Discussion: Let's talk coolant

Redglare

ideally you want to increase the specific heat (c) of the solution to have the best coolant possible, however ethylene glycol has a reduced specific heat, so you want to mix it with water to increase the specific heat.

also have to consider that branching lowers the BP, hence why ethylene glycol is also picked over other alternatives.

also fun fact, even though ethylene glycol doesn't have the double bond between the vicinal OH's, the name retains ethylene because it was derived from an alkene.