##BMW 3 saloon--left##WITH the 2002 CO2-based BIK tax regime expected to pave the way for a resurgence in the popularity of diesel, and new emissions-based Vehicle Excise Duty already with us, you might expect BMW to be at the top of the learning curve with regard to a tax-friendly product. And true to form, it is. The 320d's 2-litre direct injection turbodiesel develops 136bhp and returns 49.6mpg on the combined cycle, making it one of the most efficient units on the market. Available in both four-door saloon and five-door Touring estate guises, the 320d starts at £20,570 on the road for the standard saloon, and rises to £22,660 for the 320d SE Touring. Tested here is the 320d SE saloon, at £21,800 on the road.