Oil Weight, etc..

Has anyone used 0W30 in their truck? Does it really improve fuel economy that much? I searched the forums for 0w30 and oil weight, but got nothing relevant so Im starting a new thread.

Also, I have 160k miles on my 4.8 and want to know if there would be any benefit switching to synthetic oil now...BTW if you use synthetic Advance Auto has buy 1 get one free valovoline syn power full synth oil.

I have gone to synthetic in several vehicles. I don't know if just the crankcase oil is enough to tell but I think it does. I also change the differential fluid to synthetic. That does seem to make a differance. It is never to late to try synthetic. I have been running synthetic for at least 20 years and never had a lubercation failure.