The only real area I've noticed was if i was using cheaper aftermarket transparent fuel hoses
It seems they only have a life span of about 1.5 years or so.
But I don't know if it's related to the fuel or to the UV damage.
Otherwise on my three airheads running Ca "gas" they are fine, I don't have to step up to 91 on my 60K mile R80, since I think there's come carbon causing a little pre-ignition if I don't.
On vacation for a spell