For those of you with Costco memberships you can normally get Castrol and Mobil much cheaper than any of the retail shops.
4L of Mobil 1 0W-40 for example in Halfords is £46. £22.99 Inc. VAT in Costco.![]()
Never have Edge though
Am the other way around...Just paid £12 for a 1L top-up - I remember the good old days when I'd by 5L of oil for my old car for about £8.