Wal-mart carries Mobil 1 15W-50 (not the extended performance line) for @ $25/gallon.

http://www.mobiloil.com/USA-English/...1_15W-50_.aspx

Not the same as the old extended performance line, but should be close.

http://www.mobiloil.com/USA-English/...AQs.aspx#FAQs3