In March 2008, Mercedes-Benz presented the facelifted 245 model series at the Geneva Motor Show. Although it had only been in the passenger car range for three years and despite its high sales figures, the B-Class models had already undergone a comprehensive technical and aesthetic overhaul. The main focal points of the update were environmental compatibility, economy and comfort.
With its innovative vehicle concept, which combined the exterior dimensions of a compact car with the spaciousness of an estate car, and the variability of a minivan with the safety level of a Mercedes-Benz passenger car, the B-Class – together with the R-Class – founded the new Sports Tourer category. As a versatile family touring and recreational car, the B-Class has established itself on the market with more than 325,000 units delivered worldwide since 2005.
The visual retouching of its exterior appearance as part of the facelift measures reflected the further development of the Mercedes-Benz design idiom. The first thing that caught the eye was the redesigned front end, with the radiator grille now featuring three horizontal louvres painted in metallic grey with chrome-trimmed highlights and a centrally positioned, integral Mercedes star. The shapes on the bumper, whose design emphasised the large lower air intake, and the bonnet were also modified. The more striking sweep of the three elements mentioned was a defining feature, giving the front of the car a more dynamic look.
The side view, which was characterised by the interplay between taut shapes and sharply drawn lines, now also appeared even more harmonious in all model variants of the B-Class thanks to exterior mirror housings, door handles and sill panels painted in vehicle colour. In addition, new wheel trims and light-alloy wheels further enhanced the appearance. At the rear, the tail lamps now had a new, vibrant look.
The interior of the B-Class, with its generous amount of space, large glass surfaces and high-quality feel, continued to offer a feel-good ambience, which was further emphasised by new upholstery materials and a new fabric design for the seats. The trim parts on both sides of the centre console, in the area of the gearshift lever and in the door panels were now finished in smoky grey diagonally brushed aluminium.
In terms of the drive system, the engine variants remained the same as on the pre-facelift B-Class, with one exception: in addition to the two direct-injection diesel engines (the B 180 CDI with 80 kW/109 hp and the B 200 CDI with 103 kW/140 hp) and the four petrol engines (B 150, B 170, B 200 and B 200 Turbo) continuing to cover the power range from 70 kW/95 hp to 142 kW/193 hp, the addition of the B 170 NGT BlueEFFICIENCY to the line-up meant there was now a model variant that could be operated particularly economically and environmentally friendly with both natural gas and premium petrol thanks to its bivalent engine. The abbreviation "NGT" stood for "Natural Gas Technology" and referred to the fact that this fuel was not the long-established liquefied petroleum gas (LPG), but in fact compressed natural gas (CNG), which was becoming more popular as an energy source at the time.
The bivalent drive was characterised above all by lower carbon dioxide emissions and more favourable overall costs. At 135 g/km, the CO₂ emissions of the B 170 NGT BlueEFFICIENCY in the NEDC driving cycle at that time were 17 % lower than those of the comparable model with a petrol engine. The overarching advantages of the drive system were particularly evident across the vehicle's entire life cycle: an analysis over a driving distance of 150,000 kilometres resulted in an overall CO₂ footprint that was around 20% more favourable than that of a comparable model with a petrol engine, while nitrogen oxide emissions were also 11 % lower and carbon monoxide emissions 54 % lower.
The bivalent drive also had tangible economic advantages: converting the fuel consumption of the B 170 NGT BlueEFFICIENCY from the indicated 4.9 kg of natural gas per 100 kilometres into the energy equivalent of petrol resulted in fuel costs per kilometre that were around 50 % lower than those of a purely petrol-powered version.
The 2034 cc version of the M 266 was modified for use as the bivalent variant's drive unit. Among other things, the four-cylinder engine was equipped with additional injection nozzles on the underside of the intake manifold and a pressure regulator with an electromagnetic shut-off valve mounted close to the engine, which controlled the gas flow and kept the pressure within the system constant. At 85 kW/116 hp, the B 170 NGT BlueEFFICIENCY had the same engine output as the B 170 petrol engine, but at 165 Nm it even delivered 10 Nm more maximum torque.
