At a given motor's output, top speed and acceleration are determined by the gear ratio. In comparison, between a gear ratio and a gear ratio, the smaller ratio is more suitable for speed oriented circuits, while the bigger produces more acceleration.
Wide Tires Wide Tires: Provide stability during cornering. Good for technical courses with banking curves and ups and downs. Narrow Tires: Good for long straights. Less drag on the motor, which may give the advantage of longer run times.