* Heavier Weight: Larger cars weighed significantly more than smaller ones. This increased the force needed to turn the wheels. A larger diameter steering wheel provided mechanical advantage, increasing the leverage available to the driver to overcome this resistance.
* Larger Wheels and Tires: Bigger cars often had larger diameter wheels and tires, further increasing the rolling resistance and thus the effort required to turn.
* Heavier Steering Components: The entire steering system (including the steering column, linkage, and gear) was typically heavier and more robust in larger cars, again adding to the turning effort.
* Steering Gear Ratio: While gear ratios could be modified, a higher ratio (more turns of the steering wheel for a given turn of the wheels) was sometimes necessary for better steering feel and responsiveness in larger vehicles, further increasing the effort required.
In essence, the larger steering wheel acted as a force multiplier, making it physically possible for a human to turn the wheels of a heavy vehicle. Without it, the effort would have been excessive and impractical.
