2020 Mercedes-Benz C 300 Sport Edition DE Auto 1.9L Electric diesel · OV20 EUR

The 2.0-litre diesel C 300 should return around 50-55 mpg in mixed driving, though high-mileage examples may achieve less. Road tax for a Euro 6 diesel in this band is typically £170-£190 per year. Insurance for a C 300 Sport Edition is likely to sit in groups 30-34, so premiums for a 40-year-old driver could be £700-£900 annually. With 175,487 miles recorded, budget for higher maintenance costs — including a timing chain service if not already done, brake discs and pads, and potential suspension component replacement. Estimated annual running costs are around £2,400-£2,900 including fuel, tax, insurance, and maintenance.

Start with a thorough test drive paying attention to any diesel knock or rattle on cold start, which could indicate timing chain stretch — a known issue on Mercedes OM654 diesel engines. Inspect the front tyres closely, as the 2024 advisory noted edge wear and the 2026 test flagged a slightly damaged nearside front outer tyre; uneven wear can suggest suspension or alignment issues. Have the rear brake pads measured, as the most recent MOT noted they are wearing thin. Check the EGR valve and DPF for warning lights, and ask for a diagnostic scan to identify any stored fault codes. Inspect the underside for corrosion, oil leaks, and condition of the dual-mass flywheel by listening for rattling on overrun. Finally, verify that all previous advisories have been addressed, particularly the 2025 test which recorded no defects — ask to see receipts for any work carried out between tests.