RE: Mazda5 oil curiosity
 

Check out Bob like the previous poster has said.

AS to using 5W-20 or voiding the warranty, well that is bull puckey.

ANY motor oil that MEETS OR EXCEDES the manufacturer spec can be used.

Since mine is a lease, I'll use what ever the dealer puts in, but every one of my own cars gets Mobil One extended release, and I go about 10K on an oil change and I have the oil tested every 40K miles or if I suspect something funny.