The document discusses steering gear ratios, which indicate the relationship between the rotation of the steering wheel and the turning of the wheels. It states that heavy vehicles have a ratio of 20:1, meaning the steering wheel must rotate 20 degrees for the wheels to turn 1 degree, while cars have a ratio of 12:1. With heavy vehicles turning their wheels 60-80 degrees, this corresponds to the steering wheel rotating 1200-1600 degrees, or 3-4 full revolutions. It also briefly mentions different types of steering gears like rack and pinion and worm and nut systems.