In a blender, combine the soy sauce, honey, vinegar, ginger, garlic powder, and vegetable oil.
Lay steak in a shallow glass or ceramic dish. Pierce both sides of the steak with a sharp fork. Pour marinade over steak, then turn and coat the other side. Cover, and refrigerate 8 hours, or overnight.
Preheat grill for high heat.
Place grate on highest level, and brush lightly with oil. Place steaks on the grill, and discard marinade. Grill steak for 10 minutes, turning once, or to desired doneness.
