BMW introducing 2 Series Active Tourer at Geneva; new 3- and 4-cylinder engines, front-wheel drive
14 February 2014
|The new compact 2 Series Active Tourer. Click to enlarge.|
The new compact BMW 2 Series Active Tourer will celebrate its world premiere at the upcoming Geneva Motor Show. The 2 Series Active Tourer follows the Coupe as the second member of the new BMW 2 Series line-up and features new 3- and 4-cylinder gasoline and diesel turbocharged engines, front-wheel drive (BMW’s first), EfficientDynamics technology and ConnectedDrive.
The new engines are mounted transversely and feature a compact design along with BMW TwinPower Turbo technology, at the same time as complying with the EU6 emissions standard. Fuel consumption (provisional) for the 2 Series Active Tourer will range from 6.0–4.1 liters per 100 km (39–57.4 mpg US) on the European combined cycle, with CO2 emissions ranging from 139–109 g/km.
The standard transmission is a newly developed six-speed manual unit. Optionally, in conjunction with the three-cylinder engine, a 6-speed Steptronic transmission can be specified. For the four-cylinder models a new 8-speed Steptronic transmission has been developed, which is specially adapted to take account of the front-wheel-drive configuration and the transverse engine. All transmissions feature Auto Start Stop, while the Steptronic versions further improve vehicle efficiency with a coasting function.
Common to all the new engines used in the BMW 2 Series Active Tourer is their in-line configuration and a displacement per cylinder of 500 cc. The ultra-low-friction, all-aluminium core engine features optimized thermodynamic efficiency, very low weight and refined running. The closed-deck crankcase is very rigid, while thermally joined cylinder liners with twin-wire, arc-sprayed coating save weight and reduce friction. A balancer shaft (in the three-cylinder engine) or two counter-rotating balancer shafts (in the four-cylinder engines) ensure refined running throughout the engine speed range. Further features common to the engines include standardized interfaces such as the identical engine mounts or the connections for the cooling system, intake and exhaust systems and heating and air-conditioning system.
All the gasoline engines feature an exhaust-manifold-integrated turbocharger, with liquid cooling not only for the manifold but also for the aluminium turbine housing. The exhaust gases have only a short distance to travel to the turbocharger system, ensuring agile response, while the very short warm-up time reduces internal friction in the system and therefore also fuel consumption. Finally, the close-coupled location of the catalytic converter and the electrically operated boost pressure control valve (wastegate) help to reduce the emissions of these engines.
All gasoline and diesel engines in the new engine family are equipped with the latest version of BMW TwinPower Turbo technology. The gasoline engines feature turbocharging, direct gasoline injection, double-Vanos variable camshaft timing and, for the four-cylinder units, Valvetronic fully variable valve timing. On the thermodynamically optimized diesel engines, VNT turbocharging and common rail direct injection with a maximum pressure of 2,000 bar form part of the package.
|Output and torque diagram, 218i. Click to enlarge.|
218i Active Tourer. The new 1.5-liter three-cylinder gasoline unit—which made its debut in the i8—premieres in the new series in the BMW 218i Active Tourer (fuel consumption city/highway/combined: 6.1/4.2/4.9 l/100 km [38.6/56/48 mpg US]; CO2 emissions combined: 115 g/km) with the six-speed manual gearbox.
The turbocharged three-cylinder gasoline engine delivers maximum power of 100 kW/136 hp between 4,500 and 6,000 rpm. Peak torque of 220 N·m (162 lb-ft) is available from 1,250 rpm. For short periods this can be increased to 230 N·m (169 lb-ft) using the overboost function. The extra torque is particularly useful for overtaking or on uphill gradients and can be utilized at engine speeds up to 4,150 rpm.
Further advantages of this lightweight, compact three-cylinder engine are its vibration characteristics. As in a six-in-line engine, there are no first and second-order inertia forces. In a further contribution to smoothness, the small amounts of engine roll torque are completely eliminated by a balancer shaft for maximum refinement throughout the engine speed range. Finally, the combination of a dual-mass flywheel and a centrifugal pendulum absorber, which is unusual in this power class, eliminates irregular running, ensuring refinement even at the low end of the engine speed range.
Further advantages of the three-cylinder engine include longer firing intervals, making it possible to precisely match the engine cycle to varying power requirements. As a result, the response to throttle commands is very sharp, and the engine develops large amounts of torque from only slightly above idling.
218d Active Tourer. The BMW 218d Active Tourer (fuel consumption urban/extra-urban/combined: 5.0/3.6/4.1 l/100 km [47/65/57.4 mpg US]; CO2 emissions combined: 109 g/km) is a four-cylinder diesel engine. A member of the same new engine family as its two gasoline counterparts, it delivers 110 kW/150 hp along with peak torque of 330 N·m (243 lb-ft). Acceleration from 0 to 100 km/h (62 mph) takes 8.9 seconds, and top speed is 205 km/h (127 mph).
225i Active Tourer. Topping the range at market launch is the four-cylinder BMW 225i Active Tourer (fuel consumption urban/extra-urban/combined: 7.6/5.0/6.0 l/100 km [31/47/39.2 mpg US]; CO2 emissions combined: 139 g/km). It features an output of 170 kW/231 hp, a 6.8-seconds 0 to 100 km/h (62 mph), and a top speed of 235 km/h (146 mph).
