A four-wheel vehicle is provided with an in-wheel motor in each of a front
wheel and a rear wheel and has approximately the same roll center heights
of the front wheel and the rear wheel. The relation between a change in a
kingpin offset and a change in a wheel stroke for at least any one of the
front wheel and the rear wheel of the four-wheel vehicle is determined
based on at least any one of braking force distribution and driving force
distribution between the front wheel and the rear wheel.