I bought a new WP from Napa for $94 and bought four gallons of Zerex GO-5 (HOAT) anitifreeze. I wound up only using a little over 6 gallons mixed. Be carefull because it take some time to gurgle out all the air bubbles. It got really hot on my first I'm guessing from a big bubble at the water pump. Pulled over an filled it up and its been good ever since.