It may not seem obvious, but the flanks of the new BMW 5 Series are intended to mimic the surface of a Zeppelin airship. The crease along the car's waist is a fuselage spar, while the surface below is intended to emulate the tension of a blimp's enveloping fabric. The 5 Series body bears physical evidence of some thinking that, at best, might be termed unusual.
This car is the latest subject - or victim - of the new aesthetic sweeping the BMW range. It was created by US designer Chris Bangle, whose controversial designs are making him the most questioned car designer of all time.
It's not that he has altered the essential form of the 5 Series so much as the detail. The interior is a striking meld of intersecting planes and shapes, but the eye is unable to cope with the resulting visual dissonance.
The stretched headlights, a bootlid that appears to float above the rest of the body and strange concavities in the doors seem to amount almost to wilful disfigurement.
Handsome, spacious and luxurious, the old 5 Series was an unrivalled executive car. That isn't quite true of the new model. BMW has had to grapple with replacing a product that was hard to improve, but you can't accuse it of not trying. The latest 5 is almost entirely new, with only a few items carried over from the old model.
Mechanically, the new 5 is a little less controversial. It's powered by a range of straight-six engines, including a highly effective turbodiesel, you can choose from automatic and manual transmissions, it has rear-wheel drive and suspension honed to deliver high standards of ride comfort, stability and driving enjoyment. You can also order the car with a couple of mechanical niceties, such as Active Steering for pounds 810.
Active Steering sounds simple enough. At lower speeds it speeds up, smaller swivels being required to round a corner - useful in town - while at high speed the gearing reduces, bigger swings being needed for lane changes.
That sounds great, except that your brain has to recalibrate every time you drive from town to country, and vice versa. Mostly you adapt, but you can occasionally be caught out.
You can also order Dynamic Drive (pounds 1,550), a suspension option that prevents the car heeling over in corners. On tight, twisty roads, the combination of this and Active Steering turns the 5 Series into a sports car of stunning agility.
If you want a car that will plough the major arteries of the country in maximum comfort and tax-minimising economy, I recommend the 530d variety. The diesel motor pulls like a (foreign) train, it can be mated with a superb six-speed automatic gearbox and it's startlingly economical for an engine of such potency.
But there are disappointments: too much road noise on coarse surfaces, and the wheels do not ride bumps with sufficient serenity. The multi-function iDrive control is cumbersome, while the multifarious options found on the price list make it easy to order a sub-optimal car. I'd suggest a 530d automatic without the run-flat tyres (they spoil the ride), and without Dynamic Drive and Active Steering.
Even in this optimised specification, the new 5 Series still feels slightly flawed. In the fundamentals, it's excellent and finely crafted. But BMW's struggles to reinvent the 5 are evident.
< SPECIFICATION BMW 530d Price pounds: 30,950 Max power: 218bhp Max torque: 369lb ft Max speed: 151mph 0-60mph: 7.2sec Fuel consumption: 33.6mpg CO2 emissions: 208g/km
- Audi A6 2.5 TDi Quattro SE - pounds 29,710 - To be replaced late next year. Less powerful than the BMW.
- Mercedes E 320 CDi Elegance - pounds 33,560 - Pricey but supremely comfortable mile-eater, with a great ride and an excellent engine.