How long is full synthetic oil good for?

I have bought a whole carton of valvoline full synthetic oil back in 2003, is there an expiration date for oil or something?How long is full synthetic oil good for?
No, your oil is still good, and most people only change their oil every 5,000 miles using that type oil, hope this helps.How long is full synthetic oil good for?
The oil is still good, but some of the additives will have settled to the bottom, so I would either shake it up before pouring or turn the cans upside down over night before using.





REMEMBER: you still need to change it at the right intervals. You change oil because of contamination, NOT because it's worn out.





http://www.nordicgroup.us/oil.htm#How%20鈥?/a>