Indeed, here's a breifing paper for the UK House of Commons that discusses the price relationships: http://www.parliament.uk/briefing-papers/SN04712.pdf http:/

Indeed, here's a breifing paper for the UK House of Commons that discusses the price relationships: http://www.parliament.uk/briefing-papers/SN04712.pdf http://www.parliament.uk/briefing-papers/SN04712.pdf Basically demand is the driver of prices, with diesel engines becoming more popular year-on-year but the refineries unable / unwilling to commit more production to diesel because that leaves them with a surplus of less-desirable products from the refining process, too. The result is that the UK imports diesel and exports petrol.