As I'm currently in the UK myself - do people experience big differences in mpg between supermarket (e.g. Tesco) regular Diesel and "brand" Diesel (BP/Shell etc.)? As price difference seems to be nonexistant now (saw Tesco 1,98 vs. BP 1,99 today) is there any reason to go for supermarket?#
(Do prices not change hourly throughout the day like they do in Germany?)
Coming up from Germany with Star/Orlen Diesel and going 56 to 62 mph in my TDI90, I managed 74mpg up to Durham with a bunch of stops, sleepovers and jams, while on the Tesco fuel taken on there, I've been struggling to get 63 mpg (a difference of 0,7l/100km or 20%) while barely doing 50mph half the time and otherwise going as economically as possible.