In addition to the petrol tank, this model version had a gas supply system with a total volume of 16 kg distributed across five additional tanks, which alone was sufficient for a driving distance of more than 300 kilometres. With an average standard fuel consumption of 7.3 litres of premium petrol and 4.9 kg of natural gas per 100 kilometres, the new B 170 NGT BlueEFFICIENCY had a total range of over 1000 kilometres. Which of the two energy sources was to be used to supply the engine could be determined at the touch of a button on the multifunction steering wheel. An electronic control unit ensured instant and smooth switching between the two energy sources – even while driving. The need to accommodate the gas tanks in the rear and below the footwell on the front passenger side reduced the boot space of the B-Class by around a third to 422 litres (according to the VDA measurement method), but there was still enough space for a family's luggage.
As part of the model update and with a view to increasing efficiency, the Mercedes-Benz developers had subjected the purely diesel and petrol-powered four-cylinder engines to detailed further development. In the two diesel models B 180 CDI and B 200 CDI, the average standard fuel consumption was reduced by up to 7 % to 5.2 – 5.4 and 5.4 – 5.6 litres per 100 kilometres respectively. As before, all models on offer were available with the AUTOTRONIC continuously variable automatic transmission upon request.
In terms of efficiency, the petrol engine models benefited in particular from the BlueEFFICIENCY version, which was made available for the B 150 and B 170 models from autumn 2008. Available exclusively with a manual transmission and equipped with the newly developed ECO start/stop function, intelligent alternator management and tyres with reduced rolling resistance, the average standard consumption values compared to the regular specification models were reduced by as much as 9 % to between 6.2 and 6.6 litres per 100 kilometres.
As was also previously the case, the safety equipment in the facelifted B-Class models remained exemplary. Standard features on board included two-stage front airbags, belt tensioners at the front and on the outermost rear seats, belt force limiters and active head restraints in the front, as well as ISOFIX anchors and head/thorax side airbags. Assistance systems such as ABS, the Electronic Stability Program ESP® and Brake Assist BAS were also included as standard. A new feature was the addition of automatic Hill Start Assist as standard in the ESP® system. The newly developed PARKTRONIC active parking assistant, which was available as optional equipment, could be seen as more of a comfort-enhancing feature. With the help of ten ultrasonic sensors, the system searched for suitable parallel parking spaces when driving past and automatically performed all steering manoeuvres while reversing.
The optional infotainment systems available were completely revised. Audio 5, Audio 20, Audio 50 APS and COMAND APS were available in a new generation of devices and, from Audio 20 upwards, offered a radio with dual tuner, a colour display, a Bluetooth interface for mobile phones, a CD player, automatic volume adjustment and an AUX-IN port in the glove compartment for external audio devices. The Audio 50 APS version was additionally equipped with a Europe-wide DVD navigation system and DVD drive, while the top-of-the-range COMAND APS model offered an even wider range of functions with hard disk navigation, a slot for SD memory cards and voice control.
In addition, a newly developed interactive media interface was available as an option, which allowed the use of an MP3 player, another external audio device or a USB stick as a storage medium for music. All external audio devices could be operated using the buttons on the multifunction steering wheel. Upon request, all infotainment devices could also be combined with the "Logic 7" surround sound system, which provided a special acoustic experience in the interior of the B-Class.
The gross list prices of the facelifted models set at the summer 2008 market launch ranged from € 23,443.00 for a B 150 to €30,404.50 for the top-of-the-range B 200 CDI diesel model, and initially did not differ from those of their predecessors. Similarly, the efficiency-optimised BlueEFFICIENCY versions of the B 150 and B 170, which were introduced shortly afterwards, were offered at the same prices as the basic models despite the corresponding additional equipment. Mercedes-Benz continued to pursue an extremely moderate pricing policy for the Sports Tourer model series, which only took into account the low general inflation rate at the time. New to the line-up, the B 170 NGT BlueEFFICIENCY with bivalent drive technology was initially priced at € 28,798.00.
