Team-BHP - Engine coolant - water ratio | Effect on engine temperature

To keep it short and precise:

Does various concentrations (coolant liquid: distilled water) of coolant affect the normal operating temperature of engine?
eg: a) you buy a 1L coolant concentrate and use 2L distilled water to obtain 3ltr of engine coolant (1:2 ratio).
b) you use 2L of coolant concentrate and use 1L of distilled water (2:1 ratio).
In above case will there be any difference in engine temperatures assuming normal street usage?

Now for the explanation and discussion part:

The reasons why I asked this and what I do in this regard:

I got the coolant changed with a different brand and earlier there used to some other brand workshop guy filled in (this time I bought it from a trusted shop outside and handed over it). Previously my engine temp needle used to stand exactly at 1/4th of the temp gauge under normal operations (city + highway runs). Now, with new coolant it stays a little above quarter mark but much lower than half mark, but it really stays there only.

According to my knowledge- the thermostat regulates the coolant flow such that engine temperatures are always at optimal level (again under normal usage-not hill climbing). It maintains such a temperature where engine performs its best. So, anything above that will be absorbed by allowing flow of coolant.

Hence, varying concentration /brands should not affect much-given that heat absorption rate of mixture may vary but the final temperatures would remain the same right?

Also some related questions to discuss:

1.) given that water is the best absorbent of heat and antifreeze mixture is just to lower freezing point and delay boiling point- it is better to keep water proportions higher than antifreeze- hence I think a 1:2 ratio is better than 2:1 ratio? Also, no matter how much quality (premium) coolant liquid you use- the final engine operation temperature should be the same (after a cold start at least) because if the coolant is of great quality all that it can do is to absorb heat and then cool quickly but still the thermostat maintains optimum temperature only- it is not like you get a 'cool' engine by using a superb coolant, right?

2.) what chemicals are used in the coolants we purchase in market? Of course am referring to those concentrated solutions and not pre-mixed ones available in petrol bunks. Also, why is coolant always in green colour only?? Is it just because of some colour coding or the chemical composition itself?

Earlier I used to wonder whether the temperature needle could be brought to coolest side by using special coolants so that car will run 'cool' stupid: Now I know a steady optimum temperature is what an engine needs to perform.

Quote:

Originally Posted by nitroxx (Post 714799)

You ended up answering your own question...congratulations!! on self diagnosis...

hey jokes apart why don't you share your experience,besides my last question of what the commercial coolants are composed of is atleast unaswered. you can give it a try i think
EDIT:

Quote:

I top up with coolant / water just by an informal "colour" check.

i personally believe keeping water ratio more the coolant liquid ratio will help in better heat absorbtion and hence lesser over heating than using concentrated mixtures of coolant liquid and water. Ofcourse, most people avoid this headache by purchasing pre-mixed coolants like that we get in petrol outlets.
:)

Quote:

Originally Posted by nitroxx (Post 714799)

You ended up answering your own question...congratulations!! on self diagnosis...

lol:

deetee, I tried to read your post but its a pain. Do try to make your posts more legible. :)

And about color
http://www.tegger.com/hondafaq/overh...e_Mag_53_g.pdf

True Colors

"the original glycol-based “green” antifreeze we are all familiar with. They have quick-acting silicate and phosphate corrosion inhibitors that do a good job inhibiting corrosion on both iron and aluminum surfaces. This familiar green liquid has proven its worth in all the temperature extremes of North America. Virtually any vehicle can use this fluid."

Quote:

Originally Posted by kushagra452 (Post 5332075)

The primary heat transfer medium in the engine is water which is then routed to the radiator to lose heat via heat transfer to air.

Coolant is only there for corrosion resistance, boiling point and freezing point enhancements and in some cases water pump lubrication.

I would strongly recommend using the recommended dilution ratio for water:coolant in the correct ratio. 50:50 is the standard. Please check your car owners manual. Change water:coolant ratios only if the manufacturer specifies it.

To remedy what you have done just drain our some coolant from your radiator and add either distiiled or filtered drinking water to top it off to recommended levels.

Quote:

Originally Posted by kushagra452 (Post 5332075)

I drive a Swift VXi AMT and recently I topped up the coolant + water mixture with just the concentrate. I believe the ratio would now be 85:15 (concentrate:water).

Will such a high level of concentrate be bad for the engine?

The car is presently running in Delhi NCR - which is experiencing a severe heat wave (45 degrees Celsius+ temperatures).

Thanks!

I know a mechanic who recommends driving only on the coolant. He had done 100s of engine and radiator overhauls and says that pure coolant protects the engine better than water plus coolant. I know the science behind coolant water mixtures and will not follow this advice. But as you have mistakenly increased the coolant ratio, I will suggest let it run like that or pour water in the tank when the engine is cool to dilute it further.
There is no need for replacement, relax.

As mentioned by others, a different ratio should not have an effect on the temperature. In theory there is going to a difference between the water and the coolant in terms of how well they can absorb heat. But your thermostat will compensate for that and the difference is likely to be small anyway.

But far more importantly as other members have pointed out: your coolant also has a number of additives that ensure proper corrosion resistance and prevent sludge forming. Too much water gives you a too much diluted coolant solution. It will cool just fine. But offers very little protection against corrosion and sludge building up in the cooling system.

Always check with your owners manual and stick to its recommendation religiously! Don’t believe the Internet. Stick with what your manufacturer recommends.

I am not sure in India, but in general there are different type of coolants. Mainly depending on the engine materials. In Europe most people will be using pre mix and it comes in two colours, pink or blue. You should not mix the two and you should not use blue if your owner manual says pink or vice versa.

Jeroen