Just curious, but where did you hear that? The only times I've ever heard of people switching to pump was because they didn't want to deal with moisture collecting in the tank during storage.Braver than me. E85 is to volitale. If mines sitting I load the pump gas tune and put 92 in it. But this year It didn't sit for more than a few weeks.
I ran a quick search that says otherwise. Whether or not it's right I don't know. Thankfully I don't have to store my car.
Alternative Fuels Data Center: Ethanol Vehicle Emissions