Originally Posted by TimRogers
It's a question of getting the fuel to vaporize better. It might help in colder weather, not so much in hot weather.
Now that I can read the first site posted that site has nothing to do with fuel vaporization. That article seems to be trying to keep the fuel line cool so that it doesn't cause vapor lock with boiling fuel in a hot engine compartment, and doesn't talk about heating the fuel at all. Unless there is a vapor lock problem there is no benefit or improved vaporization.
Preheating the entire engine has some benefit but warm gas alone, not so much.