Water, Coolant & Additives

Doing a little homework on the right water to use in your cooling system can prevent expensive problems down the road.

Sometimes even the simplest components may be where the problem lies. Water, coolant, and additives are arguably the simplest components of the cooling system but they too must be carefully maintained and watched over. To get the inside on water and coolants we rounded up the answers from our Road Tour partners at AMSOIL Inc.

Changing to straight water engine coolant also comes with a secondary benefit for racing applications: running cooler. Water has almost twice the heat transfer capability as antifreeze, making it the ideal coolant for high-performance street or racing engines. The result is a cooler running engine and higher performance.

But all this good comes with a trade out that leads to the "death" of any street cooling system—water is very corrosive. Water also contains contaminants that cause scales to form and over time these scales have an insulating effect, which reduces heat transfer and causes overheating. Scales only 1/16 inch thick can reduce heat transfer by 40 percent, causing engine overheating and hot spots that result in detonation.

So in order to prevent corrosion and scale buildup, it is important to select the right water. Tap water may be safe to drink, but contains calcium, magnesium, chloride, fluoride, and other materials that are corrosive to cooling systems and cause scale buildup. Well water is even worse. It often contains the same contaminants as tap water, but can also contain sulfate, iron, and silica. These materials can, under some conditions, cause rapid degradation of coolant pH, and severe corrosion and scale buildup.

AMSOIL Inc. has conducted extensive research in the area of straight water engine coolant. Their tests show that the absolute best water to use is reverse osmosis (RO) water or bottled drinking water. This water is purified by passing through a selective membrane that removes all impurities that cause scale buildup. And unlike distilled or deionized (DI) water, RO water is electrochemically balanced. This means that it is stable and won't strip electrons from the metals in your cooling system in order to regain stability, as can happen with distilled or DI water.

In a Temperature Reduction Dynamometer Test, water treated with Dominator Coolant Boost provided a 19 degrees F temperature reduction. It also easily passed the Aluminum Corrosion Test (ASTM D-4340). In the Metal Corrosion Test (ASTM D-2570), which tests corrosion in all metals common to cooling systems, AMSOIL Inc. Dominator Coolant Boost also showed a significantly reduced weight loss.

Dominator Coolant Boost is recommended both for racing applications using straight water coolant and hot rod applications using 50/50 coolant/water mixtures.

AMSOIL Inc. Propylene Glycol Antifreeze and Engine Coolant is suitable for use up to seven years or 250,000 miles in a hot rod. (Not many of those around!) The new antifreeze/coolant is resistant to corrosion of aluminum, iron surfaces, and solder points.