It's made to be used only with water as the coolant (as in race cars), not with anti-freeze mixtures; it's a corrosion inhibitor (which is already in anti-freeze). More marketing hype, relying on the word "race".
From the Valvoline website:
Valvoline’s Zerex Racing Super Coolant is a NASCAR
proven cooling system corrosion inhibitor concentrate. It is
added to water at 10% by volume to cool and protect racing
internal combustion engines requiring no freeze protection.
Zerex Racing Super Coolant provides a 25% improvement in
heat transfer over conventional glycol based engine coolants.
It maintains the cleanliness of heat exchange surfaces by
preventing rust and corrosion product buildup, unlike plain
Zerex Racing Super Coolant gives excellent protection against
cavitation and corrosion to all metals commonly used in
automotive cooling systems. Aluminum, ferrous metals, and
yellow metals are well protected.
Zerex Racing Super Coolant
prolongs the working life of water pumps and heat exchangers.
Zerex Racing Super Coolant should be diluted with tap,
demineralized or deionized water. The dilution water should be
a clear and free of suspended matter or solids.
Solutions to cooling problems come in boxes, not bottles.