Always use STD unleaded but avoid the supermarket stuff there's a good article on fuel in one of the monthly mags
That's not what the article says though I will stick to using zero Ethanol fuel whenever possible, and deffo before a winter lay up... Standard unleaded is the worst for Ethanol and Ethanol is the worst for you bike...
I never put supermarket fuel in my bikes. Where do you get zero Ethanol fuel? Don't tell me a bloody supermarket!
Esso: Synergy Supreme Plus - apart from in Devon & Cornwall, Teesside and Scotland for some reason...
Filled up the bike at a BP once. Got about 20 yards and the bike died. Got recovery and it was diesel in my tank. Checked my receipt... unleaded. Recovery guy gave the manager a bollocking. He swiftly shut up shop and ran off, refusing to admit anything. Never did get reimbursed as he obviously had it all put right and just denied everything. Cost me about £200