A: Engine Ice Hi-Performance Coolant ™ is pre-mixed with de-ionized water. The process of de-ionizing water eliminates all of the impurities that can do harm to your cooling system. Regardless if you are using tap, bottled, distilled, spring or R/O (reverse osmosis) waters, it can still contain minute particles of iron, magnesium, rust, lime and calcium. Many of these waters also contain chemicals, such as chlorine, fluorides and acids. Want proof? Take two different brands of distilled waters and perform your own taste test. They each taste different don’t they? If water were water, why would they be different? It’s because of the varying amounts of chemicals and minerals in these waters. These minerals and chemicals are what is the cause the scarring, scaling and mineral build-ups in your cooling system. Many also attribute these minerals and chemicals to water pump seal and gasket failures.