This is quite a short report, and it's here to underline our appreciation of BMW's phenomenal second-generation common rail three-litre turbo diesel engine. Whatever more powerful petrol engines appear in the new 5-Series range, it's unlikely that any of them will match the tremendous push in the back provided by the 530d - and, of course, they won't get anywhere near its economy figures.When the first version of this engine appeared four years ago, it was regarded as pretty hot stuff - hot enough, as BMW is rather wickedly recalling, for Jenson Button, officially under-age to take the wheel of a really powerful petrol-engined car on the public roads rather than the race circuits of France, but able to drive any kind of diesel, to be done for speeding by some bemused gendarmes.We've already experienced the second-generation engine in the new 7-Series, but despite whatever weight-saving measures have been taken in the bigger car, the effect of the engine in the still lighter 5-Series is stunning.In the 5-Series launch report we rather overdid the new engine's power output, by printing the European horsepower rather than the UK-style figure. Okay, it was only a 4bhp error, and any three-litre diesel which turns out 214bhp at 4000rpm is quite something anyway. But it's the maximum torque that really grabs the attention, out on the road every bit as much as in the specification table.The 530d pushes out almost 370lb/ft at 2000rpm, and the effect of that when you decide to give it the works going up a hill, or pull out to overtake, is no less invigorating than doing the same in an M5. And the old complaint about turbo diesels being leisurely off the line has no place here: if you took the 0-60mph figure rather than the 0-62, it would be no more than 7.0 seconds.It's worth bearing in mind that the 530d is geared differently from the launch petrol models. The 520i and 530i get to their top speed in fifth, with sixth there to act as an overdrive, reducing the engine revs. The 530d is designed to reach its remarkable 152mph maximum in sixth because, as BMW says: "The focus in the development process was on superior performance."There's no hesitation about cranking up the engine, either. Unless the outside temperature is under five degrees Centigrade, it's designed to start immediately.On a motorway the 530d simply wafts along, and the other significant thing is that it does so while just sipping fuel. An extra urban figure easily above 51mpg hardly seems to fit with the kind of performance that's available.As far as company car tax and all that is concerned, the 530d is rated in the Euro III bracket rather than being Euro IV compliant, but you can't expect absolute miracles.