The second generation of the Mercedes-Benz B-Class celebrated its world premiere at the International Motor Show (IAA) in Frankfurt/Main in September 2011. While retaining the Sports Tourer concept, the vehicles in the 246 model series now boasted a significantly more dynamic appearance and further improved efficiency.
In this context, the almost 5 cm lower vehicle height compared to the previous generation and the lower but more upright seating position immediately caught the eye. A drag coefficient of just 0.26 secured the new B-Class the top position in its market segment with respect to aerodynamic overall design. To achieve this goal, numerous detailed refinements were required in addition to a particularly aerodynamic basic shape, for example an improved A-pillar geometry, an aerodynamically sophisticated exterior mirror housing, a large rear roof spoiler, innovative serrated wheel spoilers at the front and rear, and a consistently flow-optimised underbody. An ECO technology package available as an option for all B-Class versions offered further aerodynamic refinements such as a lowered suspension, joint sealing of the rear window and cladding on the rear suspension components.
Characteristic design features of the body included the accentuated width of the front and rear aspects, the tightly sloping roof line down to the rear spoiler, the pronounced wheel arches, dynamically shaped side sill panelling and, above all, the striking character lines along the flanks, which gave the hatchback a much sportier appearance than its predecessor.
The interior of the new B-Class reached a level of design and quality of finish previously unknown in the compact class. The Sports Tourer's famously spacious feel was combined with attractive design and high-quality surfaces, creating a special feel-good atmosphere in the interior. Eye-catching interior features included the large, three-dimensionally designed trim element, available in four versions, which extended over the entire instrument panel, the three large, round air vents in the centre and the seemingly free-floating TFT colour display above it, available in two sizes, with a galvanised surface and front facing in black piano lacquer. In addition, a 3-spoke steering wheel familiar from the CLS-Class and an instrument cluster with four analogue dial instruments gave the cockpit layout a sporty touch.
The drivetrain of the second-generation B-Class had also been completely modernised. At market launch, the range of available engines comprised two petrol and two diesel units. The former were of all-aluminium construction and featured two overhead, chain-driven camshafts, turbocharging and direct injection. Equipped with numerous efficiency-enhancing design features such as a regulated oil pump and variable water pump, the four-cylinder engines with a displacement of 1.6 litres came from the M 270 engine family and were initially available in two output levels: 90 kW/122 hp in the B 180 BlueEFFICIENCY and 115 kW/156 hp in the B 200 BlueEFFICIENCY. Good pulling power already available at just above idling speed and an economical fuel consumption were among the characteristic qualities of these engines, along with their smooth running. The combined fuel consumption for both output variants was around 6.0 litres per 100 km.
A new version of the OM 651 was used for the diesel engines, which had been extensively revised for transverse installation in the new B-Class. A reduced displacement of 1796 cc, a modified belt drive for the ancillaries and the modified installation position of the likewise new turbocharger, combined with technical features such as the two Lanchester balancer shafts and the common-rail injection system, which now had an injection pressure of 1800 bar, ensured impressive performance data with exemplary efficiency in terms of fuel consumption. The models initially available at the time of the market launch in November 2011 were the B 180 CDI BlueEFFICIENCY with 80 kW/109 hp and the B 200 CDI BlueEFFICIENCY with 100 kW/136 hp. With an average consumption of 4.4 l/100 km and corresponding CO₂ emissions of 114 and 115 g/km respectively according to the current standard, both models took top positions for fuel consumption and emissions in a competitive comparison.
Mercedes-Benz broke new technical ground with the 7G-DCT dual-clutch transmission designed as an automated three-shaft manual transmission, which became optionally available for the first time for the new B-Class generation and replaced the continuously variable AUTOTRONIC transmission used in the previous 245 model series. The efficiency of this transmission, which operated with no interruption of tractive power, matched that of manually shifted transmissions, as it did not require a hydraulic torque converter.
The compact, lightweight dual-clutch transmission was equipped with three shift programs. In ECONOMY mode, it shifted the gears at low revs to maximise fuel economy, while in SPORT mode it utilised the gears more fully and offered noticeably shorter shift and response times. In MANUAL mode, the gearchanges were left to the driver. In this case, the gears were changed using shift paddles behind the steering wheel – with even shorter shift and response times. The selector lever of the 7G-DCT transmission took the form of a steering column stalk and was positioned on the right behind the steering wheel.
Like the direct-shift transmission, the new 6-speed manual transmission developed in parallel had a wide spread of gear ratios, which resulted in high tractive power at low speeds on the one hand and a low engine speed level at high speeds on the other. The mechanical manual transmission, whose gears were engaged by cable, was similar to the DCT transmission in its basic architecture and had a dry weight of just 46 kg. It was standard equipment in each of the model versions offered at the market launch of the new B-Class.
The suspension of the new B-Class generation was noticeably more dynamic and more agile, but without compromising the familiar level of comfort. In addition to a decidedly lower centre of gravity, a new four-link rear suspension and a further development of ESP® with modified control interventions and an integrated torque vectoring brake functionality were primarily responsible for this. The latter counteracted any undesirable tendency to understeer. In addition, a newly designed electromechanical steering system ensured greater precision and road feel.
