I was driving my 2017 1.4 Octavia back from France over the weekend and foolishly put 40 litres of E85 bioethanol to top up my tank of SP95 petrol. So 40 litres of bioethanol and 10 litres of normal petrol. I realised my error immediately and got concerned that the Octavia would run badly. However it ran completely fine. I topped it up with some SP98 after a few miles, then put another 20 litres of SP98 in after a couple of hours. It got home no problems at all - I didn't notice any change whatsoever in performance, apart from worse fuel economy. When I looked at the handbook it said that it could run on SP91 but with worse performance rather than the recommended SP95. Next time I am in France should I go 50/50 petrol/bioethanol? Bioethanol is only 1 Euro a litre on the motorway service stations...