When weather start to get cold this year, my diesel fiesta (at 100.000km / 621.400ml) do not start at once. Some mornings i try 5 times to make it start. (air temp 1C / 34F) After the start, it never stops. My fuel is "Total Euro-diesel" should i change it? Or should i use a "common rail diesel fuel aid" Some say these fuel aids can clean the fuel system? My air filter is new. but no idea about fuel filter or injections