With a wide range of standard or optional assistance systems to increase safety and comfort, the new generation of the B-Class was at the top of its market segment in terms of accident protection and prevention. Equipping all versions with the radar-based collision warning system COLLISION PREVENTION ASSIST as standard was a world first. In dangerous traffic situations above 30 km/h, this provided a visual and acoustic warning of detected obstacles and prepared the Brake Assist for the most precise braking possible to help avoid typical rear-end collisions or mitigate their severity. The ATTENTION ASSIST drowsiness detection system was also standard equipment. Another first in the compact class was the availability of the PRE-SAFE® occupant protection system, which always went into action as soon as longitudinal and/or lateral dynamics entered critical i.e. accident-prone, areas.
Other optionally available assistance systems included automatic driving lights, Blind Spot Assist, Lane Keeping Assist, Speed Limit Assist, DISTRONIC PLUS adaptive cruise control, Active Parking Assist, a reversing camera and LINGUATRONIC voice control.
The new B-Class also benefited from the use of the latest multimedia generation from Mercedes-Benz. In addition to two differently customised navigation solutions, the COMAND Online information and communication system was available on request, offering Internet access and a wealth of functions previously reserved for much higher vehicle classes. An interface for mobile audio devices was also provided as standard.
The first examples of the new B-Class were delivered to customers in mid-November 2011. The list prices incl. VAT started at 26,001.50 euros for the petrol-engined B 180 BlueEFFICIENCY and ranged up to 29,809.50 euros for the diesel model B 200 CDI BlueEFFICIENCY.
Coinciding with the market launch, Mercedes-Benz also launched a limited-edition special model for a short time, which bore the familiar "Edition 1" name. In combination with all four initially available engine versions, it offered additional high-quality features such as the Sports Package – which included sport suspension, selective damping system, Direct-Steer system and 17-inch light-alloy wheels – bi-xenon headlamps, cruise control and a reversing camera. The list prices incl. VAT for these special models ranged from 28,405.30 euros for a B 180 BlueEFFICIENCY to 32,243.05 euros for a B 200 CDI BlueEFFICIENCY.
The first expansion of the engine range came around a year later, from autumn 2012. The focus was on a new top-of-the-range model in both petrol and diesel versions. The petrol-engined B 250 BlueEFFICIENCY, which was equipped with the 2.0-litre version of the M 270 direct-injection petrol engine configured for 155 kW/211 hp, was the first to be launched. The 7-speed dual-clutch transmission 7G-DCT was on board as standard. In this configuration, the compact space miracle delivered performance figures comparable to sports cars: The top speed was 240 km/h, and acceleration from 0 to 100 km/h took just 6.8 seconds. And all with a modest fuel consumption: According to the standard driving cycle valid at the time, the average petrol consumption of the B 250 BlueEFFICIENCY was at most 6.3 litres per 100 kilometres.
The B 220 CDI BlueEFFICIENCY, which was launched a little later, was hardly less powerful. Its drivetrain consisted of a version of the approximately 2.1-litre OM 651 four-cylinder diesel engine, which was boosted to 125 kW/170 hp thanks to two-stage turbocharging, and the 7G-DCT transmission which came as standard. In view of its driving performance, with a top speed of 220 km/h and an acceleration time of 8.3 seconds, the new top-of-the-range diesel model boasted record-breaking efficiency: the average standard fuel consumption was a maximum of 4.6 litres per 100 kilometres.
At the beginning of 2013, Mercedes-Benz added the bi-fuelled B 200 Natural Gas Drive to the B-Class model portfolio. In contrast to its predecessor from the T 245 model series, which was still available under the designation B 180 NGT BlueEFFICIENCY, the new model had a modified basic concept: the CNG drive, which had a particularly favourable emissions balance, no longer acted as a supplement to the petrol drive, as the use of these energy sources was reversed in the new model: Compressed natural gas was now used as the main propulsion system, and petrol only played a subordinate role. Instead of 54 litres as before, the petrol tank of the B 200 Natural Gas Drive only held 12 litres, while the gas tanks carried on board had a total capacity of 21 kg instead of the 16 kg provided in the previous model. With the 2.0-litre four-cylinder petrol engine delivering the same 115 kW/156 hp power output as the preceding model, this resulted in significantly better emission values – in addition to more favourable operating costs – while maintaining the same appealing performance level.
The following list prices incl. VAT applied to the new model versions when deliveries commenced: the B 250 BlueEFFICIENCY was priced at 34,391.00 euros, just under 1,000 euros less than the new top-of-the-range diesel model, and the B 220 CDI BlueEFFICIENCY at 35,283.50 euros. The alternatively fuelled B 200 Natural Gas Drive was priced at 32,368.00 euros in the new B-Class range.
