CoolDrive coolant advice

Engine coolant is a fluid mixture that aids heat transfer plus ensures the optimum operating temperature of most fossil fuel powered engines. Its primary function is to keep the engine at a constant safe operating temperature, but also, with the addition of other chemicals called inhibitors, to control the formation of scale and rust.

Inhibitors also prevent cavitation, which is oxidation from water passing through the cooling system. Anti-freeze/anti-boil coolants lower the freezing point of the coolant while raising the boiling point.

Corrosion inhibitors have little or no anti-freeze/anti-boil properties, and are used primarily to protect surface materials in the cooling system from corrosion.

Type A and Type B are the two main categories of coolant. Type A has an anti-freeze/anti-boil package included, present as ethylene glycol or similar; an additive package raises the boiling point of the water and lowers the freezing point.

Type B does not have an anti-freeze/ anti-boil additive package added, and is true corrosion inhibitor-only, with no or little AF/AB properties. There are different formulations of both Type A and Type B. Some are not compatible.

A good coolant will provide the following:

• Good heat transfer.

• Protection against deposits.

• High temperature protection.

• Safe to use with hard water. • Won’t damage and be neutral with internal components.

• Reduced foaming tendency. A bad coolant will provide none of the above.

Just because a coolant is coloured doesn’t mean it’s an anti-freeze/anti-boil product or a corrosion inhibitor. The colour in coolant is a dye and should never be used to distinguish the type of coolant.

Many OEM manufacturers add dye in their coolant mainly to aid in identification of brand (specific to that make) or type of coolant. Aftermarket manufacturers usually use dye to differentiate the type.

Type A or Type B should be clearly labelled on the packaging. The OEM manufacturer will indicate what is suitable for the vehicle, and this is usually found in the owner’s service appendix.

Some type A coolants are not compatible with each other. Organic Acid Technology (OAT) coolants are not compatible with conventional type antifreeze types. Also available are hybrid types, which combine the properties of OAT with conventional types, and these should not be used in systems that contain conventional type A anti-freeze/ anti-boil coolants.

So if there is any uncertainty, the best way to make sure is to completely flush and clean the coolant system using a good quality cooling system flush, before a new fill of anti- freeze/anti -boil or corrosion inhibitor.