What properties make gasoline a good coolant?
The term coolant refers to a substance that helps draw heat away from an object. A coolant needs to have a high thermal capacity so that it can absorb a large quantity of heat with a small increase in temperature. It would also need to have a high ignition temperature so that it does not catch fire with a small increase in temperature. Good coolants are also non toxic, chemically inert, and do not cause damage to what is being cooled by corrosion.
Gasoline has an ignition temperature of approximately 280 C, the specific heat of gasoline is 2.2 kJ/kg K and a freezing point of -40 to -50 C. It starts to vaporize at 70 C and the final boiling temperature is 210 C.
It is not very clear why gasoline would be a good coolant with the properties that have been mentioned. At temperatures below 100 C, water is a great coolant and by the time the temperature reaches 100 C around 70% of gasoline would have evaporated.