Audi A4 Owners Manual

General maintenance / Fuel and filling the tank / Diesel

Diesel fuel

Please note the information on the inside of the fuel tank flap.

Diesel fuel must comply with the European EN 590 standard. It must have a cetane number (CN) of at least 51. The cetane number indicates the ignition quality of the diesel fuel.

Winter-grade diesel

Diesel fuel can thicken in winter. For this reason petrol stations in some countries also offer winter diesel.

Audi A4: Diesel. Caution

  • • The vehicle is not designed for the use of biodiesel (FAME fuel). The fuel system would be damaged if you used biodiesel.
  • • Do not mix fuel additives (“thinners”, petrol or similar additives) with the diesel fuel.
  • • If poor-quality diesel fuel is used, it may be necessary to drain the water separator on the fuel filter more frequently than is specified in the Service Schedule. We recommend having this done by a specialist workshop. If water is allowed to collect in the filter, this can cause engine performance problems.

© 2024 All Rights Reserved.