Quick Heat is specially formulated to get the heat from your engine into your heating system faster in frigid climates. This does two things. . Gets you warmer faster and melts ice and frost from windows more quickly. Quick Heat is safe to mix with all types of anti-freeze. Just simply pour one bottle into your radiator/cooling system and feel the warmth. To get a little technical, what Quick Heat does, is reduces the surface tension of the coolant in your system and stops tiny bubbles from forming (cavitation), making it more efficient in the transfer of heat from the coolant to your heating system. You don't need to change your coolant in the summer after using Quick Heat. Your system will maintain the same heat transfer efficiency and actually lower coolant temps in hot climates. 16 oz.