Well.. I always used to fill up at Tescos (53 reg A3 2.0L TDI Sport)... but the other day I filled up at Esso, and I was very surprised.. on my work run (8 miles) I seem to be averaging 3-5mpg more.. I'd never seen 51mpg on this car before.. Always thought that diesel was diesel.. Clearly not.. Working it out it looks like over a tank I'd be getting the equivalent of about a gallon more in terms of mileage over the tesco stuff.. so the 50p extra per tank in cost for filling up at Esso is completely obliterated by the ~£5 saving in mileage.. So.. I was wondering whether people had a particular favourite. Any comparison figures out there?