 The VTM-4 system claimed to be different from other all-wheel-drive systems in that it "anticipated" wheel slippage, rather than waiting for the vehicle to sense wheel slippage, after the vehicle may already be in trouble.The VTM-4 system
consisted of a pair of computer-controlled wet clutches in the rear axle that worked in concert with the front wheels regardless of road conditions.On start-up, the VTM-4 system would send torque (power) from the front wheels to the rear wheels to supplement the normal front-wheel drive mode.