How did I get 11 1/2 hours? Luck I guess. :) I filled the ring tightly, removed 7 briquettes from the center and returned them after they were lit, kept temp between 240 and 250 (bottom vents less than 1/8th open, top less than 1/4). At 9 1/2 hrs, foiled butt ( IT was 182 ), at 10 1/2 hrs...