Originally posted by SonOfABoss:
Well since I am limited in my knowledge about this, here is something else I heard about synthetic oil, someone told me it doesn't have to be changed, just keep adding it as it burns, which seemed a little strang to me, then someone else told me that synthetic oil still has to be changed every 3K miles just like a conventional oil. Neither true?
That someone is a fool. Synthetics will degrade over time, just like any oil. There are some synthetics that can use drain intervals as high as 20,000 miles. Mobil 1 has been shown to have a slightly extended drain interval (through oil analysis done by CEGers). I do it every 5000 right now, but my next batch is going to Blackstone for analysis and I may go longer/shorter depnding on what the data says.
Bottom line: ALL oils will have to be drained eventually, but synthetics can go longer than conventionals. Some are specifically engineered for much longer.
