BMW 5 - Manual (Page 34)

BMW
Media
Information
11/2009
Page 34
Reduction of friction losses is an overriding objective pursued consistently
on all engine units and ancillaries. Use of a special light transmission fluid in
conjunction with a reduced amount of fluid in the final drive cuts back both
friction and oil splash losses immediately after setting out.
Like the new BMW 7 Series, the new BMW 5 Series Sedan also comes
with its final drive in aluminium, warming up more quickly and reducing
thermal loads at high speeds.
The reduction of air resistance also serves to cut back fuel consumption.
As a result, all versions of the new BMW 5 Series Sedan with the exception
of the BMW 550i come with active cooling air flaps opening or closing
specifically according to current driving conditions. This further improves the
aerodynamic qualities of the car whenever the demand for cooling air remains
at a low level, just as the extra-smooth underfloor promotes the flow of air
beneath the vehicle.
Efficient power transmission: manual gearbox with dry sump
lubrication and eight-speed automatic transmission.
The new BMW 5 Series Sedan features a new generation of six-speed
manual gearboxes and, as an option (standard in the BMW 550i), an
eight-speed automatic transmission.
All transmissions stand out through an even higher degree of efficiency,
compact dimensions and low weight. The new manual gearbox on the
BMW 535i, the BMW 525d and the BMW 520d comes with dry sump
lubrication and a modified gearset concept for even greater gearshift
comfort and even lower drag losses within the gearset. Fully controlled oil
supply serves furthermore to avoid oil splash losses otherwise suffered in
the process of distributing large amounts of oil.
The eight-speed automatic transmission also complies in full with the
principles of BMW EfficientDynamics, likewise featuring innovative gearset
configuration with additional gears and a larger spread of increments versus
the former six-speed automatic transmission without any negative effects in
terms of size, weight, and the inner efficiency of the system. Shifting gears
very quickly and providing direct access to the target gear lane when shifting
back for maximum acceleration, the eight-speed automatic transmission
gives the new sedan even greater driving dynamics and performance. At the
same time converter slip restricted to the setting-off process and reduced
to a minimum even under such conditions, the high degree of inner efficiency,
low frictional losses with only two clutches open at a time, longer transmission
ratios in higher gears and transmission management for driving smoothly at