RWG wrote
I'm not sure about gas in the UK, but here in Canada and the US, the ethanol gas has ruined a bunch of plastic gas tanks at least. My buddy had a 2012(??)KTM RC8 and we removed the tank to do some work and we couldn't get the bolts to line up to reinstall it. The tank basically stretched after we took it off.
There are a few gas companies here that sell non-ethanol gas (usually Super' grade) so I try to only run that fuel in all my bikes.