Knowing that my local Esso had E5* pumps I filled the BX up with that, but the cost! £7.55 per gallon or £1.659 per litre which is by far and away the most expensive petrol I've ever put in a car. I will be interested to see how well it goes

Obviously I need to research more keenly priced petrol, but can any one recommend any good websites/apps listing garages with E5 petrol and prices?
*According to Esso there is in certain areas of the UK there is actually no ethanol in their E5 petrol.