active, and preventing the brake and suspension components from seizing through inactivity. That said, even average-mileage examples of this age begin to show fatigue in wear-and-tear items such as suspension bushes, coil springs, and flexible engine mounts, so a physical inspection remains essential. Given that the MOT record is largely clean but shows one resolved emission failure, a prospective buyer should focus particular attention on the exhaust aftertreatment system. It would be prudent to check for any warning lights on the dashboard, particularly the check engine management light, and to confirm that the vehicle has been serviced in accordance with Mercedes-Benz intervals, as neglected oil changes or air filter replacement can contribute to elevated carbon monoxide readings. A test drive should include extended steady-state running to allow the catalyst to reach operating temperature, listening for any irregular exhaust note or whistling that could indicate a failing lambda sensor or compromised catalytic converter. Should the advisory or rectification history be available from the selling dealer, confirming exactly what work resolved the January 2026 failure would provide further reassurance. Beyond the emission concern, practical age-related checks are advisable on any six-year-old E-Class. Tyres should be inspected for tread depth and, importantly, for sidewall cracking or perishing consistent with age, even if tread remains adequate. Brake discs should be examined for corrosion lips and the calipers for any signs of binding, particularly given that the vehicle has covered enough mileage for pad and disc replacement to have likely occurred at least once. The 12V battery health should be verified, as Mercedes-Benz vehicles of this era are sensitive to voltage drops that can trigger spurious warning messages and module faults. Finally, verify that time-based servicing items such as brake fluid, coolant, and transmission fluid have been renewed within their calendar intervals, and ensure the digital service history within the Mercedes-Benz system is complete and matches the vehicle's recorded mileage.