I believe there are only 6 refineries in the UK so when you buy Esso or Tesco or BP in an area its likely all to come from the same refinery. Presumably the additives vary from brand to brand though I would be surprised if the supermarkets had the staff with technical skill to decide such issues. Much more likely is that Tesco is own brand version of say BP or Shell.
As for alcohol, I dont understand the issue. Ethanol has a higher octane rating than gasoline ( 109) so the timing should retard a bit with a mix of the two and the exhaust run a bit cooler. Maybe thats why Peters EML comes on - but I am speculating way beyond my knowledge here.
I always filled the Fezza with the cheapest 95 octane I could get and no issue. Mind you at 16mpg average I had to go cheap.
Last edited by howard; 17/04/19 07:02 AM.
