That's made quite a splash, doubtless as Asda intended :-) But there are many other factors at work, as you know, Dave. This time of the year always sees a glut of fuel, since many factories and businesses are only now starting to return to full operation while the schools are yet to open, so the school run - which sees a 12-fold increase in traffic during the morning and afternoons on roads locally - hasn't yet started and, of course, the weather's been sufficiently warm not to require the heating on all day, so I'd have been extremely surprised, even astonished, had petrol prices risen during the July - August period.
Given a colder November, however, I can see a significant rise coming.