ONE of the world's favourite executive expresses, the BMW 5 Series has been transformed for a new age.

More refined than ever, significantly lighter and very agile, the new 5 Series is the personification of premium saloon motoring.

It immediately becomes unique in its class for technology, structure and materials.

Leading the charge to net well-off business and private users is a newly developed modular engine range featuring a lightweight thermodynamic all-aluminium construction.

The previous model had a high reputation for handling, but the new kid on the block features sharply honed agility and precise driving qualities thanks to a redesigned chassis and some very intelligent engineering.

There is also a significantly upgraded and intensely driver-focused interior which brings some innovative cutting-edge features such as a raft of driver-assistance features, gesture control, remote parking and the advanced BMW display key.

It is hard to believe that the 5 Series is now in its seventh generation. I remember driving one of the first to come into this country at the dawn of the 1970s, a beautifully built car that demanded a degree of skill from the driver to keep the tail from wagging under the punch of its six-cylinder petrol engine.

The high quality of construction and power is still there but the driving qualities of today's 5 Series which I experienced recently are light years ahead of the original.

This was the 520d M Sport which tips the price scale at £38,920 and takes head on the best that the competing manufacturers can throw at it.

It has to be exceptional in these demanding times to take on opposing saloons from rival manufacturers such as Mercedes-Benz, Volvo, Jaguar and the like.

The 520d is the model that has company drivers of the edge of their seats because of its 68.8 combined mpg figure and 114g/km CO2 emissions figure.

For its 190bhp output, the diesel unit of the 520d is capable of 146mph performance with a 7.5 second 0-62mph sprint.

For me, one of the most significant features is the torque factor of 400Nm which is pulling power par excellence.

And another weapon of mass attraction is the car's looks. Slightly longer, taller and wider than the outgoing model, the new 5 can really strut its stuff on the style catwalk.

It features a big out-thrust bonnet with the traditional BMW kidney grille with swept back headlight covers leading into the straight classic lines of the car.

Also, the more generous proportions of the new model provides more headroom, plus an absolutely massive boot of 530-litre capacity.

Itn virtually every way the new 5 Series feels more roomy and in keeping with the demands of the discerning drivers who get behind the wheel of cars such as this.