Numerous BP and Phillips 66 in eastern Iowa are switching to all ethanol. In Iowa, state inspectors will put a blue background American Ethanol decal over the nozzle in question for ethanol grades, so look closely before buying. Many BP stations in western Illinois still carry high test ethanol-free gas.
Check out pure-gas.org to locate stations nearest you.
We have discussed the ethanol issue with Weissach and PCA technical experts, and they all agree on staying with pure gasoline, most certainly for pre-2000 Porsches.