A7 3.0TDI quattro EZ07/2011 Yesterday morning at – 13 degrees ( at night max -16 degrees ) my A7 3.0TDI started miserable. Before the programmed preheating had already died after a few minutes. Further attempts to turn on the preheating failed – then the preheating was dead (workshop symbol in the display) . After another start was then everything that has to do with MMI (Navi, radio etc.) also dead . Follow : 1.5 days workshop stay. Today I was able to pick up my A7 again – S Tandheizung runs again. MMI goes again ( “Only reset necessary”. Everything free of charge and with an adventurous explanation: I would have fuelled wrong fuel – JET Diesel and AUDI now expressly recommends to me the superteure ARAL Ultimate ! As an engine engineer I know very well the differences in diesel qualities incl. winter diesel. However, it is unknown to me that any German car company develops vehicles that do not comply with the valid diesel fuel standard DIN EN590 mmt. Up to -20 degrees this winter diesel must always fnunctionate, otherwise we would have had to stop the last days 60% of our German vehicles tomorrow…. After this Audi speech – the protocols of the workshop with the AUDI plant were shown to me – I even have to worry about my engine after a refuelling at JET ????? Are there similar statements on the part of Audi that you have to refuel special fuels? Are other lantern parkers with new A6 / A6 also missing? Here is the usual description for winter diesel: The filterability limit (useability) of the diesel fuel is regulated by the CFPP value depending on the season in the EN 590 – the winter diesel from mid-November to the end of February must achieve a CFPP value of at least ?20 °C. Many oil companies typically lower the CFPP value to ?22 to even -33 °C in the winter months.