Surfacant:
Surfactant - Wikipedia, the free encyclopedia
While it's technically not a surfacant, heat energy has a similar effect by lowering surface tension. This improves both atomization and vaporization.
Gasoline is made of a variety of hydrocarbon molecules with a mix of vaporization temps. Some of them do not flash vaporize until the temp reaches around 400*F. The problem is that many of the hydrocarbons will flash vaporize at temps well under 200*F, so that problems like vapor-lock will pop up unless contingency measures are taken against it.
The main point is that some heat does help, especially in situations where atomization or vaporization is poor. This is common with wet-flow induction systems (carburetor & TBI), and in very cold conditions.
A fuel system under high pressure can handle more heat, but don't forget about your fuel vapor recovery system. Heating the fuel can overwhelm the vapor control/recovery, so again contingency measures have to be taken to handle the extra vapor from the tank.
MPFI with the injector spraying on the back of the intake valves will show the least improvement from heating the fuel. That's not to say it doesn't work at all, but every system responds slightly differently, so you'd have to try it out and then decide if it's worth the trouble.