UNDERSTANDING COOLANT 101
We know a thing or two about engine coolant, we supply over 100,00L of coolant a year. We have the capacity and knowledge to service all areas of industry from the backyard mechanic to the largest world class mining operations. In relation to long life engine coolant, apart from wholesale to over the counter sales, we have since 1997 been servicing major mines in Australia and PNG. Our stock holdings are from 500ml bottles to 1,000 litre bulk containers. We back this up with extensive knowledge as to how and why coolants work, and together with direct access to the manufacturer for technical and training information, are able to answer queries and offer professional support to all levels involved in an operation using coolant. With major engine manufactures agreeing that up to 40% of engine failure are attributed to cooling system failure can you not afford to get the very best advice from FCP Solutions a truly specialist supplier of engine coolants exclusively from PrixMax Australia since 1996.
Potential cost saving when using water based coolant VS
Anti freeze based coolant
WHO ARE PRIXMAX
PrixMax is a recognised leader in the coolants market and has been developing and manufacturing premium quality coolants in Australia since 1994. Operating out of a specialised manufacturing facility that is accredited against international standards such as ISO 9001:2015 and ISO 14001:2015, PrixMax is committed to developing leading technology products to suit any vehicle and application. The company also operates one of Australia’s only dedicated coolant testing and research laboratories, where they focus on providing state-of-the-art quality products, backed up by industry leading technical support.
In the 1990s, PrixMax pioneered the release of organic additive technology coolants in Australia with their “long life organic coolant” product range, comprising the water-based product known as RCP (Radiator Corrosion Protector) and the anti-freeze product MEG95. Since then, PrixMax’s long life coolants have become arguably the most extensively field tested products of their kind in Australia, recording literally hundreds of thousands of hours of successful performance in the field across a wide range of Original Equipment Manufacturer (OEM) engines. Today, PrixMax continues to engineer innovative coolant solutions to meet the increasingly complex demands of modern engine cooling systems.
- OAT = Organic Additive Technology inhibitor package
- Hybrid = Combination of OAT and conventional chemistry inhibitor package
- Conventional chemistry or traditional inhibitor = A complex combination of inorganic chemicals inhibitor package
- EG = Ethylene Glycol (an antifreeze chemical)
- PG = Propylene Glycol (an antifreeze chemical
- Water Base = Water is the base fluid
- Antifreeze Base or glycol base = EG or PG are the base fluids
WHAT IS COOLANT?
An engine coolant has two main roles:
- Transfer heat from the internal combustion engine to the radiator, where the fluid can be cooled.
- Protect the cooling system materials from corrosion and other damage, including various metals (eg aluminium, copper, steel, solder, cast iron and brass), plastics and elastomers.
Depending on the climate, the engine coolant may also need to protect against freezing temperatures, which is why many coolants contain an anti-freeze ingredient such as ethylene glycol or propylene glycol.
An engine coolant therefore typically comprises a base fluid, which is responsible for transferring the heat (and, if required, protecting against freezing), and an additive package, which is responsible for protecting the system against corrosion and provides other performance advantages.
Given the two requirements of transferring heat and protecting the system, we can classify engine coolants by their base fluid, and by their additive technology package.
Types of coolant base fluid
The type of base fluid will determine the heat transfer properties of the coolant. The base fluid may also alter the freezing point and boiling point of the fluid, which is why you might see the terms “anti-freeze” and “anti-boil” when referring to coolants. In cold climates, the requirement to protect against freezing temperatures is an important one, but those temperatures are not often seen in Australia. In a closed cooling system, most of the protection against boiling temperatures comes from the fact that the system is maintained under pressure (a function performed by the radiator cap), which raises the fluid’s boiling point.
In general, engine coolants can be characterised by the following base fluids:
- Water-Based Coolants (no anti-freeze)
- Anti-Freeze Coolants (typically glycol-based)
Water by itself is the best cooling liquid for the removal of heat from an engine. Like all base fluids however, including glycols, a corrosion inhibitor additive package needs to be added to water in order to prevent corrosion in the system over time.
Where protection against freezing is required, the base fluid will need to contain an anti-freeze agent such as ethylene glycol or propylene glycol which, when added to water, lowers the freezing point of the fluid. There is a trade-off though, as the glycol solution is less effective at transferring heat than pure water. A 50/50 mix of ethylene glycol and water will have a freeze point of around -37°C. Like with plain water, a corrosion inhibitor additive package still needs to be added to the glycol/water mixture in order to prevent corrosion over time.
