If there is any particular part of an automobile that rarely gets real preventative maintenance, it has to be the cooling system. One old saying that translates into just about any language is; "If it ain't broke, don't fix it". Like I said, a car's cooling system has to be one of the best examples of that philosophy.

One of the biggest reasons we tend to overlook the cooling system is that from external appearances, it does not seem to be doing much. Nothing could be further from the truth. The internal combustion engine is really not a very efficient power plant. A lot of the energy we pump in the form of fuel must be gotten rid of through the radiator. In supercharged cars, this heat exchange becomes critical since supercharging increases temperatures in the combustion chamber even higher, which requires higher fuel octane to prevent pre-ignition and subsequent knock. In lay terms, the radiator in your car gets rid of two to three times the amount of energy (in the form of heat) than is produced for use at the car's rear wheels.

Now here is a real kicker. We have been brainwashed into believing that if you do not use a 50/50 mixture of an ethylene glycol based anti-freeze in your radiator year round, you are a negligent car owner. Dig this, under moderate load conditions, each percent of anti-freeze used in your radiator increases cylinder head temperatures by one degree Fahrenheit, when compared to plain water. The use of a 50/50 mixture in your radiator translates into higher cylinder temperatures, which translates into the need for higher octane in your car. Typically by 3.5 octane numbers or more.

Fact: A 50/50 mixture of anti-freeze has about four times the viscosity, (it does not flow as easily through the cooling system) and only 70% of the thermal conductivity of water. When the advertisement says "anti-freeze, anti-boil", what they are saying is that a 50/50 mixture of anti-freeze boils at a much higher temperature than plain water does. You can also say the same thing about a 50/50 mixture of sugar water.  It does not mean that it increases your radiator's ability to get rid of heat.

Now there are other considerations when using plain water as an automotive coolant. The majority of modern engines use aluminum extensively in their construction. Next to magnesium, water dissolves aluminum better than just about any metal (including zinc). Water is not called the "universal solvent" for nothing'. You must provide some form of rust and corrosion inhibitor. You must also remember that most local tap water has a very high "hardness" rating (As measured by parts per million of calcium carbonate) Why is hard water bad? It has a very high surface tension. Why is a high surface tension bad? It prevents the water from coating the internal passageways of the cooling system and thusly prevents a higher rate of heat transfer. It can also result in localized boiling inside the cylinder heads even though the bulk of the coolant is well below the boiling point. This localized boiling forms vapor bubbles, which collapse when they contact cooler liquids. This collapse causes shock waves, which can damage the cooling system.  Hard water also increases "foaming" inside the cooling system. Foaming can lead to cavitation in the water pump and cylinder head, (more bubbles) which dramatically reduces heat exchange. Thusly a commercially available "water wetter" is in order. Preferably one with good rust and corrosion control as well.

My own personal "poison" is distilled water from the supermarket, and Red Line WaterWetter®. Distilled water has no minerals, thusly an already low surface tension. Red Line WaterWetter® reduces that surface tension to an even greater extent. That translates into even better heat exchange. It also protects the internal cooling system from corrosion. I also trust the quality of Red Line products.

Now here's the part where you really need to pay attention. If you have an air conditioner in your car you need to use