First details: Benz bowls up next B-class

MERCEDES-BENZ has fired off its next-generation B-class salvo almost a year ahead of Australian sales in the second quarter of 2012.

More than 30 technical images and full details – including new petrol and diesel engines, a new dual-clutch transmission and class-leading aerodynamics - of the all-new B-segment hatchback have been released two months before it debuts at the Frankfurt motor show in September.

However, Benz is keeping at least some of its powder dry until then by revealing only partial interior and exterior images, including a backlit side profile shot that confirms the second-generation B-class will shed its tallboy stance in favour of a sleeker, low-slung design not unlike the M-class wagon, the third-generation of which will also debut at Frankfurt.

On sale in Europe from November, the MkII B-class replaces the five-door first launched in Australia in November 2005 and will be joined here by the end of next year by a redesigned MkIII A-class, as previewed by the striking A-class concept at the Shanghai show in April.

In the absence of the smallest Mercedes model, Australian sales of the original B-class have bounced by almost 40 per cent to more than 1200 sales in the first half of this year, aided by a special-edition Anniversary Package from last month.

That is on top of a near-185 per cent sales surge last year to 1950 sales, following a range-wide repositioning and the discontinuation of the slow-selling A-class in January 2010, putting the B-class ahead of its most direct compact premium rivals in the BMW 1 Series, Audi A3 and this year’s new Lexus CT200h hybrid.

But that hasn’t stopped the German giant developing a replacement that Mercedes claims brings more advances than any other model in its long and illustrious history.

“No model change in the history of Mercedes-Benz has ever seen so many new developments introduced in one fell swoop,” says Mercedes-Benz Cars board member for group research and head of development, Dr Thomas Weber.

“Future B-class customers will benefit from this quantum leap in terms of exemplary low fuel consumption and CO2 emissions combined with driving pleasure, plenty of space and the customary high standard of safety from Mercedes-Benz.”

Bigger in all direction except height, the 2012 B-class is about 90mm longer at 4359mm and about 10mm wider at 1786mm, but comes with a 1557mm roof height – almost 50mm lower than before.

In response to customer demand and thanks to seats that are 86mm closer to the road, however, Mercedes says all five seating positions are more upright, while increased front headroom of 1013mm is said to make the B-class one of the most spacious in its class.

As part of the car’s Easy-Vario-Plus seating system, the rear seats can slide fore-aft by 140mm and the front passenger seatback can be folded onto its base.

Mercedes says the new B-class is based on an enhanced version of the current model’s ‘sandwich floor’ design, which can be modified to accommodate alternative drive systems, presumably including the hydrogen fuel cell technology showcased in the current B-class.

Here and now, however, the compact front-wheel drive ‘sports tourer’ comes with a best-in-class aerodynamic drag co-efficient of just 0.26Cd thanks to attention to details including air flow around the front wheels, cooling airflow and underbody design.

While a patented serrated wheel-arch spoiler and, on base petrol models, an active radiator shutter will be standard, Benz says an optional ‘Eco Technology’ package will see the new B-class match the “world-class” aerodynamics of the E-class coupe (0.24Cd) - despite its wagon-shaped rear-end.

Available across the range, the fuel-saving eco-pack includes a lower ride height, sealed rear window joints and the cladding of chassis components at the rear axle.

Matched as standard across the range with a fuel-saving idle-stop system, a brace of new turbocharged engines and manual and automatic transmissions – all developed in-house – is headlined by the debut of the new M270 1.6 and 2.0-litre four-cylinder petrol engine family.

Fitted with the same third-generation direct-injection system that debuted last year in the BlueDirect V6 and V8 (making the B-class the first car in its segment to feature direct-injection, says Benz), the new turbo-petrol four is designed for both transverse and longitudinal applications and debuts in the new B180 in 90kW/200Nm 1.6-litre guise.

Also producing its peak torque figure from 1250rpm is a 115kW/250Nm version in the B200. Benz says the compact engine design allows one of the best front-wheel drive turning circles on offer, at less than 11 metres.

The new B-class’ common-rail turbo-diesel engine is a development of the OM651 oil-burner already seen in Europe’s C-class and S-class since 2008, featuring third-generation direct-injection and down-sized displacement of 1.8 litres via a shorter stroke.

Although no fuel efficiency figures have been revealed, the first transverse application of the new diesel engine sees the B180 CDI produce 80kW and 250Nm of torque from 1400rpm, and the B200 CDI produce 100kW and 300Nm of torque from 1600rpm.

Matched with the new engines is Mercedes’ brand-new 7G-DCT seven-speed dual-clutch automated manual transmission, which is claimed to be super-compact, light in weight, adaptable to a wide range of engines and engine speeds and able to shift gears “without any interruptions in tractive power”.

Hence, Benz says the 7G-DCT, which is closely related to the B-class’ new six-speed manual gearbox and also incorporates an idle/stop-compatible electric oil pump, combines the comfort of an automatic with the efficiency of a manual transmission.

Meantime, a lower centre of gravity, new four-link rear axle and upgraded ESP electronic stability control are claimed to substantially increase the car’s dynamic performance without compromising ride comfort.

A 20mm-lower sports suspension package comprises amplitude-selective sports dampers and a ‘direct-steer’ system in place of the redesigned electro-mechanical variable-ratio steering system, which is said to aid efficiency and deliver a noticeably more direct steering ratio.

Benz claims another first in the compact vehicle segment with the standard fitment of a radar-based collision warning system with adaptive brake assist to lower the risk of rear-end collisions.

It says it expects Collision Prevention Assist, which provides a visual and acoustic warning to alert drivers of potential obstacles and prepares the brake assist system for optimum retardation during “emphatic” brake pedal applications, to significantly reduce the incidence of 30km/h-plus rear-end crashes.

Attention Assist and an electric parking brake will also be standard in the 2012 B-class and, while manual versions will get a hill-hold function as standard, 7G-DCT models will offer a brake-hold function.

Optional safety features will include Adaptive Headlamp Assist, Blind Spot Assist, Lane Keeping Assist, Speed Limit Assist, Active Parking Assist, Linguatronic voice control, a reversing camera, Distronic Plus radar cruise control and, in another claimed first for the compact class, the Pre-Safe collision preparation system.