At the New York International Auto Show held in spring 2013, Mercedes-Benz demonstrated to the public how seriously it was taking the development of all-electric vehicles. The B-Class Electric Drive, which was presented there as a world first, was intended to demonstrate how practicable locally emission-free driving could already be. The Electric Drive version was based on the conventionally powered B-Class, but was equipped with an electric motor with around 130 kW/177 hp, which provided powerful acceleration and was supplied with energy by a lithium-ion battery located in the underbody and protected from impact. The top speed of the B-Class Electric Drive was electronically limited to 160 km/h to achieve a range of approx. 200 km with a fully charged battery in accordance with the NEDC standard. State-of-the-art recuperation technology with energy recovery in overrun mode and when braking ensured the best possible energy efficiency.
Under the heading of Connected Services, the B-Class Electric Drive was also optimally connected. Via a vehicle homepage, which could be accessed on a PC or smartphone, it was e.g. possible to access the vehicle by remote enquiry and remote configuration to find out the current state of charge of the battery or the remaining range, which was displayed on a map. The vehicle could also be individually pre-cooled or pre-heated in this way. The radar-based collision warning system COLLISION PREVENTION ASSIST with Adaptive Brake Assist was also standard equipment in the B-Class Electric Drive.
Although the sales release for the electric vehicle was initially scheduled for the end of 2013, followed by the start of series production and a market launch in the USA, this process was delayed for a while. Continuous technical improvements ultimately meant that production of the Electric Drive version only began at the end of 2014, as part of the regular major facelift of the 246 model series.
In the new B-Class models powered by combustion engines, Mercedes-Benz once again expanded the range of available drive units to include a diesel engine and a petrol engine from summer 2013 onward. The entry-level engine in the B 160 CDI was now a 1461 cc common-rail diesel from the OM 607 series with 66 kW/90 hp. The four-cylinder engine was contributed by cooperation partner Renault, but had been sustainably refined in accordance with Mercedes-Benz specifications. At the same time, there was a change to the engine configuration of the previous B 180 CDI. The new OM 607 diesel engine with a displacement of just under 1.5 litres replaced the 1.8-litre diesel from the OM 651 engine family that had previously been used. The power output remained largely identical: the new engine was configured for 80 kW/109 hp and, despite a nominally smaller displacement, even delivered a 10 Nm higher maximum torque of 260 Nm. Above all, however, it shone with an almost 10 % lower average standard fuel consumption of 4.1 litres per 100 kilometres.
At the same time, Mercedes-Benz launched the B 180 CDI BlueEFFICIENCY Edition, a particularly efficiency-optimised model variant that was also based on the OM 607. The average diesel consumption of this 80 kW/109 hp version was just 3.8 litres per 100 kilometres according to the applicable standard. Numerous aerodynamic improvements, including a partial cover for the radiator grille and lowering of the suspension, a slightly reduced vehicle weight. and a higher ratio in the upper gears, significantly contributed to the reduction in fuel consumption.
In autumn 2013, the B 220 4MATIC was the first model in the new B-Class to feature the familiar permanent all-wheel drive, now with fully variable torque distribution. As in the B 250 – this and all other models with the corresponding designation had meanwhile dropped the "BlueEFFICIENCY" suffix – the power unit was a 2.0-litre version of the M 270. The turbocharged direct-injection petrol engine was paired with the automatic 7G-DCT dual-clutch transmission as standard, and delivered 135 kW/184 hp. The four-cylinder engine thus helped the compact Sports Tourer to achieve superior driving performance. Acceleration from 0 to 100 km/h took 7.5 seconds, and the top speed was 225 km/h. Nevertheless, the average standard fuel consumption remained a maximum of 6.7 litres per 100 kilometres.
Given its power deficit of almost 14 kW/20 hp, the B 160 CDI, which opened up the range as the new entry-level model, was positioned not too far away from its brother, the B 180 CDI, which was now powered by the same drive unit and had a list price incl. VAT of 28,262.50 euros. At 28,738.50 euros, the high-efficiency B 180 CDI BlueEFFICIENCY Edition was priced at around 500 euros more. As may be expected, the only all-wheel-drive model in the range, the B 220 4MATIC, was positioned in the upper price segment of the model series at 33,230.75 euros, but despite its higher performance and all-wheel drive it was still well below the top rear-wheel-drive diesel model, the B 220 CDI.
The production numbers showed an unusually clear structure up to the facelift in autumn 2014: the B 180 CDI BlueEFFICIENCY, known as the B 180 CDI from spring 2013 onward, and its petrol-engined counterpart, the B 180 BlueEFFICIENCY or B 180, were by far the most popular models in the series, with around 135,000 and just under 130,000 units, respectively. The B 200 BlueEFFICIENCY or B 200 and the B 200 CDI BlueEFFICIENCY or B 200 CDI followed at similar levels, with around 63,000 and 56,000 units, respectively.
The particularly powerful diesel and petrol versions fell well short of these figures, though the B 250 BlueEFFICIENCY and B 250 achieved a production figure of just under 12,000 units, and fewer than 5,000 units of the B 220 CDI BlueEFFICIENCY and B 220 CDI left the production plant in Rastatt from the time of its launch. As for the alternatively powered B 200 Natural Gas Drive, which also entered the market later, in early 2013, the statistics show that around 2,200 units were produced.
