agree w AC
"There is a direct relationship between the power output of an engine and the amount of fuel that it burns. "
...correct, and since our beloved government insists on taking 65p tax for every litre of fuel burnt, dont you think that the porsche/4x4 drivers of this world are already being taxed more for owning their vehicles than your average 1.2L vehicle?
grrrrrr
(I dont own a car either, I cycle, and Kens CC hasnt reduced the number of cars in london during my commute.)