I use Esso E5 which in fact E0.
It's pricey though. If not I'll use E10 muck with Millers anti ethanol treatment.
Not for long they are adding ethonal to it from September, it'll be E5.
This is a post from a gent from another car forum -
Even E5 gives problems particularly if you store the vehicle for a while... If you do, make sure you drain it all out particularly on cars and bikes with steel tanks.
I am seeing more and more bikes with rotted out tanks where they have been sored for even 12 months. it seems that you get an acidic condensate come off it that rots the top of the tank!
I had this one in recently that had been off the road for 2 years with half a tank of E5 fuel. The guy said he first noticed the paint was bubbling... then realised it was rust from the inside!
I had it sand blasted... you can see the extent of the pin holes from the light I put inside.
I know most newer cars dont have steel tanks, but you dont really need any more of this stuff than is neccessary