In message , at
20:57:45 on Mon, 29 Aug 2005, Martin Underwood remarked:
For some reason, the rises in the price of fuel over the past few
months have affected diesel prices more than petrol: going back a few years,
diesel used to be slightly cheaper than petrol, then it drew level and
became 1-2 pence/litre more expensive, but stilll cheaper than leaded or
lead-replacement petrol; now it's consistently the most expensive fuel on
the forecourt, typically 5 pence/litre more than unleaded. Since the fuel
duty (a fixed rate that's not dependent on the raw material cost) hasn't
changed, I'm not sure what's happened.

When oil is refined, it's expensive to change the types of fuel that are
produced (away from some "natural" mix of petrol/diesel etc). I expect
that the demand for diesel has increased enormously, so the price rise
reflects a relative scarcity.
--
Roland Perry