Preheat oven to 325 degrees. Line a roasting pan, at least 2 inches deep, with foil; set aside. Remove neck and giblets from turkey; rinse turkey and pat dry. Place turkey in foil-lined roasting pan. If desired, loosely stuff turkey. Brush with oil. Insert meat thermometer into thickest part of thigh, not touching the bone.
Make a foil tent by placing a sheet of foil over turkey, leaving 1 inch between top of turkey and foil tent for heat circulation. Crimp foil onto long sides of pan.
Roast turkey until meat thermometer reads 180 degrees. Approximate roasting times are: 2 1/2 to 3 hours for 8- to 12-pound turkey; 3 to 3 1/2 hours for 12- to 16-pound turkey; 3 1/2 to 4 hours for 16- to 20-pound turkey and 4 to 5 hours for 20- to 24-pound bird. For stuffed turkey, add 30 minutes to roasting time.
To brown turkey, remove foil tent after 1 hour of roasting. Makes 8 to 32 servings.