Parallel to the launch of the revised B-Class models, Mercedes-Benz also presented a particularly extensively equipped special model called the "Grand Edition", which was only available until the end of October 2008. Highlights of the equipment offered included the continuously variable AUTOTRONIC transmission, bi-xenon headlamps, the Light and Sight Package, metallic paintwork, a panoramic lamella sliding sunroof, THERMOTRONIC automatic climate control, 17-inch light-alloy wheels, Seat Comfort Package, Sports Package, electric windows all round and the COMAND APS multimedia system with additional media interface. In the interior, upholstery, trim parts and floor mats from the designo range ensured a decidedly classy look.
With the exception of the B 170 NGT BlueEFFICIENCY, the "Grand Edition" special equipment could be combined with all engine variants. In view of the particularly high level of equipment, the gross list prices were increased significantly and ranged from € 35,795.20 for the B 150 to € 42,090.30 for a correspondingly equipped B 200 CDI.
The 2009 model year, which started in autumn 2008, saw a reorganisation of the model designations in the petrol-powered B-Class models. The B 150 and B 150 BlueEFFICIENCY became the B 160 and B 160 BlueEFFICIENCY respectively, while the B 170 and B 170 BlueEFFICIENCY went by the new name of B 180 and B 180 BlueEFFICIENCY respectively. The previous B 170 NGT BlueEFFICIENCY was also renamed to the B 180 NGT BlueEFFICIENCY. B 200 and B 200 Turbo petrol models were unaffected by these changes. Although there were no changes to the technical specifications of the models affected by the renaming, a clearer structure was introduced for the transmission assigned as standard to each model: the AUTOTRONIC automatic CVT transmission was now standard on the B 160 and B 180, while the manual 5-speed gearboxes were reserved for the BlueEFFICIENCY versions, as before.
This naturally had an impact on the gross list prices for the B 160 and B 180. At € 26,061.00 and € 27,727.00, respectively, both model variants were now around 10 % more expensive than the respective BlueEFFICIENCY versions.
With the 500,000th vehicle already having rolled off the Mercedes-Benz production line in Rastatt, by 2009, the B-Class had not only made a name for itself as a stable best-seller but also served as the basis for a promising Mercedes-Benz project in the field of alternative drive systems, which were increasingly coming into the spotlight at the time. From the end of the year, the B-Class F-CELL was launched in a small series of around 200 vehicles and handed over to a select group of customers in Europe and the USA for everyday use. This vehicle was an electric car powered by hydrogen fuel cells.
The vehicle had already undergone extensive testing under demanding weather conditions in spring 2008. The new generation of the fuel cell drive was used in the B-Class F-CELL, which was much more compact and, at the same time, more powerful than the one used in earlier test vehicles. The optimised fuel cell system that Mercedes-Benz had already presented in 2005 in the F 600 HYGENIUS research vehicle served as the technical basis.
The electric motor acting as the traction drive developed a peak output of 100 kW/136 hp and a maximum torque of 320 Nm. The B-Class F-CELL thus fulfilled dynamic driving requirements above the level of a 2.0-litre petrol engine. Nevertheless, the fuel cell module of the compact Sports Tourer consumed the equivalent of just 2.9 litres of fuel (diesel equivalent) per 100 kilometres. The 3.7 kg of hydrogen on board were stored at a pressure of 700 bar in special tanks, which were safely housed in the sandwich floor of the B-Class.
