Originally Posted by MotorCityRam
Don't need the tuner to get rid of the MDS on the '09+. Just blip the shifter into ERS 5 mode. You'll get all 5 gears and it never drops into ECO mode.
That's not a reasonable method to bypass the MDS. By blip'n the ERS into 5 mode you effectively disable the 'overdrive'.
I had to try it just to make sure...I disabled MDS with the programmer, then cruised on the freeway at about 60-65 mph, there is about a 500 rpm difference at 60-65 mph when you blip into the ERS 5 mode (vs non ERS 5 mode).
This most certainly will effect your mileage, especially at higher speeds/rpms.