Examinations of Extended Life Heavy Duty Engine Coolant Filters
Since 1996 engine coolants and/or coolant management programs that offer extended service have been heavily promoted. Coolant chemistry is often affected by both depletion and dilution of important protective additives. Two different strategies are prevalent in the marketplace. The first utilizes advanced fully formulated conventionally inhibited ethylene glycol coolants with a controlled-delivery coolant filter that both filters the fluid and provides replenishment of corrosion inhibition chemistry as the coolant ages to greatly extend the life of the coolant compared to earlier practices. The second alternative employs the use of ethylene glycol inhibited with fully formulated chemistry dependant on aliphatic or cyclic carboxylic acids that are sometimes combined with inorganic inhibitors (sometimes called organic acid or hybrid organic acid technologies).