[cleanspeed1]

The thing that needs to be investigated is heating the fuel up sufficiently so that the step from tank temp to combustion temp is not so hard. The hydrocarbon chain has so many boiling and cracking points that reactivity is not complete, hence the lower than best mpg. Combine that with better atomization, who knows what could happen.
Just looking at the spray patterns of the IDI injectors, it leaves a lot to be desired.

If it wasn't for the fact that the pump and injectors can't be operated at high temperatures, I'd love to do a DB2 and test it out.