Antifreeze And Engine Coolant Overview

Understanding cooling systems will help you to make correct and accurate service recommendations, resulting in happy customers and increased sales and profit.

Water is the essential heat transfer fluid, but, by itself, can be very corrosive to the cooling system. There are 3 qualities of water, classified by their content of calcium & magnesium:

The terminology used as we discuss coolant system is important. Let’s define a few important term:

Antifreeze

Antifreeze is 95% ethylene glycol (or propylene glycol) that contains an additive package engineered to operate well when mixed between 40 and 60 % with water, the most typical mixture being 50-50.
Antifreeze has to be mixed with water to make coolant before being used. Ethylene glycol is poisonous, and should be handled and stored properly.

Engine Coolant
Engine Coolant is the liquid in an engine that provides heat transfer, i.e. 50 % antifreeze and 50 % water.
Supplemental Coolant Additive

SCA is a chemical package that is added to engine coolant to enhance and extend the life of the coolant.
Coolant has several important functions in the vehicle. It: