2018 Mercedes-Benz B-Class 1.6L Petrol · RF18 CVC

The vehicle most recently passed its MOT on 2 June 2026 with a minor defect recorded for an inoperative nearside rear registration plate lamp, alongside advisories concerning corrosion and wear on both the front and rear brake discs. Looking at the broader five-year test history, the B-Class has consistently passed every annual inspection without any advisory-free failures or categorised defects, which on the surface suggests a stable and well-maintained mechanical condition. However, a closer examination reveals a gradual accumulation of minor issues and advisories over the past two tests, most notably the persistent registration plate lamp failures on both nearside front and rear lamps across 2025 and 2026, indicating an unresolved electrical concern that the owner has not yet rectified. The brake disc corrosion and wear advisories appearing for the first time in 2026 also warrant close attention, as they represent the onset of component degradation consistent with the vehicle's age and mileage profile. With 56,118 miles recorded over approximately eight years, this B-Class averages around 7,000 miles annually, which sits comfortably within typical usage parameters for a family-oriented Mercedes-Benz of this vintage and suggests neither excessive motorway mileage nor prolonged periods of standing. The mileage progression between tests appears consistent and linear, with no suspicious gaps or sudden accumulations that might indicate clocking or irregular use. This steady usage pattern is mechanically favourable, as it implies regular exercise of the drivetrain, braking system, and suspension components, reducing the likelihood of seized calipers, deteriorated fluid seals, or chronic flat spots in tyres. Nonetheless, the average annual mileage is on the moderate side, meaning some corrosion-related wear, particularly on exposed braking surfaces and underbody components, should still be expected given the vehicle's age. For a prospective buyer, the recurring registration plate lamp defect across two consecutive tests should be treated as a straightforward but indicative fault. While replacing the affected LED or bulb units is typically inexpensive on a B-Class, the persistence of the defect suggests either an electrical connector issue, a corroded earth point, or water ingress into the lamp assembly, all of which merit a physical inspection of the rear lamp housings for moisture, corrosion on the multi-plug connectors, and the condition of the wiring loom. On a test drive, listen for any abnormal sounds from the rear lamp area and verify that all illumination functions operate as intended. The more pressing mechanical concern is the advisory noting corroded and worn front and rear brake discs. Although this was not severe enough to fail the test, brake disc corrosion of this nature on a Mercedes-Benz of this age typically progresses over subsequent months, particularly if the vehicle is used for predominantly short urban journeys. On a test drive, pay close attention to any brake shudder or vibration through the steering wheel during moderate to heavy braking, any pulsation through the brake pedal, and listen for scraping or grinding noises that would indicate the corrosion has advanced to the point of lip formation or pad wear. Inspect the discs visually for deep pitting, excessive lipping around the outer circumference, and check pad material thickness, budgeting for a potential front disc and pad replacement in the near term. Beyond the recorded advisories, several age- and mileage-appropriate inspections should form part of any pre-purchase evaluation. Tyre condition warrants particular attention given that cuts on the nearside front, offside front, and offside rear tyres were flagged in 2025, and tyres fitted at that point will now be approaching the end of their service life or may have already been replaced; verify the production date stamps on any fitted tyres, as rubber compounds degrade with age regardless of tread depth, and inspect the sidewalls for perishing cracking, bulging, or uneven wear patterns that could point to suspension or geometry issues. Given the vehicle's eight-year calendar age, the 12-volt battery should be load-tested, as Mercedes-Benz auxiliary batteries of this vintage frequently fail without warning, particularly if the vehicle has been subject to infrequent long runs. All fluid services are time-sensitive rather than purely mileage-driven on a vehicle of this age, so confirm or budget for a brake fluid renewal, coolant replacement, and automatic transmission fluid and filter service if not recently documented. Finally, inspect the underbody and suspension components for standing corrosion, paying particular attention to the front wishbones, anti-roll bar bushes, and coil springs, all of which are known wear items on the B-Class platform and can produce audible clonks over speed humps and uneven road surfaces when deteriorated.