[KingLT1]

As mention above, speaking in terms of Lambda for E85, Stoich is 1.0. WOT PE should be around .87 for a NA application. You would still target the same fueling even on E60. The Flex tune will adjust the stoich ratio and Stoich will remain 1.0 Lambda on your Wideband.

If you want to speak in terms of AFR then Stoich is around 14.1 for E10 93 and WOT PE I believe GM normally target's 12.6 which is a tad rich.

Ethanol allows the ability to run a little leaner due to being superior at cooling the combustion process and pulling heat out of the cylinder.

You never target 11.5 on a DI engine even with boost. DI stuff does not like running that rich.