What is the purpose of the "FlexFuel Grand Caravan" ?

I recently saw a Grand Caravan that had a FlexFuel badge on the back. And I was wondering ; What is the purpose of those ?Especially in California where I am, E85 is not that common.I mean, it is great to be able to use both, but why ? via /r/cars http://ift.tt/2uInnln