Since the day i discovered this site i have been spending way too much time thinking about oil. I seem to be really researching way to much on specifics on brands of oil for my 05' focus and 04' altima se. It's crazy really! I have decided for the altima it will be 5w30 synpower in the winter and GC in the summer. For the focus i will probably swicth to MC 5w20 syn-blend or 5w20 gtx. I have 5w20 syntec in there now but will probably just use 5w20 dino/blend. This site is addictive but it's too much info. I'm burnt. I will check back periodically too see what's new. WAY TOO MUCH INFORMATION ON THIS SITE.