You can change your oil as often as you like, it's your money, but you're wasting that money. And 10W-30 oil is not thin--it's just right.
Way back when those mechanics (or their fathers) were learning their trade oil wasn't as good and a 2500 mile change interval was the right thing to do. Modern oils are much better. Here's info that applies to all brands of modern oil.
http://www.tosco.com/internet_pub/re...s/44_tn3_4.pdf
Are you willing to wager $15 on whether or not your oil needs to be changed at 2500 miles? Here's how. When you get 2500 on your present oil don't change it until you get a lab analysis. It costs $15, and the engineer that does the analysis drives one of our trucks and is a frequent contributor to this forum.
http://www.avlube.com/automotive.htm
Ken