I'm not really sure exactly how some of these aftermarket ECUs work. If I got one could I have two different series of settings or maps or whatever and then have like a switch to change between different driving styles. Have one setting with low boost and lower fuel injection and such to get better gas mileage for daily driving and then another setting with high boost for when I find those twisties.

 

Sure.

Some require a map change which can take several minutes.
Others can be triggered by certain parameters or a remote switch if you like.

BUT...
With MAP sensor based systems, you can have your big power under heavy throttle loads *and* good gas mileage under light throttle.


-Ted