Patent ID: 7374255

Claim:
A control method for a four-wheel drive vehicle having main drive wheels connected to a driving power source, auxiliary drive wheels adjustable in drive torque, and a speed increasing mechanism switchable between a same speed condition and an increasing speed condition of said auxiliary drive wheels with respect to said main drive wheels, wherein said speed increasing mechanism is switchable to said increasing speed condition according to a running condition of said vehicle, said control method comprising the steps of: detecting a braking operation; detecting an accelerator opening or throttle opening greater than or equal to a predetermined value; maintaining said speed increasing mechanism in said increasing speed condition when said detected accelerator opening or throttle opening is greater than or equal to said predetermined value simultaneously with the detection of said braking operation, and switching said speed increasing mechanism to said same speed condition when said detected accelerator opening or throttle opening is less than said predetermined value simultaneously with the detection of the braking operation.