ethanol sucks in water you have high performance engine why would you want to use low quality fuel                                                                                                                                                                             

Cos I'm on a carb bike I use E5. Tried E10 and after lay up it run like crap. Since switching to E5 it's much better. Plus with the E5 occasionally I add redex to treat the fuel which as improved my performance.                                                                                                                                                                             

Speak to any HGV fuel tanker driver and they will tell you that Esso is the only company which puts every single additive in their fuel at the refinery prior to delivery to a forecourt. Tesco Express petrol stations use Esso fuels.                                                                                                                                                                             

I suggest checking out some YouTube videos on the topic. Especially ones catered towards motorbikes.
Personally, I always used E5 on my carbed bike but use anything on my current FI bike.                                                                                                                                                                             

E10 with the extra 5% ethanol is just bad for engines not made for it, damage will happen over time in certain conditions. Carbs with the rubber may go in time and possible blockages in the tiny channels and jets. If your owners manual, bike states it does does not meet the rating then best not to stick it in. As for MPG as there is less fuel in the mix, yes you are going to get less mileage. Carbs require more care anyway as we know, so a change of the rules, the way you do things may be all you need. See the video below for some good possible advice.

https://youtu.be/NYNs0ZtwZeo

After contacting Esso/Ultron last August I have finally, after multiple emails, got an answer about their E5 fuels which is as follows;

'Esso Synergy Supreme+ petrol has up to 5% ethanol in North of England, North Wales, Scotland, Devon and Cornwall.

In other areas of the UK, Esso Synergy Supreme+ petrol may be ethanol free at Esso branded petrol filling stations that are normally supplied directly from an Esso terminal. No guarantee is made that Esso Synergy Supreme+ petrol sold at these sites will be ethanol free at all times.'

So all you have to do is know whether your local filling station is supplied directly from an Esso Terminal and cross your fingers...that is unless you live in the above mentioned areas that definitely have 5% ethanol although you can at least enjoy the scenery as you fill up!

What's interesting here is that there is a thread similar to this on a BMW K1600 forum, but the main part of the thread was around the grade of the fuel and the RON/octane rating with the effect low-grade fuel has on engine knocking, performance and MPG and it is far less focused on the ethanol side of the issue.