engine coolant
 

is there a negative effect (aside from cost) to adding just antifreeze to the coolant system instead of a antifreeze/water mix?

Regular antifreeze by itself doesnt cool as well as water.

Antifreeze/coolant doesn't dissipate heat has quickly as water. However, it does have a higher boiling point than water as well as providing anti-corrosive protection.

So, the idea is to get the best of both worlds by mixing them to get the best overall cooling (better heat dissipation from water, with raised boiling point and anti-corrosive protection from antifreeze).

I wonder what the BEST heat-transferring liquid that could be used is? I'm talking cost-is-no-object type of stuff. Surely there is something used in industrial heat exchangers that far exceeds standard ethylene-glycol based coolants.......?

Chemistry guys chime in......

Mountain Dew... it looks like super coolant :D

Pure water. The absolute best for conducting heat away is liquid lithium (I think it was lithium). You wouldn't want to try that in a car, though ;) . It's been used in miniature nuclear power supplies.