BMW 535i SE Automatic

Price: £38,795
Top speed: 155mph
0-62mph: 6.2 seconds
Consumption: 33.6mpg
CO2 emissions: 195g/km
Best for: German understatement
Also worth considering? Audi A6, Jaguar XF, Mercedes E-Class

I don't know whether the Greeks had a word for it but the Germans certainly do: Verschlimmbesserung. Roughly translated, it means a supposed improvement that actually makes things worse, a notion that will surely be familiar to customers of British banks and students of British local authority refuse-collection schedules. So far, though, the motor industry hasn't seen too many examples of Verschlimmbesserung; today's cars are generally faster, safer, more reliable, more comfortable and greener than their immediate predecessors.

Now I don't want to suggest that the latest BMW 5-Series represents a backwards step compared with its popular predecessor – quite the reverse, in fact. But where this finely-honed, hard-to-fault machine is concerned, not all progress is of the unambiguous sort.

First, there are the new car's looks. The previous 5-Series, produced under the leadership of former design chief Chris Bangle, still looked fresh after seven years of production. Its replacement is, by comparison, a bland, if conventionally handsome affair. That will suit the many buyers who found Bangle's approach too daring, but I think this timidity is a mistake, especially at a time when Jaguar has rediscovered its long-lost gift for producing visually exciting cars.

The second area of Verschlimmbesserung is one that only enthusiasts will appreciate. One of the best reasons for buying a BMW with an in-line six-cylinder petrol engine – a type with which the company was particularly associated – was the way it sounded. Those engines didn't have much mid-range heft so they had to be worked hard to give their best, and they sounded great while they were at it. This week's test car, a 535i, also had an impressive straight-six engine, better in every objective sense than those that came before; no previous BMW six could match its power, economy and low CO2 emissions. The problem is that while BMW's old sixes were, in aural terms, an ever-present delight, the new ones are hardly heard at all. Twin turbo-chargers mean the 535i has power everywhere, and rarely needs to be extended, while the long ratios of the 8-speed automatic gearbox keep revs down too; improved sound-proofing does the rest.

What's needed here is the opposite of Verschlimmbesserung. BMW needs to find the courage to make this car slightly worse in order to make it better – in short, if it were noisier it would be nicer.