If necessary, unbind legs of turkey. Rinse and dry turkey with paper towels. Place turkey into a roasting pan with a lid, and rub the oil all over the turkey, inside and out. Stuff the body and neck cavities of the turkey with the apple quarters; arrange whole apples around the turkey in the roasting pan. Scatter any extra apple quarters into the pan. Cover the roasting pan.
Roast in the preheated oven until the skin is browned and the meat is beginning to separate from the legs, 2 1/2 to 3 hours. Remove lid in last 20 minutes of roasting if needed to brown skin. Use pan drippings for gravy, if desired.
Be sure not to use too large of a roasting pan. If using an aluminum (throw-away) roasting pan, tent the aluminum foil placed over the turkey so that it does not touch the turkey; however, it is necessary to ensure that the aluminum foil is as "sealed" as possible.
Baking time varies based on the size of the turkey and the kind of oven used; if in doubt, follow the rule of thumb of 15 minutes per pound of turkey. However, I have found that this recipe cooks remarkably fast.
I never add salt to this recipe, even when making the gravy.