In the fuel cell, the hydrogen reacted with atmospheric oxygen, releasing electrical energy to power the electric motor and producing water vapour as the only local emission. A lithium-ion battery with a nominal capacity of 1.7 kWh was used as the energy storage medium. Power was transmitted via an automatic single-speed direct-drive transmission. The B-Class F-CELL offered a range of around 400 kilometres and was thus suitable for everyday use, especially thanks to the short refuelling time of around three minutes. However, the implementation of locally emission-free mobility, which, in contrast to the fully electric drive, was also feasible over longer distances and without lengthy charging times, required the complex and costly construction of a nationwide hydrogen supply infrastructure.
Three B-Class F-CELL vehicles attracted a great deal of media attention when they set off on a 30,000-kilometre tour across four continents and 14 countries at the end of January 2011 to demonstrate the technical maturity of the locally emission-free electric drive with fuel cell and the general suitability of alternatively powered vehicles for everyday use. The first leg of the journey was from Stuttgart via Paris, Barcelona and Madrid to Lisbon. After this, the route then covered a distance of 7,500 kilometres across North America. More than 5,000 kilometres were then driven on the Australian continent in an east-to-west direction from Sydney and Melbourne to Perth. This was followed by a 10,000-kilometre route through Asia, starting in Shanghai. The final stage led via Moscow and St Petersburg through Finland, Sweden, Norway and Denmark. On the last of the 70 days on the road, the vehicles drove back from Hamburg to Stuttgart.
The B-Class F-CELL was accompanied by four Viano people carriers and four Sprinter vans, which acted as support vehicles. The latter were responsible for the mobile supply of the required hydrogen. The refuelling unit installed for this purpose was developed by Mercedes-Benz in close co-operation with the Linde Group, which ensured the supply of hydrogen throughout the tour thanks to its relevant expertise and international presence.
Less efficient and future-oriented, but firmly anchored in the here and now, was a spectacular project also carried out at the Mercedes-Benz plant in Rastatt at the beginning of 2011. Twelve trainees transplanted a 5.5-litre M 273 V8 engine with 285 kW/388 hp and a 7-speed automatic transmission into a B 200 CDI, creating a one-off that was christened the B 55.
The training object was not allowed to differ significantly from a production vehicle in terms of space concept, external appearance or suitability for everyday use. In order to achieve these specifications, extensive conversion work was required, in particular due to the necessary changeover from front to rear-wheel drive. In doing so, they drew on the parts pool of various Mercedes-Benz passenger car model series.
Built entirely in the Rastatt training workshop, the outward appearance of this one-off vehicle painted in white gave little indication of what it was capable of. The unique model only weighed 160 kg more than a standard B 200 CDI and is said to have taken little more than 5 seconds to accelerate up to 100 km/h.
While this very special B 55 aroused the interest of the well-known specialist magazines in particular, all of the production models offered in the 245 series remained largely unchanged in the production programme until June 2011. The new generation of the B-Class, now belonging to the 246 model series, celebrated its world première three months later at the Frankfurt Motor Show.
In terms of production statistics, the Sport Tourer concept proved to be extremely successful. In total, more than 740,000 units of the compact model left the Mercedes-Benz plant in Rastatt between 2005 and 2011. The annual production figures were characterised by unusual stability, with the exception of the launch and phase-out years: Neither the increasing waiting times nor the 2008 model update caused any dramatic upward or downward swings. With the exception of a slight dip during the global crisis year of 2009, when around 100,000 vehicles were still produced, the B-Class always reached annual production figures of between 120,000 and 135,000 units.
The B 180 CDI was consistently the most popular model, accounting for almost 234,000 vehicles over the entire production period. The petrol-powered B 170, known as the B 180 from 2009, came a distant second with around 158,000 units (including the BlueEFFICIENCY versions). Less popular was the entry-level model in the form of the B 150 and B 160, of which a total of just under 65,000 vehicles (also including the BlueEFFICIENCY versions) were built. In contrast, the powerful B 200 Turbo performed astonishingly well, with more than 26,000 units delivered between 2005 and 2011.
