Interesting to know you all so well quip with coolant information... here is some additional to clarify the facts and myth
1. why do we use coolant + water for the radiator?
To balance off the property of both, related to
heat dissipation ability and also
temperature.
Temperature
In cold country, winter can reach -20C .. -40C
Coolant in most form is made from ehtylene glycol, a liquid that will freeze at -13C, trust me a lot of the part in the world, the winter is more harsh. Here come where water will play the part, water will freeze at 0C , however, combining these two liquid it will allow the freezing point drop further more. (long lecture on crystallization...)
Summary
Water 70%-Cool 30% Freeze @ -7C
Water 50%-Cool 50% Freeze @ -34C
Water 30%-Cool 70% Freeze @ -51C
Water 10%-Cool 90% Freeze @ -29C
That is why you need water.
Heat Dissipation
In our hot weather country, forget about the winter, is hot we need to throw it out!
Fact: Coolant got only 50% of what water can hold.
Myth: Coolant to improve cooling efficiency, but is not. In fact, it increase the boiling point as a cooling agent
Coolant is not only cooling agent, its a lubrication, protector, prevent calcification and protect your radiator from over blown! How ? By raising the temperature up !
Coolant has a very great boiling point, which is roughly 200C, which sound not practical but is helpful. because water boiled at 100C, everytime the water is circulated in the block, the temperature of water increase very fast and instant, there will be alot of times the water will raise near or above where the water vaporized, when it vaporized, air expand ( read back ideal gas law..)
then Pressure build up and then your radiator take the hit. If your car cooling is aged, most likely it will burst the radiator at it seam.
Adding Coolant into it, will does the little magic trick, by increase the boiling point up above 100C, at 70-30 you will get about 132, which is very safe from vaporize point in your cooling system.
2. can i use only coolant, no water?
heat dissipation will be 50% slower, and the coolant temp now can go high up 200C before it will build up pressure where your cap fail safe mostly at 0.9~1.1bar. Your cooling system will start failing eventually
3. will my cooling system bacomes better n my engine temperature go down more if i use 100% coolant?
Definitely NO.
4.
is it true if we use 100% coolant the radiator tends to crack at the joints n become weaker and prone to clogging? (heard this from few reputable pomen......) true, but no the clogging because there will be leak not clogs .. hahaa....
Additional
The main harm from gov water source, is chlorine (which use to kill germs) and chalk (batu kapur) (use to clean water)
Mineral too contains unknown pollutant source.
So the best one is to get Distilled water
Ethylene glycol is little acidic or neutral in general. However the interaction long time with heat and water in the system, after sometime it will turn acidic. So always check the PH to make sure it is not hurting your cooling system.
Using only distil water in your cooling system is good enough, but you should be aware of the vaporization process, rusting and calcification. How and where it come ? Do you think your water pump is made from aluminum ? Stainless Steel? or Copper?
most market sold coolant is pre diluted, mainly Water70-Coolant30 (for trusted brand).
As guide. Japanese vehicle should not use more than 15-30% of coolant, European never more than 30-50%. Best guide, follow manual book.
