Combine all ingredients, except tenderloins, in a small mixing bowl; mix well. Set aside.
Trim excess fat from tenderloins. Place tenderloins in a shallow baking dish; pour marinade over meat. Cover and marinate 24 hours in refrigerator, turning occasionally.
Transfer meat to a greased shallow roasting pan; reserve marinade. Bake, uncovered, at 325° for 20 to 25 minutes.
Transfer meat to grill, and insert meat thermometer into thickest part of tenderloin. Grill over medium coals 30 minutes, turning and basting tenderloins occasionally with reserved marinade. Meat is done when meat thermometer registers 170°. Remove tenderloins to a large serving platter; slice and serve warm.