It should be 15 on the button. I bought 15 quarts (well 16 actually b/c I did the flush) and it took 'em all.
I drained the old oil, and took the filter off and drained it. Put filter back on...put in one quart, cranked it over a few times, drained, replaced w/ new filter, and filled w/ 15 quarts. Level was right in the middle on the stick.