THE exclusive end of BMW's top selling range is getting a niche of its own.

Moving its mid-sized coupe and convertibles away from the mainstream, the Bavarian car maker is creating a new model line up - the 4 Series.

Priced from around £29,000 the 4 Series coupe will arrive in October. A convertible will follow and other likely members of the new 4 club will include an M performance version.

BMW is making no secret that the 4 Series coupe is a replacement for the 3 Series version which notched up some 50,000 sales in the UK since 2006.

In creating the 4 Series the plan is to deliver extra exclusivity, making the cars sportier and more dynamic to drive while still sensibly priced.

So for £31,575 - that's £540 more than a 3 Series coupe - comes the 420 diesel with a specification which includes leather upholstery, a digital radio and colour display screen, automatic xenon lights and a multi-mode drive control as standard.

According to BMW, the extra equipment available on the 4 Series adds up to a saving of some £1,000 compared to the 3 Series and the difference is even more marked further up the range.

The new coupe will be launched with a choice of three engines - the 420d and petrol powered two-litre 428 and three-litre twin turbo 435 models.

We have just tried out the diesel in entry level SE trim and the more powerful 435 M Sport range topper.

Both look the part with some sharp styling and a pure coupe roofline which cuts in well back into the boot.

A flat nose and long wheelbase accentuate the design and from the back it looks well planted with sturdy haunches.

Compared to the 3 Series it is not only an inch longer and almost two inches wider but the rear track is pushed out by more than three inches.

On the road that translates into a very sporty stance from any angle and although only a four seater, the cockpit is roomy and well appointed. Boot space is also greater at 445 litres which for a coupe is generous.

All versions incorporate BMW's eco technology and feature stop/start as standard.

The diesel was particularly economical and averaged almost 58mpg without any trouble - not far off BMW's official 60.1mpg figure. With emissions of 124g/km it is significantly cleaner than the 3 Series diesel coupe and for business users attracts a 19 per cent tax rate.

Although the drive control alters throttle response and feel in a variety of ways from eco to sports modes the 420d felt much more a cruiser than an out and out sports machine.

The 435 on the other hand had genuine venom with its 306bhp giving it a 0 to 60 time of 5.4 seconds.

Both cars we tried were six speed manuals - eight speed autos also feature in the line up - and even the petrol version was surprisingly economical given its performance, coming in at an average of 30.4mpg on a 90 mile trip where we recorded an average speed of almost 58mph.

Again that was close to the official figure of 35.4mpg and with emissions of 185g/km it falls into the 29 per cent tax banding for business users.

At £48,160 the 435 M Sport we sampled had almost £7,000 worth of extras fitted including sat nav, Internet connectivity and a head up display.

Nevertheless that's keen when compared to the opposition in the shape of the Audi A5 and the Mercedes C-Class and BMW will be adding all-wheel-drive xDrive versions to the new range come November.

The numbers game has already paid dividends for BMW when it created the 6 Series range back in 2004 which has gone on to spawn no less than 21 models including the £97,000 M6 Gran Coupe.

The 4 Series may not be quite so up market but it is classy, performs well and carries a badge that remains hugely desirable.