Would running synthetic oil provide more protection and longevity to our little xB powerplants?

Just cruising down the interstate at 75 has the engine turning close to 4000 rpm. I know there isn't much I can do about that. Is it harmful on the engine to be turning those speeds for sustained amounts of time, and would a syntetic help at all?

 

lol go to the manufacuers site of sinth oils and read ther specs and thing i think you will be very informed after doing that...

 

do a forum search on synthetic oil ... volumes have been written on it already