If that was actually true Trading Standards would go livid. Anyway the tanker driver is talking shit. There is only one main distribution site in Scotland, Grangemouth, and fuel companies use each others tankers especially to outlying areas. Tesco don't make fuel and only buy on the open markets. Their 99 is the minimum spec they they use and basically it is EU imported into SE England Thames storage facilities. They also buy from Shell and BP and in fact some of the 99 sold by TESCO outwith main population areas is really SHELL / BP. What you bought was genuine Shell V-Power sold to Tesco at market rates from Scottish distribution.