Isn't "Anti-freeze" an amazing product. We have you guys up there adding it to prevent freezing and us lot down here adding the same product to raise the boiling point of the coolant to prevent boiling. Can't think of any other products that improve both ends of the spectrum and also assists in corrosion protection as a bonus.
Strange colours you mention, ours is green for older motors and red for the newer. Check the label on the container or the company website for best concentrations to run. I use an Australian made Nulon Long Life Coolant, which advises the temperature changes at different concentrations on the container. I just checked the label which is as follows
Standard Conditions Using Coolant + Demineralised Water (33%) Boiling point 127 deg C Freezing point -18 deg C
Extreme Conditions Using Coolant + Demineralised Water (50%) Boiling point 132 deg C Freezing point -37 deg C
I remember seeing a data sheet many years ago showing higher concentrations of coolant (might have been 67%) with the boil point going up to to 141 deg C, but the Freezing point was worse than 33% & 50% concentrations. I ran that higher level in my rally car. Freezing wasn't something we ever had to worry about and you could drive as hard as possible in the heat of summer with the Temperature gauge occasionally well into the red and not have to worry.
Also worth considering if you haven't already got one is an expansion tank/bottle as this will keep the radiator full as the expanded coolant is captured in the bottle as the motor heats up and draws it back into the radiator as it cools. If you do add the expansion bottle remember to get a replacement radiator cap intended for use with an expansion bottle.
Cheers Stephen
