I'm sure fuel is a heated topic around here, but a conversation with a friend has me wondering a few things. Around here (south central Minnesota), the highest octane we have available is 91. Our options are Speedway (lol nope), Kwik Trip, and Holiday. No Shell, no BP, no Chevron, etc. Speedway is out for many, many reasons. Kwik Trip's 91 is sold as "recreational fuel only" in Minnesota (high performance vehicle fuel in Iowa and Wisconsin) and contains no ethanol. Holiday's 91 does have ethanol. Both fuels are Top Tier.
He was told to stop using Kwik Trip's fuel after his engine ran rough using it and has since switched to Holiday's fuel with no issues. He was told the lack of ethanol was a contributing factor. Does ethanol really make that much of a difference?