Im with nova dude, but I change oil every 3k. I mainly use what I use because its cost effective. My oil changes cost me less then 7 bux....and thats with a 7qt pan. Buy in bulk....you cant go wrong.
buying in bulk is the way to go... I buy my K&N filters online... 10 pack for $49.99, and buy my oil at Costco... 12 QT case for like $5! now that's cost efficient!
-Kendall is great oil... but expensive, and hard to find in a store...
-I change my oil every 2500 miles at the most! I can't believe you guys and your 5K-10K miles between changes... that's so bad if you drive your car hard at all, and face it, that's why you own a mustang!
-although I will admit, 2500 is a little soon some of the time, but it keeps my engine and all parts hella clean (that and the chevron additives)