//The names relate to the percentage of ethanol and biofuel present in petrol and diesel respectively, and are intended to make motorists “think more carefully about the environmental impacts of their journeys” and “educate drivers on the benefits of biofuels.”//
Good luck with that then (to whatever clown thought it up). Let's get this right - you pull up at a fuel station, see the label "B7" (or whatever nonsense is displayed) and then begin to "think carefully about the environmental impact of your journey." You decide that B7 is not good enough and that you really want B6 (or B8?) so decide against filling up. Instead you set off on a detour of 20 or 30 miles to get the gas you need. What a load of cobblers. If you were worried about the environmental impact of your journey you'd have made other arrangements. Another load of nonsense that will make precisely zero difference to the "problem." But it looks good on paper.