From Shell themselves in the link above( jura 11 post)

which basically means they do.

 

Yes I read the link, but it doesn't actually give an amount. Up to 5% could mean they use 0.1% ethanol compared to Tesco who could use the full 5%.
They won't give away what additives or the amounts they use because the additive package each company uses is their own mix.

 

I use OMV 100 RON and PETROL 100 RON out in Croatia and pay less than £1.20 per litre at the min. car seems to run slightly smoother on the PETROL 100 RON than on the OMV stuff, When in the UK recently I was using Shell as normal and noticed some hesitation in traffic, few days later I switched to Momentum as I sometimes do, the hesitation disappeared. Make of that what you will.

I don't know how people manage to run low on fuel I never let mine go below a quarter of a tank, even if it's on 3 quarters i'll still fill it up when I come to a station with suitable fuel.