Quote:
Originally Posted by rx3
The most effective coolant would be pure water without any antifreeze (assuming temperatures don't fall below 0 C). As water has a higher heat capacity and a lower viscosity than propylene glycol or ethylene glycol: http://www.engineeringtoolbox.com/pr...col-d_363.html |
What does viscosity have to do with coolant properties? Water vapor has extremely low viscosity, but it is a horrible coolant.
Also, did you notice how the boiling point goes up as you have an increase in the percent propylene glycol in solution? This is a good point for a coolant system. It is known as a colligative property. Water vapor has an extremely poor heat capacity compared to a 50% solution of liquid water and glycol.
You may be thinking "race cars run water, so it must be better". This is because the tracks don't want to clean up the environment every time a car pops a radiator. If there is only water in the cooling system, there is no clean up required.