The fuel isn't changed at the refinery it is only after it has been refined are additives added. E.g. shell vpower, bp ultimate and the like. Standard 95 ron petrol all comes from the same distribution depot.
My farther work at a bp distribution depot and as well as bp tankers picking up the fuel you get supermarket ones to. On the same industrial estate Esso, Texaco and shell have supply depots and guess what you get supermarket tankers using all of them. Supermarkets buy from whoever is cheapest at the time and they also use the sale of fuel as a loss leader to draw customers, the same as they sell alcohol at a loss.
This is why supermarkets are normally slightly cheaper than other petrol stations. Standard 95 Ron petrol is exactly the same no matter where you buy it from the only company i know of is shell at have started using additives in their normal fuel to.
The rumour that supermarket fuel is bad for your engine has been going around for years and has been spread by a mixture of ignorance and sheer blind faith that it is write and there is absolutely no evidence at all that it will do any harm to your car.
If you are prepared to pay the extra 7 p a litre then you can go for the shell v power and the like this is simply an additive added at the depot.
Finally why would the supermarkets risk being sued by thousands of people by selling inferior fuels as well as the damage to their reputation for the sake of selling fuel a few pence cheaper than there competitor ? The fact is they wouldn’t, the myth is a complete load of ******** all fuel sold in this country has to abide by strict rules and standards.
