So the price difference is nothing to do with supermarket garages, being able to spread the cost where as the independant retailer cannot
Or they use the same oil refineries and delivery trucks
I have seen a delivery truck go to Safeway then go across the roundabout and do a delivery to a BP Garage.
I dare say BP Ultimate and Optimax are probably branded individually but the rest is probably all the same.
This not new the UK is just catching up, I used to work in Germany and every petrol station used to have 3 levels of Unleaded.
93 Ron, 95 Ron & 97 Ron and depending what you were goint to do if it was tootle round town then you could use 93, for long motorway journey's 97 Ron, gave you better performance and mileage. This was about 10 years ago as well.