Have a 2009 Corolla that was coming up on 110K. Coolant was nice and clear red. But I wanted to do a drain and fill. Bought Prestone Asian 50/50 ... was same clear red color coming out of bottle. Six months later, color is orange/red and not as clear. Anyone else had experience with Prestone Asian. Car runs fine but the color change concerns me. Think I'm gonna drain and re-fill with Valvoline Asian 50/50