Why is pre-mixed coolant less expensive than regular coolant?
Actually it is quite a bit more expensive. The price of a gallon may be less, but remember a gallon of concentrated antifreeze produces two-gallons of water/coolant mix at 50/50. Premix offers some advantages, despite the higher price. One is convenience. It is already mixed perfectly with distilled water. This is perfect for adding coolant to a system. It is also infinitely better than the common practice of merely adding water. Premixed coolant keeps the mixture at 50/50, where it needs to be for corrosion protection. It also helps to prevent contaminants, from tap water from entering the system. See also our article on cooling system leaks and proper service.
