Según un catálogo de Volvo, el comportamiento de la tracción integral es el siguiente:
"NORMAL DRIVING
During normal driving on a dry surface, nearly all tractive force goes to the
front wheels ( 95%).
ACCELERATION
During acceleration, the AWD system distributes engine power between
the front and rear wheels so that the greatest amount of power is
transferred to the ground and can be utilised to propel the car forward.
Thus, the AWD system contributes to the car's good acceleration capacity,
particularly on rough surfaces.
ELECTRICALLY CONTROLLED HYDRAULIC COUPLING
Engine power is distributed automatically between the front and rear pairs
of wheels with the help of an electronically regulated, hydraulic coupling.
This new type of hydraulic coupling reacts very quickly and can transfer full
torque before the wheels have even turned much. This quick reaction
reduces the risk of the front wheels digging down into e.g. loose sand.
INTELLIGENT AWD
The Volvo XC90 has been developed with permanent drive to all four
wheels. Tractive force is automatically distributed between the front and
rear wheels. This is regulated electronically, and is affected by the road
surface and driving style.
QUICK AND SMOOTH REACTIONS - ALL-WHEEL DRIVE
Tractive force is automatically distributed between the front and rear wheels.
This is regulated electronically, and is affected by the road
surface and driving style.
IF THE FRONT WHEELS SPIN
If the road surface is such that the front wheels begin to spin, more
tractive force is distributed proportionately to the rear wheels. This
redistribution of force takes place very quickly, without the driver being
aware of it.
INTELLIGENT AWD
The Volvo XC90 has been developed with permanent drive to all four
wheels. Tractive force is automatically distributed between the front and
rear wheels. This is regulated electronically, and is affected by the road
surface and driving style.
TRACS
Distribution of power between wheels on the same axle is controlled by the
anti-spin system TRACS. If one of the wheels begins to spin, TRACS ensures
that power is transferred to the other wheel on the same axle. This
contributes to the best possible starting and driving characteristics,
particularly on slippery surfaces."
Es decir, como mínimo reparte un 95% de la tracción a las ruedas delanteras, y a partir de ahí la distribuye a las traseras a medida que se incrementa la aceleración o se producen pérdidas de tracción en el eje delantero.
