At first glance, two of the claims made for AMSOIL DOMINATOR Coolant Boost seem to contradict each other: it can help an engine warm up faster while also helping it run cooler.
The explanation is not that Coolant Boost somehow makes coolant inherently hotter or colder. It changes how effectively heat is transferred between the engine, the coolant and the cooling system.
DOMINATOR Coolant Boost uses surfactant technology to improve contact between the coolant and metal surfaces. Better contact allows heat to move more effectively into and out of the coolant.
What Does a Coolant Additive Actually Do?
An engine cooling system is constantly moving heat. Combustion and friction generate heat within the engine, that heat passes through metal components into the coolant, and the coolant carries it to the radiator where it can be transferred to the surrounding air.
The effectiveness of that process depends on more than simply how quickly coolant circulates. The coolant also needs effective contact with the hot metal surfaces from which it is trying to absorb heat.
This is where surfactants come into the picture.
Surface Tension and Heat Transfer
Water molecules are strongly attracted to one another. This creates surface tension - the same property that causes water to form beads on some surfaces rather than spreading evenly across them.
A surfactant reduces that surface tension. In a cooling system, reducing surface tension allows the liquid to make more effective contact with the metal surfaces around it.
AMSOIL DOMINATOR Coolant Boost uses three surfactants, each designed to operate over a different temperature range. AMSOIL describes this as tiered-surfactant technology, intended to improve liquid-to-metal contact from initial warm-up through normal and high-temperature operation.
DOMINATOR Coolant Boost uses three surfactants designed to operate across low, medium and high temperature ranges.
How Can an Engine Warm Up Faster and Run Cooler?
This is the interesting part.
When a cold engine starts, combustion begins heating the cylinder heads, block and other components before the entire cooling system reaches operating temperature. Improving heat transfer allows more of that heat to move from the hot engine components into the coolant.
AMSOIL reports that its tiered-surfactant technology helps engines warm up an average of 54% faster. In a road vehicle, that can also mean the heater and demister receive useful heat sooner.
Once the engine is hot, the same improvement in heat transfer continues to work in the other part of the cooling process. Heat moves from the engine into the coolant more effectively, and the cooling system can then reject that heat through the radiator.
So "warms up faster" and "runs cooler" are not opposite mechanisms. Both result from improving the movement of heat through the cooling system.
How Much Can DOMINATOR Coolant Boost Reduce Temperature?
AMSOIL states that DOMINATOR Coolant Boost can reduce engine temperatures by up to 25°F (13.8°C) in straight-water applications.
The words "up to" and "straight-water applications" matter. A coolant additive cannot guarantee that every engine will suddenly operate 13.8°C cooler. The result depends on the coolant mixture, cooling-system design, operating conditions, airflow, ambient temperature and how much thermal capacity the system already has available.
It is designed to improve heat transfer. Any resulting reduction in operating temperature depends on the engine and cooling system in which it is used.
Why Do Racing Engines Sometimes Use Straight Water?
Water is an excellent heat-transfer fluid, which makes straight-water cooling systems attractive in some racing applications. Removing glycol from the mixture can improve heat-transfer performance where freeze protection is unnecessary and competition rules permit straight-water systems.
But plain water also gives up important properties supplied by a properly formulated antifreeze/coolant. In particular, it does not provide the same freeze protection, boiling protection or complete corrosion-control package.
DOMINATOR Coolant Boost is therefore particularly useful in racing applications where straight water is used. In addition to its surfactant chemistry, AMSOIL formulates Coolant Boost to provide corrosion protection for cooling-system metals.
Corrosion Protection Still Matters
A cooling system contains several different metals and alloys. Radiators, engine blocks, cylinder heads, fittings and other components may introduce aluminium, iron, steel, copper, brass and solder into the same system.
Water, heat and dissimilar metals create an environment in which corrosion control becomes important. Corrosion products can damage components and can also interfere with heat transfer if deposits accumulate within coolant passages or the radiator.
AMSOIL reports that DOMINATOR Coolant Boost limited corrosion on six metals commonly found in cooling systems - copper, solder, brass, steel, cast iron and cast aluminium - in industry testing.
Does Coolant Boost Replace Antifreeze?
No. DOMINATOR Coolant Boost is a coolant additive, not a replacement for antifreeze where freeze and boil protection are required.
AMSOIL states that it is safe for use with antifreeze mixtures as well as straight-water racing systems. It is also compatible with distilled, bottled and tap water.
For a normal road vehicle, the starting point should still be the coolant type and concentration specified by the vehicle manufacturer. Coolant Boost can supplement an appropriate cooling-system fluid; it should not be used as a reason to disregard the manufacturer's coolant requirements.
How Much DOMINATOR Coolant Boost Should You Add?
The recommended dosage depends on whether the cooling system is using straight water or an antifreeze mixture.
Add 2 fl. oz. per quart / 60 mL per litre of cooling-system capacity.
Add 1 fl. oz. per quart / 30 mL per litre of cooling-system capacity.
With the engine off and cool, make sure the cooling system is filled with the selected coolant. Shake the bottle, add the calculated amount of DOMINATOR Coolant Boost to the radiator, then start the engine, turn the heater on high and run the engine for approximately 15 minutes.
AMSOIL recommends draining and refilling a straight-water cooling system and adding fresh DOMINATOR Coolant Boost once per year.
Where Does Coolant Boost Make the Most Sense?
DOMINATOR Coolant Boost was developed with high-performance and racing applications firmly in mind. When an engine is operating under sustained high load, the cooling system may be dealing with considerably more heat than it encounters during ordinary driving.
Track cars, competition vehicles, towing applications and other hard-working engines can therefore make heat-transfer efficiency particularly important. Straight-water racing systems are an especially obvious application because they can take advantage of water's heat-transfer characteristics while benefiting from additional surfactant and corrosion-control chemistry.
The same technology can also be used in passenger vehicles with antifreeze mixtures, although the measurable temperature change will vary from one cooling system to another.
A Coolant Additive Can't Fix a Faulty Cooling System
Coolant Boost should not be treated as a repair for an engine that is overheating because something is wrong.
A blocked radiator, failed thermostat, damaged water pump, faulty cooling fan, leaking system, combustion-gas leak or insufficient coolant needs to be diagnosed and repaired. Improving heat transfer cannot compensate for a cooling system that is no longer functioning correctly.
Its job is to help a functioning cooling system transfer heat more effectively.
The Bottom Line
AMSOIL DOMINATOR Coolant Boost works by changing the behaviour of the coolant rather than simply changing its operating temperature. Its three-surfactant system reduces surface tension and improves contact between the coolant and metal surfaces, helping heat move more effectively through the cooling system.
That explains the apparently contradictory result: improved heat transfer can help move heat into the coolant more quickly during warm-up and move heat away from the engine more effectively when the engine is working hard.
For racing applications - particularly those using straight water - the combination of improved heat transfer and added corrosion protection makes the concept especially useful. In road vehicles it can also be used with antifreeze mixtures, while the correct manufacturer-specified coolant remains the foundation of the cooling system.
