BMW is describing its new 3 Series Saloon, which hits the streets later this month, as a car of contradictions.

It is larger and more spacious than the model it replaces, but lighter, quicker, more fuel-efficient and agile - yet even safer.

And the prestige marque is heralding big steps forward in style, quality, comfort and specification for only a minimal price increase.

According to BMW, this sixth generation of 3 Series builds on the outgoing model's position as the ultimate drivers' car in its sector, but is also a logical business proposition thanks to new engines and EfficientDynamics emissions-reducing technology

From launch there will be four models - 320d, 320d EfficientDynamics, 328i and 335i - to be quickly followed next month by three new engines.

They will be 316d and 318d diesels, powered by 116bhp and 143bhp variants of the 2.0-litre diesel engine, plus another version of the 2.0-litre turbocharged petrol engine, which will slot into the new 320i, and be tuned to deliver 184bhp.

By this time there will be eight 3 Series saloons with emissions at or below 120g/km.

The EfficientDynamics technologies featured in the previous series have been supplemented with new ones, meaning Auto Stop-Start is fitted to all versions along with Brake Energy Regeneration and lower rolling resistance tyres.

BMW is also offering an eight-speed automatic gearbox across the range, giving a wider spread of ratios, as an alternative to the standard six-speed manual.

The familiar ES, SE and  M Sport trim grades will grace the new cars but BMW is adding Sport, Modern and Luxury models, each with a distinct character.

It mirrors the ‘Lines' range first showcased on the BMW 1 Series launched last year and even the trim on the key fobs differs between the various versions.

All models will come with more kit than before and include 17-inch light alloy wheels, automatic air-con, Bluetooth, BMW Professional radio with 6.5-inch colour screen and iDrive, keyless starting, USB, a multi-function leather steering wheel, cruise control and automatic boot opening.

SE is available with all engines except the 335i, and adds different alloys, rear Park Distance Control, two-zone aircon and a rain sensor with automatic light activation, for a premium of £850.

Sport and Modern versions are priced £1,000 above the equivalent SE, while the difference between SE and Luxury is £2,500.

New safety options include a full-colour Head-Up Display which shows current speed limits, the car's current speed and turn-by-turn instructions when a BMW navigation system is fitted.

Dynamic Safety is another feature offered which tensions the seat belts and closes any open windows or the sunroof if an accident seems imminent.

Internet access via the owner's mobile telephone and BMW's new Real Time Traffic Information service, which delivers faster, more accurate warnings of traffic hold-ups and even offers suggestions on how to avoid them, are among the media services available as part of BMW ConnectedDrive.

Prices for the new 3 Series Saloon start at £24,880 for the 316d ES model which joins the party next month. Entry to the range from launch will be the 320d at £28,080, while the 328i petrol model is from £29,060 and 335i from £35,525.

BMW says that towards the end of 2012 it will introduce four-wheel-drive and hybrid powertrains to the 3 Series Saloon for the first time in the UK.

The xDrive all-wheel-drive system has been available on the 3 Series in some markets previously, and has now been engineered for right-hand-drive cars.

And the ActiveHybrid 3 will arrive at roughly the same time, and will pair the 335i's 306bhp six-cylinder engine with an electric motor.