If you really want to run cool, use 100% water and add a rust inhibitor and water wetter... every drop of anti freeze reduces the efficiency of your cooling system. The odds of your car freezing in this area ---> also Zero..
Before Mister Know-It-All chimes in:
The Importance of Coolant
Another easy way to protect your engine
by Debbie Murphy
Whether you call it engine coolant or
antifreeze, the fluid in your radiator multi-tasks, circulating throughout your engine block and keeping the works purring like a kitten.
What is Coolant?
Generally, coolant is a half-and-half mixture of a form of glycol and water. The glycol represents the
antifreeze element of the mix, guaranteeing that the fluid doesn't turn into solid ice under harsh winter conditions. On the other hand, glycol also prevents the coolant from reaching the boiling point in Death Valley heat; it keeps engine temperatures stable under all climate extremes and driving conditions by transferring heat from the engine to the radiator.
Interestingly, pure water actually transfers heat better than coolant (that's why you see straight water used in the radiators of some types of racecars). However, coolant/antifreeze includes additional additives that prevent rust and corrosion in the radiator, engine and the vehicle's heater.
http://www.valvoline.com/carcare/art...cid=3&scccid=4