Read further below to see how pure water compares with ethylene glycol and propylene glycol from a heat transfer perspective.
WATER BASED COOLANT
Water based coolant is a term used to describe an engine coolant that does not contain an antifreeze chemical such as Ethelene Glycol (EG) or Propylene Glycol (PG) but has water as the base fluid. Water makes up to 90% to 95% of the overall fluid of water based coolants with remainder being inhibitor package with it’s concentration depending on the inhibitor grade, type and intended application.
In temperate climates where freeze protection isn’t required water based coolants offer many advantages over their antifreeze based counter parts.
- Water based coolants offer superior heat transfer properties
- eliminate the fire hazard associated with EG and PG chemicals,
- cheaper in purchase cost,
- less friction on internal components
- less disposal costs and reduced coolant handling hazards
Water based coolants are now OE approved by some major manufacturers with PrixMax’s legacy product RCP formally approved by Detroit MTU and Mercedes Daimler.
Waterless Coolants are generally 90% to 95% antifreeze EG or PG with the with remainder being inhibitor package with it’s concentration depending on the inhibitor grade, type and intended application.
Water based coolants are a very poor performing coolant with regards to cooling capacity because of the elimination of water all together. While it can be claimed that this reduces corrosion attacks it is far more beneficial to choose a high quality inhibitor package mixed with water to take advantage of the superior heat transfer properties of water.
ANTIFREEZE ANTI BOIL COOLANT
Antifreeze Anti boil coolant is a term used to describe an engine coolant that contains an Antifreeze chemical such as EG or PG as the base fluid. The Antifreeze chemical generally makes up to 50% to 33% of the overall concentration of antifreeze based coolant with remainder inhibitor package 5% to 10% depending on the inhibitor grade, type and intended application and the remainder water.
Antifreeze based coolants are a necessity in climates that experience freezing conditions. Many OE and OEMS prescribe the use of antifreeze based coolants in their engines and despite some OE and OEMs approving the use of water based coolants nearly all will factory fill with antifreeze based coolant as it may not be known if the engine will exposed to freezing conditions. If operating in a temperate climate maximum performance can be achieved by changing to water based equivalent
THE EFFECTS OF ANTIFREEZE WHEN ADDED TO WATER
Both EG and PG have their own set of chemical properties and when you add them to water, and depending on the concentration you add them, you impart those chemical properties onto water. This changes how water as a base fluid behaves.
EG and PG Effect Waters Fluidity
The viscosity of water is much lower than EG and PG, with EG being around 20 times more viscous and PG around 60 times more viscous than water. This means increasing the viscosity of the cooling fluid directly increases power consumption by affecting pump horsepower and fluid flow. Water based coolants are able to flow more quickly around the cooling system and transfer heat away faster. The table to the left displays the various viscosity properties of water, EG and PG.
EG and PG have poor thermal conductivity
The thermal conductivity of a fluid refers to its capacity for heat transfer. In a temperature rage of 0oC to 100oC, a 50% volume EG based coolant (as found in a typical anti-freeze coolant) is anywhere between 25 to 49% less efficient at transferring heat than a water based coolant. Furthermore Water becomes more efficient at removing heat the hotter is gets where as an EG coolant becomes worse, as seen in table on the right.
Antifreeze has Poor Heat Absorption
Water has a higher specific heat capacity than EG and PG which means water can absorb energy much more readily and thereby more effectively remove heat. Please see the table on the left.
Why Antifreeze (Glycol) Free? It doesn’t freeze in most of Australia!
Antifreeze does NOTHING to inhibit corrosion or lubricate seals in engines, that is the role of the inhibitor package. The only benefits that it brings to coolants are it’s anti-freeze and anti-boil properties and is an unnecessary chemical in most Australian operating conditions.
Antifreeze Is a Fire Hazard
EG and PG are both class 1 combustibles. Brisbane Transit bus service recently changed over to water based PrixMax RCP coolant because of a spate of bus fires. The fires were reported in the courier mail in 2013. Click HERE to read The Courier Mail report.
After a lengthy investigation was found to be EG based engine coolants spraying from a ruptured radiator hose onto an ignition source such as a hot turbo or manifold.
