I realize this is an old discussion, but one point that wasn't touched on and it should be noted, yes water is better for cooling, but anti-freeze/water 50/50 raises the boiling point to about 220*F, our motors should run between 190-200*F for optimal fuel efficiency at operating temp, this becomes even more important for those of us travelling in high altitude. It also should be noted that pressure inside the cooling system also raises the boiling temp, but a 50/50 mix is ideal in almost all situations/conditions regardless of outside temp and elevation.