about thirty of the appearance of the BMW 325i Allrad (E30) at the iaa in Frankfurt. For the first time
the manufacturer had a model of awd, marking a milestone that
arrives to our days with the xDrive. By then the awd was a real exoticism in cars that were not suvs.
That first model
had a technology a little rudimentary: a differential
viscous coupling which delivered a 37% torque to the front wheels
and the rest to the rear. Not only improved the behavior of the 325i
in conditions of low adhesion, also in sporty driving.
commercial name happened to be 325iX, and in 1988 he was available
also the family version (Touring) with the same engine. Not available
an electronic control, the difference of speeds of rotation of the
axis provided the distribution of torque. It was like having a union almost rigid axle.
In 1991
it appears the BMW 525iX, this time with an electronic control of the distribution of
pair. The differential viscous gave way to a differential
multiembragues, first driven hydraulically and after
electronically using brakes.
BMW has always wanted a distribution more rear to not fit in with the rest of models
The distribution of force
by default it was 36:64, although it could vary in function of the
conditions. As in the 3 Series above, the option was available
both the sedan body to the family.
sensors of the ABS to detect differences in rotation speed between the
different wheels. In addition, the electronic control unit I had in mind
other information, such as the speed of rotation of the motor, position of the
accelerator pedal, or information from the braking system.
In
1999 appears the first generation of the BMW X5, starting the season in the
that this brand is dedicated to the manufacture of todocaminos, saga X.
Again I had a different system, a planetary gear passing
38% of power to the front wheels in normal conditions.
New
electronic aids came into play, as the DSC control
stability), or the HDC (assistant to the descent control). BMW does not
it was intended that the X5 was an suv, had already been raised as a
“Sports Activity Vehicle” or SAV, the way in which BMW refers to the SUV.
The 2000 3 Series (E46) again benefited from all-wheel-drive, after
absence in the previous generation (E36). Soon after that came an SUV
smaller, the BMW X3, which also benefited from the all-wheel drive
in all its variants, as happened with the X5.
The
X3 he brought under his arm a updated version of the system xDrive. The
DSC system added additional information to the calculation of distribution of torque,
including the angle of rotation of the steering wheel or the lateral acceleration. The
aim was to improve the motor skills, not the skills out
of the road.
Shortly before 2010 they had sold a
million BMW X5, and 600,000 X3. Both todocaminos occur outside of
Germany, in Spartanburg (united States). Thus, little by little, the traction
total xDrive has come to 12 models of the range, with a total of 110 variants. There are even versions with all-wheel-drive power, that is to say,
one of the axes is moved by electric motors.
Today
BMW has two fundamental types of models, front-wheel-drive or
propulsion in the rear, in both cases it is possible to choice of traction
total depending on the engine. Interestingly, for market reasons, BMW also began to sell versions 4×2 of their SUV, the sDrive. The tortilla is
gave the back.
–