Antifreeze is Extremely Expensive
Both EG and PG are extremely expensive chemicals and by removing them in a situation where they are not needed removes the cost thus allowing for a much cheaper product.
What About Boil Point Protection?
A regularly cited reason for using an aqueous glycol formulation for engine coolants rather than formulated water is the fact that aqueous glycol solutions have an elevated boiling point relative to water. However, while a glycol based coolant does contribute to an elevated boiling point (the boiling point of a 50% by volume glycol based coolant is around 8oC greater than pure water), the mian increase comes from having a system operating under a higher pressure than atmospheric pressure. Even putting aside the superior heat exchange benefits of water based engine coolants (which would effectively negate the higher boiling point of a glycol based fluid because engines run cooler to begin with), the 121oC boiling point of water in a pressurised system remains higher than the normal operating temperatures of most engines (which is typically between 82oC and 105oC). It is important, then, to ensure that the engine is equipped with a properly functioning radiator pressure cap to increase the boiling point of the cooling fluid (and also increase the efficiency of the water pump).
The much more important value in the cooling system than the fluid’s boil point is its ability to carry heat energy out of the engine to the radiator. As can be seen above pure water has a much higher specific heat capacity than both EG and PG, and is one of the most effective coolants that could possible be used. When mixed with an inhibitor such as RCP Platinum water provides the ultimate in cooling system performance
Of course if operating in an environment that freezes the only choice is to use and antifreeze based coolant. But, if operating in a temperate environment like most of Australia it is far more beneficial to use a waterbased coolant.
The effects of bad coolant
What you see here is the difference between good and bad coolanthead to the coolant shop to purchase
COOLANT CORROSION INHIBITOR TECHNOLOGY
A corrosion inhibitor package or additive is the type of additive used to stop corrosion. Generally speaking there are three main types of coolant technology, Conventional Chemistry, Hybrid and Organic. Hybrid and Organic are the most common type available today and can be found as factory
fill in almost all new engines. Conventional chemistry coolants are still available in the market today but are slowly being phased out or replaced with hybrid and organic as they offer much better protection and for longer periods of time as well as numerous other advantages.
TRADITIONAL OR CONVENTIONAL CHEMISTRY BASED INHIBITOR
Traditional (or conventional) coolants are formulated with mineral (inorganic) inhibitors such as phosphates, silicates, borates, nitrite and other components. Different conventional coolants will contain different combinations of these inorganic inhibitors to provide the corrosion protection required. These inhibitors have relatively short service lives so require more regular monitoring and change-out.
Hybrid technology coolants utilise a combination of mineral inhibitors and organic additive technology (OAT) inhibitors to protect against corrosion. The combination of inhibitor technologies is broadly driven by regional preferences. For example, Japanese and Korean OEMs prefer the use of phosphates over silicates, whereas European OEMs prefer silicates over phosphates.
Organic additive technology (OAT) coolants contain only “organic” inhibitors that are virtually non-depleting when compared to traditional inhibitors. Coolants based on OAT inhibitors offer extended life corrosion protection and benefits from a compatibility perspective. OAT inhibitors work by creating a thin molecular layer at the corrosion sites, and – unlike traditional inhibitors – are not chemically consumed as they perform the function of preventing corrosion.
The removal of Glycol from a cooling system has a number of advantages including:
- The removal of a toxic product from site which addresses environmental, OH&S, storage and disposal issues associated with the Glycol.
- The removal from site of a potential fire hazard. Glycol is not as efficient at transmitting heat from an engine to the atmosphere as is a water based fluid.
- The anti-freeze properties of Glycol may be immediately disregarded in our the majority of our climate.
- The anti-boil properties are negated by the greater thermal efficiency of water based products.
- A water based coolant can keep an engine up to 20 degrees C cooler than a glycol based coolant, essential in our extreme summers.
- Glycol is specified as a normal component of a coolant as all major engine manufacturers are Northern Hemisphere based where severe winters dictate the use of anti-freeze, the tropical market is a small percentage of the world market so no reference is normally made, though some are now doing so such as Detroit in their 7SE-298 spec.
- Glycol does nothing to protect the components in an engine, that is the role of the inhibitor in the coolant. It is only added to coolant to lower the freeze point of the water it is mixed with.