Wynn’s Coolants & Antifreeze

Some COOL Facts

What you didn’t know about Antifreeze!

Most automotive antifreezes are Ethylene Glycol based, an essential chemical to prevent the radiator water from freezing and also provides some lubrication benefits.

At a 40% ratio to de-ionized water, glycol can drop the freezing point down to about -45o C, never to be experienced here in South Africa, so why is an antifreeze so important?

According to studies performed in the US, over 60% of mechanical break-down is directly attributed to cooling system failure. The radiator and cooling system is required to remove 33% of combustion heat from the engine block to maintain optimal operating conditions.
So perhaps it’s more appropriate for us to rather talk about antifreeze as a coolant, after-all, this is its most important function.

There are two main types of coolant, traditional/ inorganic or silicate (Type B) coolants and the OAT Organic Acid Technology or extended life (Type D) coolants.

Both types are ethylene glycol based but differ quite dramatically in the corrosive inhibitor and additive technology. These are essential ingredients to prevent not only corrosion but cavitation pitting, foaming, calcareous scale deposits as well as providing pH stability.

There is no doubt that the newer OAT type is the coolant of choice for most OEMs today, but what if you choose to use this in your old classic?

From about 1980, radiators started to change from copper/brass cores to aluminium which has both weight and environmental benefits and now the most common radiator in use.

OAT coolants are generally suitable for these radiators but not necessarily for the older copper and brass cores with older gaskets and seals which can be incompatible with the carboxylate additives in the OAT Coolant.

So if you have an old classic, stick to the traditional Type B coolant, it might get “used up” quicker as the silicate is chemically depleted, but will not cause leaks or damage the radiator core.

The coolants are often distinguishable by colour; traditional type B coolants in blues or greens while OAT’s are often red, pink or orange.

It’s always best practice to flush and drain the radiator before changing any coolant as silicates and carboxylate additives are not always compatible and scale deposits often need to be chemical removed from the radiator surface in order to restore optimum heat transfer.