Dry Ice.

[SSDiv6]

Originally Posted by Larry Hill

I thought it takes heat to help atomized the fuel so the smaller particles will burn more completely. Will cooling the fuel slow the process and result in larger particles in the cylinder. Is it less important in a FI than a carbed engine.

Increased fuel temperature makes the fuel less dense and reduces the amount of oxygen, many times turning it into vapor. Cooling the fuel, increases its density and the oxygen molecules stay closer when compared to hot fuel and reduces vaporization. It also reduces the vaporization rate of the fuel. That is why warm or hot fuel causes vapor lock.