I stopped by a local Conoco gas station today I do not normally frequent. While pumping some regular 'ole cheap gas into the Tacoma, I noticed that they have their premium gasoline advertised as ethanol free. I know that the TW is designed to run on 87 octane. So I got to wondering if I should still be running regular gas with ethanol treatment, or switch to my new found and closely located source of ethanol-free 91 octane. Thoughts?