I have a few questions regarding slip differentials for wheeled robots. I plan to use a motor to drive the rear wheels of my robot, which are connected via a rod. Because the wheels are connected by a rod, their rotational velocity would be the same and that would cause poor performance when turning. At least that's how it is with cars, however since my robot is only 5 to 10 percent of an automobile in terms of size, I'm wondering if it would require slip differential gears. I have considered using two motors, one for each rear wheel but that would drive up cost and weight. What are your thoughts on that? Any suggestions will be greatly appreciated.