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Suzuki's First Fulltime 4-Mode 4x4 System with Centre Differential
New Grand Vitara Achieves Off-Road Performance
Unprecedented in a Compact SUV |
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Suzuki's new Grand Vitara, third generation of the renowned compact SUV that debuted in 1988, offers enhanced performance for both on- and off-road driving. Suzuki engineers succeeded in giving the new model outstanding rough-road driveability in a sophisticated package that is remarkably comfortable on city streets and motorways.
The engineers replaced the previous mol's part-time 4x4 system with a newly developed fulltime 4-mode 4x4 system featuring a torque-sensing, limited-slip-differential (LSD) at the centre. This fulltime system, a first for Suzuki vehicles, remains continually engaged throughout driving in four traction modes' 4H, 4H Lock, 4L Lock, and N' that the driver can match to any running situation. The cam-type LSD controls differential function to prevent skidding when a wheel slips, by maintaining torque on another wheel. And the torque-sensing LSD optimizes torque distribution between front and rear wheels in accordance with the driverÕs acceleration pedal input for greater response. Furthermore, the centre differential features a lock mechanism to directly connect the front and rear propeller shafts, enabling required torque on other wheels if some wheels are slipping.
In the 4H (high-range 4x4) mode, the centre LSD absorbs differences between front and rear wheel speeds and keeps the front/rear torque split at 47:53, realizing smooth, quiet performance and neutral cornering during on-road driving, like conventional 4x2s. On the other hand, the 4H mode delivers superb off-road traction when the Grand Vitara tackles rough terrain.
Under demand for more traction power, the 4H Lock mode delivers ample torque to front wheels even if rear wheels are slipping, helping the Grand Vitara to escape out of deep snow or mud. Eliminating any speed differences between front and rear wheels contributes to reduce the 'tight cornering braking effect' which tends to occur with non-centre-differential 4x4 systems because of front/rear speed differences when differentials are locked.
Facing even tougher terrain conditions, the 4L (low-range 4x4) Lock mode transmits power via high-low transfer, offering sufficient low-end traction to drive over bumps.
And in the unlikely event that the Grand Vitara needs to be towed, the N (neutral) mode keeps the centre differential free from potential wear and tear.
The four modes are easily selected on the road using a dial handily positioned on the instrument panel. Yet a built-in safety feature prevents failure by requiring deliberate pressure on the dial when transferring to N or 4L Lock modes. |
