No, a higher concentration of Purple Ice than recommended will not harm the cooling system or engine. However, going well beyond 2 ounces of Purple Ice per quart of coolant won’t offer any additional cooling benefit, but may result in some foam generation in the system.
When used with antifreeze, Purple Ice should be added once a year or every 30,000 miles (48,280 km), whichever comes first, in order to maintain proper performance. When using Purple Ice in a cooling system running straight water, Purple Ice should be added once a year or every 15,000 miles (24,140 km), whichever comes first.
When using Purple Ice with a 50/50 antifreeze/water mix, we recommend adding 1 ounce of Purple Ice per quart of cooling system capacity. For straight water (racing) or higher water ratio applications, we recommend adding 2 ounces of Purple Ice per quart of cooling system capacity.
Purple Ice may be added to any antifreeze / water mix; however, testing has shown higher water concentrations yield greater cooling benefits. While Purple Ice does contain corrosion inhibitors as well as lubricants to compensate for a lower antifreeze / water concentration, Royal Purple recommends using a concentration of antifreeze appropriate for the cold winter …