You can buy a diesel X5 for less, though, and if you're not in a position to benefit from the 40e's attractive company - car tax rates, an X5 sDrive25d may work out more cost - effective, particularly if you make a lot of longjourneys.
«[Fifteen] per cent of the UK's carbon dioxide emissions come from cars, and a quarter of our carjourneys are less than two miles long», states Brenda Boardman of Oxford's Environmental Change Institute (6).