In the course of this year, a further three engine versions will join the BMW 2 Series Active Tourer range, along with intelligent BMW xDrive all- wheel-drive versions of one gasoline and one diesel model. By the end of the year the range will have been extended to include the BMW 220i, BMW 220d and BMW 216d, along with xDrive versions of the BMW 220d and 225i Active Tourer.
Chassis. The chassis has been newly developed from the ground up, with a wide track, reduced-friction steering system, a torsionally very stiff, lightweight body with short overhangs, a low vehicle centre of gravity and extensive aerodynamic measures, all of which help to give the new BMW handling qualities which are unique in this class. If the optional electronically controlled dampers are specified, the chassis characteristics can be adjusted to different driving situations with a choice of two different settings, making for improved ride comfort and driving dynamics.
The single-joint front spring-strut axle of the BMW 2 Series Active Tourer features lightweight, very stiff components and calibration of the suspension kinematics and elastokinematics for agile cornering performance, excellent directional control and largely torque-steer-free steering. Aluminium swivel bearings, use of high-strength steel in the axle subframe and wishbones and the hollow, variable-gauge anti-roll bar reduce unsprung masses and contribute to agility and ride comfort.
Overall, the suspension kinematics and spring/damper tuning ensure maximum lateral acceleration and directional stability. Meanwhile, optimized mountings and bearings and elastokinematics also maintain high standards of ride comfort. For example, the dampers both front and rear are decoupled from the body using a class-leading solution based on three-way support mounts.
With its high-strength steel construction, very stiff control arms and hollow anti-roll bar, multi-link rear axle complements the sporty front-wheel-drive set-up, while the separate springs and dampers have benefits for the space-efficient overall layout. The axle subframe provides an optimal connection between the multi-link axle and the body. Carefully calibrated components such as the wheel bearings or the ball-and-socket joints and rubber mounts on the wheel carriers optimize camber stiffness for improved stability.
The new BMW 2 Series Active Tourer’s electromechanical power steering system gives equal priority to both agility and comfort while also being largely free of torque steer. In order to preserve typical BMW steering characteristics in this front-wheel-drive model, the hardware and software have been matched to the new drive configuration. The servo unit and steering gear are combined in a single component, so that the steering assistance acts directly on the single pinion, resulting in very low friction.
The front axle has been designed to provide very direct steering response and to give precise feedback on load conditions and road surface. Torque steer has been reduced to a minimum by precisely calculated elastokinematics and precise software calibration, and engine forces are counteracted by optimally designed engine and transmission mounts and the engine pendulum mount. Finally, a very stiff vehicle front end makes a further contribution to steering precision.
Additional comfort can be provided if the optional Servotronic speed-sensitive power assist is specified, while the optional Variable Sports Steering goes a step further still in terms of agility and precision. By varying the steering ratio depending on the steering angle, Variable Sports Steering reduces the steering effort required during parking and turning maneuvers, while at higher speeds providing high standards of straightline stability and track-holding, with very precise directional control.
Drivers of the BMW 2 Series Active Tourer are assisted by a range of electronic chassis control systems geared to improving both active safety and driving dynamics. The DSC (Dynamic Stability Control) system comprises ABS, DTC (Dynamic Traction Control), EDLC (Electronic Differential Lock Control) and Performance Control, along with a number of front-wheel-drive-adapted subfunctions, including a torque interface,
The driving dynamics of the new BMW 2 Series Active Tourer are also influenced by the weight of the vehicle and the stiffness of the body. High-tensile and ultra-high-tensile multi-phase steels and use of tailored blanks help to create a body which combines strength with low weight. The hood, meanwhile, is made of lightweight aluminium and weighs just 8 kg (17.6 lbs), 50% less than a conventionally produced component. The bumper supports, steering shaft, brake guards and wheel swivel bearings likewise help to reduce weight.
The new BMW 218i Active Tourer has a drag coefficient of cd = 0.26. The overall proportions, the vehicle front and rear end and the largely smooth-surfaced underbody panelling have all been aerodynamically optimized. At the same time, BMW Air Curtain technology at the front apron produces a curtain of air in front of the wheel arches to reduce turbulence at the front wheels.
The roof spoiler is integrated with the D-pillar trailing edges (aeroblades) to form a single component which optimizes rear-end airflow. The trailing edges of the rear lights are a further drag-reducing feature. Finally, active control of the air flaps behind the BMW kidney grille and in the lower cooling air intake makes a further contribution to the cd value and low fuel consumption of the BMW 2 Series Active Tourer.
Connectivity. BMW ConnectedDrive technologies include the Traffic Jam Assistant and the camera-based cruise control system with Stop & Go function, which both work using a mono camera. They assist with accelerating and braking (longitudinal guidance) as well as steering (lateral guidance with the Traffic Jam Assistant), at the same time as relieving the driver of monotonous tasks, such as when driving in a queue of traffic on the highway or in heavy city-center traffic.
BMW ConnectedDrive Services & Apps bring smartphone applications into the vehicle and allow features such as the Concierge Service or Real Time Traffic Information to be added.
The BMW 2 Series Active Tourer is the first model in the premium compact class to be made available with a Head-Up Display, which projects all relevant driving information into the driver’s field of vision in full color. Instead of being displayed on the windscreen itself, the information is shown on a screen that extends out between the steering wheel and windscreen. This enables drivers to view all key information without having to divert their attention from the road.
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