I have always used the 20min per pound,but i also use the turkey rosting bags and have for years.I never get a dry turkey because the juces stay in the bag and you get lots of juices for gravy. It is now said to use two smaller turkeys instead of one lg.It makes since because the timing would be the same for both but not as long as a lrg bird. We are trying it this year since we will be having 12 or more for dinner.