Which electronics give best fuel economy

[amcpacer]

If I were to build a 2.2 turbo engine for maximum fuel economy while retaining OEM power levels what kind of system would be best. Stock calibration, modified stock cal from dcal or chem, or megasquirt? This is for my 85 T1 draw-through laser.

What kind of fuel milage is everyone getting with their setup?

I am wondering if a lean burn style calibration could be made that would work in conjunction with a water injection to cool combustion and supress detonation. Maybe run 14.7:1 even while in boost?

On my previous car with 87 electronics I used moparchem to try running the fuel mix leaner while the engine was under light load but it made the engine output feel shaky and backfire sometimes. Perhaps it would be possible to disable the O2 feedback to force the engine to run a constant fuel mix instead of running rich then lean then rich again.