[drmilsurp]

I think the theme is really power on demand. I don't like the idea of an electric turbo/compressor for the same reasons I don't like quartz watches. But maybe adding an electric compressor and upgrading the already taxed alternator will offset the parasitic loss?.

Performance and economy are in opposition. It is still all down to Air/Fuel/Spark. You just know that 10% was from DI and fuel cut on the odd cylinder in spite of the eturbo. When you open the throttle plate 100% and get that turbo of any kind running 100K+ rpms, ignition advance drops, fuel flow jumps and there goes your fuel economy. Again, you cut the fuel when you don't need it and/or stop spraying fuel everywhere else but directly in the chamber. Where you fall on the curve before/after MBT can be changed but it's not really possible to run after (lean side) the fuel curve with standard fuel stocks and certainly not under boost, ie you can do it, but you won't be making any power.