Preheat oven to 450 degrees. Remove neck and giblets from turkey; rinse turkey and pat dry. If desired, loosely stuff turkey. Brush with oil.
Tear off a sheet of foil 2 1/2 times longer than turkey. Place turkey lengthwise in center of foil sheet.
Close foil loosely by overlapping the ends. Turn up short sides of foil to hold in juices. Do not seal airtight. Place foil-wrapped turkey in roasting pan at least 2 inches deep. Insert meat thermometer through foil into thickest part of inner thigh, not touching bone.
Roast turkey until meat thermometer reads 180 degrees. For stuffed turkey, add 30 minutes to roasting time.
Approximate roasting times are: 1 1/2 to 2 1/4 hours for 8- to 12-pound bird; 2 1/4 to 2 3/4 hours for 12- to 16-pound bird; 2 3/4 to 3 1/4 hours for 16- to 20-pound bird and 3 1/4 to 3 3/4 hours for 20- to 24-pound turkey.
To brown turkey, open and turn back foil 30 minutes before roasting is finished. Makes 8 to 32 servings.