I added Watter Wetter to the Toyota Red in my Camry, and very quickly got the cooling system "sludge," both in the oflo tank and in the radiator too. It looked awful, but caused no noticeable cooling symptoms. Envision greasy fudge, halfway between vanilla and chocolate, and that's what I had. After a flush and refill, I decided to try Royal Purple's Purple Ice product, which advertises essentially the same cooling benefit. No problem with the PI.