there would be the down fall of using premium gas? its just adding a varible resistor
it gives small gains but enough
remember more is always better
its really funny that no not many people know about it if you went to the teamzx2 forum that'd be the first thing they'd say. all the resistor does is fool the computer into thinking the air is colder and therefore more dense, more dense means more air per cubic foot requiring more fuel, so the computer tells the injectors to put more fuel though richening your mixture, it like jetting a carb
heres a link to how to do it
pots mod it works pretty good. the difference between this mod and jsut adding a resistor is that its varible, and it can be turned off.