Preheat a smoker to 225 to 250 degrees F (110 to 120 degrees C).

Pat turkey dry thoroughly with paper towels—inside and out. This removes excess moisture and also helps skin crisp during roasting.

Rub crushed garlic over the outside of the turkey, and sprinkle with seasoned salt. Transfer to a disposable roasting pan.

Fill the turkey cavity with butter, cola, apple, onion, garlic powder, salt, and pepper. Cover turkey loosely with foil.

Add wood chips to the smoker according to the manufacturer's directions. Place the roasting pan in the preheated smoker. Smoke the turkey, basting every 1 to 2 hours with juices from the bottom of the roasting pan, for 5 hours.

Add more wood chips if desired. Continue smoking and basting, until turkey is no longer pink at the bone and the juices run clear, about 4 to 5 more hours. An instant-read thermometer inserted into the thickest part of the thigh, near the bone, should read 180 degrees F (80 degrees C). Remove from the smoker, tent loosely with foil, and let rest for 20 minutes before carving.