I have read in the Alfa Forum the 10W 60 (Selenia or Castrol Racing) with the best oils on the market. Since I drive a lot (900-1000 km a week), and I would like to save fast, I did not want to use the oil. At the moment I drive a 5W 40 or 10W 40 (the previous owner is not quite sure). Can I use the 10W 60 oil easily? Another thing: A car mechanic told me that when changing oil you should fill in diesel instead of oil that car should run 10 min in the stand la Let off (without giving gas) and fill in the other oil. Should be the best way to clean the engine. Is there anything to it? Thank you in advance!