I noticed my over flow tank was almost empty and was wondering if I could use a long life all makes and models to top it off. I have a full gallon of napa all makes and models also a gallon of supertech all makes and models. Or should I drain all the old antifreeze out and fill with the napa stuff. The car has 60,000 miles on it now and I know Hyundai said its antifreeze is good for 120,000 miles. So if I change it now it seems to me to be a waste. So top it off or change it all what do u guys think.