What about ethanol? I've heard that Shell V-Power (91) doesn't have any.
Most 91 octane gasolines don't contain ethanol. You don't want to be filling your marine, sled, ATV motor, chain saw with ethanol gas if it can be avoided or a 20 year old car/motorcycle.
In the USA, land of few rules, some mid western retailers have been adding up to 18% ethanol and not disclosing it. I'm thinking 15% might be happening up here on occasion.
If available I buy from the newest station, with the newest tanks and pumps. I favour Sunoco and UPI.