BMW’s X5 has, quite rightly, established itself a place at the top end of the soft-roader market. Described by the company as a Sports Activity Vehicle, the X5 brought on-road handling to new levels for a 4WD when first launched, and only now is it beginning to cop some serious competition in the form of the Porsche Cayenne, Volvo XC90 and – maybe – the Volkswagen Touareg. But the broadening range of X5s helps to ensure the BMW’s place on the market and the new turbo-diesel version adds a dimension that may become increasingly important in the 4WD market – fuel economy. Like most modern turbo-diesels, the BMW sacrifices neither performance nor on-road refinement. It prompts the question - why aren’t all SUVs like this?