|2.0-Liter BMW Twin Power Turbo gasoline engine. Click to enlarge.|
Simultaneously with the market launch of the new BMW X1 xDrive28i, BMW is introducing the first four-cylinder representative of its Efficient Dynamics engine family.
The 2-liter unit is equipped for the first time with BMW TwinPower Turbo technology that is already employed on the in-line six-cylinder power unit. (Earlier post.) The engine’s technology package comprises a supercharging concept according to the Twin Scroll principle, direct gasoline injection, double VANOS variable camshaft control and VALVETRONIC variable valve control.
Efficient Dynamics engines. The new BMW Efficient Dynamics family of engines uses a standardized set of design principles and a significantly increased number of common components for both gasoline and diesel engines. The new BMW modular engine system is based upon the in-line engine principle as well as on the BMW TwinPower Turbo technology package.
The new BMW modular engine system allows three, four and six-cylinder power units to be developed, with various power outputs. This scalability lays the groundwork for a broad performance spectrum and thus for diverse, worldwide application in vehicle concepts within the BMW Group.
These gasoline and diesel engines of the future with three, four and six cylinders will be manufactured with a maximum degree of flexibility at the BMW facilities in Munich and Steyr. By 2012, the BMW Group will have invested almost €300 million (US$427 million) in both production locations.
New 4-cylinder gasoline direct injection engine. The newly designed engine for the BMW X1 xDrive28i delivers 180 kW/245 bhp—55 kW more than BMW’s previously most powerful four-cylinder combustion engine. Maximum torque of 350 N·m (258 lb-ft) is available at an engine speed of 1,250 rpm. With this output, the new BMW TwinPower Turbo power unit surpasses a BMW six-cylinder aspirated engine in terms of response and pulling power.
The increase in dynamics is accompanied by a significant reduction in fuel consumption and emission levels. The car accelerates from 0 to 100 km/h in 6.5 seconds, 0.3 seconds faster than the predecessor model also featuring an automatic transmission. Average consumption is down by 1.5 liters to 7.9 liters/100 km (30 mpg US).
The new four-cylinder engine features extensive work on the basic engine. Vertically offset balance shafts effectuate optimized vibration compensation. In addition, a centrifugal force pendulum integrated into the dual-mass flywheel ensures a noticeable reduction in irregular rotations usually occurring within the lower engine speed range. Thus, the engine’s early high torque output can be utilized without any loss in comfort.
The optimum vibration damping achieved through the centrifugal force pendulum remains effective across a broad engine speed range. Hence, the new 2-liter engine advances to a level of running smoothness that was previously only achievable with six-cylinder engines.
New 3-liter diesel. With the further development of BMW TwinPower Turbo technology, additional dynamics and efficiency potentials have also been made accessible for use on in-line six-cylinder diesel engines. The new 3-liter diesel power unit features a further optimization of internal friction coefficients, weight and fuel injection.
Maximum power output has been increased by 10 kW to 190 kW/258 bhp. Maximum torque is now 560 N·m (413 lb-ft)—20 N·m more—and is available at 1,500 rpm.
Apart from modified air supply with shortened ducts, the response characteristics of the new six-cylinder diesel engine also benefits from a weight-optimized crankshaft.
An optimized injection process contributes additionally towards an increase in output and torque. Common Rail injection, the solenoid valve injectors of which operate at a maximum pressure of 1,800 bar, ensures, inter alia, by means of a recalibrated pre-injection system even more efficient combustion, spontaneous power development and enhanced acoustic characteristics of the diesel engine.
The turbocharger with variable intake geometry has been further optimized and now boasts even better stability. Simultaneously, the weight of the turbine wheel was reduced. The spontaneous response of the supercharger associated with this boosts power delivery at low engine speeds.
The new diesel engine featured in the new BMW 530d xDrive facilitates acceleration from 0 to 100 km/h in 6.1 seconds. Average fuel consumption in the EU test cycle is 5.7 liters/100 km (41 mpg US), while the CO2 emission level has been reduced to 150 grams per kilometer.
In terms of its basic constructional features, including the arrangement of the ancillary components and the belt drive, the new in-line six-cylinder is virtually identical to the current BMW four-cylinder diesel power units.
Eight-speed automatic transmission with anticipatory transmission control system. The transmission technology featured in current models also contributes towards the efficiency of BMW automobiles. The new eight-speed transmission features an innovative gear set configuration that permits the combination of additional drive positions and a greater transmission ratio spread with a compact design and optimized weight.
Compared to the previously employed six-speed automatic transmission, the new gearbox features two additional gears and a transmission ratio spread that has been increased from six to seven, while the number of gear sets has been increased by just one to a total of four, the number of clutches even remaining the same. With the low number of additional components, the system’s internal efficiency is optimized.
In addition, the eight-speed automatic transmission, which is now with four, six, eight and twelve-cylinder engines, is characterized by particularly high shifting dynamics and direct gear selection. The electronic control of the transmission facilitates varying control maps for shifting characteristics, with which either an exceptionally dynamic or a comfort-oriented driving style is achieved.