It's the beginning of fall, and time to consider your coolant.

This is a good time to think about your engine cooling system. Regular inspections and pressure tests of your cooling system are of utmost importance, as is good maintenance by following the vehicle manufacturer’s recommended coolant change intervals.

As time passes, the protective anti-corrosive additives in the antifreeze break down and lose their effectiveness. But antifreeze has two other very important jobs as well:

• It is used to decrease the temperature at which the coolant freezes.

• It is used to raise the temperature at which the coolant will begin to boil.

It is also very important that the proper ratio of water to antifreeze is always maintained. Unless specified otherwise by the vehicle manufacturer, the coolant in most vehicles should consist of a mixture of 50% water and 50% antifreeze before being added to the cooling system. This 50/50 solution not only prevents freezing, but also preserves proper cooling properties.

Also concerning the antifreeze to water mixture ratio: adding more antifreeze to the mix (once again, unless otherwise specified by the vehicle manufacturer) to increase its percentage in the mixture is not better. Generally speaking, after the ratio exceeds more than about 65% antifreeze to 35% water, freeze protection can actually diminish, but even worse, heat dissipation can radically decrease, since the water is the primary substance used for this purpose. Antifreeze itself actually has fairly poor heat transfer characteristics. Having too much antifreeze in the mixture can actually cause engine overheating.

When having your mobile A/C system professionally serviced, insist on proper repair procedures and quality replacement parts. Insist on recovery and recycling so that refrigerant can be reused and not released into the atmosphere.

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