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Antifreeze and Coolants

With manufacturers improving engine technologies the need for application specific antifreeze and coolants has become necessary to maintain the smooth running of an engine


Why are application specific coolants now coming into the market?

Because they have to absorb and disperse the much greater heat generated by contemporary engines, while providing equal protection to the multitude of elements and components they contact within different engine and cooling systems. Today, no single coolant technology can accomplish this for all makes and models. This creates the necessity to have engine specific coolants available.

The important difference between the various types is in their additive (corrosion/erosion) inhibitor packages. Corrosion inhibitor packages are chemicals that react with metal surfaces to produce protective layers that are stable for an extended period. The layers form a molecular barrier and prevent oxygen from reaching the metal surface and causing corrosion.

Since more than one inhibitor is required, coolants from BASF contain inhibitor packages. Inhibitors have to be mixed in such a way that they do not neutralize each other. That’s where the secret of developing a usable engine coolant lies. Take an engine whose cooling system includes both cast iron and aluminium components. Sodium nitrite is a very effective inhibitor for iron materials but on the other hand this substance attacks aluminium. A very good inhibitor for aluminium is sodium nitrate; however, sodium nitrate attacks iron. Finding the right balance is the key to producing a premium Antifreeze.

The only way to be 100% sure that the correct coolant is used for a particular car is by using Comma’s Application Guide. A good example is applications for the BMW Mini, which requires Xstream G48 for the petrol version and Xstream G30 for the diesel version from 2007 onwards.

What can happen if OEM-specification coolants are not used?

Corrosion (rusting) and cavitational erosion (pitting) of water pumps, wet liners, radiators and other components leading to potential failure, overheating due to build-up of deposits throughout the system, damage/porosity to plastic and rubber components and seals causing leaks leading too potential system failure.

Are OEM approved Xstream coolants more expensive than standard MEG? Yes, but they last longer than traditional aftermarket British Standard ME G (3-5 years v 2 years), and provide the best possible protection for consumers’ cars. They are approved by the vehicle’s manufacturer and the same products as the one fitted by the engine manufacturer. Comma now also, includes “Next-Service-Due” stickers on all 5L & 20L Xstream packs to remind customers when to come back for their next coolant check or change and which coolants has been used.

Can we expect to see wider take-up by vehicle manufacturers of the latest coolant technology? History suggests that where VAG and the other German manufacturers lead, other vehicle manufacturers tend to follow suit. Manufacturer specific engines oils provide a good model for the trend: e.g. five different Comma 5w-30s to cater for the engine-specific requirements of five different manufacturers. So the priority for workshops is always to specify precisely the correct coolant for every application. The example of the BMW Mini indicates that this is not always as straightforward as it may as first appear. The petrol Mini uses a BMW engine; the diesel version uses an engine supplied by Peugeot! In all circumstances, Comma’s Xstream range, supported by industry leading coolant application data, provides all the solutions.

Why are OEM approved Antifreeze the better choice?

Only Comma’s Xstream products filled with Glysantin from BASF carry the official manufacturer approvals. A coolant has to pass an average of 30 different tests before it is approved by the car manufacturer.

These include corrosion tests and compatibility tests with original components of the cooling system. In addition, measurements of different liquid parameters such as the coolant’s density, pH and tendency to foam are performed. To test the compatibility with polymers, plastic parts from the cooling system are immersed in boiling coolant for up to 1,000 hours and then examined for changes. Another important part of the approval process is long-duration tests on the engine test bench.

Only when the coolant has successfully undergone all the tests it is approved by the vehicle manufacturer. The entire process takes three to five years and can easily cost in excess of £1 million.

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