I ended up finding 0w-20 at a walmart in huntington beach (last 5 quarts actually). Mobil 1 seems to have a search by grade and sure enough the 0w-20 results in a much smaller list of stores but the first one I called on the list had it so I was happy. The search page can be found on their site but it's http://web.sa.mapquest.com/mobil1/?tempset=search.