I use Mobil1 Extended Performance with the Mobil1 EP filter, and change after 10,000 miles.
I used to think like Joe.
But now after further research, I believe that anyone who is using synthetics and changes every 3,000 is wasting a lot on unnecessary changes. True, there is no harm done by changing more frequently, but there is also no benefit to doing so, since modern synthetics are capable of performing much longer. I just wanted to post the information for others who might be interested in testing their oil.