Worn tires should be replaced primarily to ensure:

Worn tires should be replaced primarily to ensure improved traction and safety. As tires wear down, the tread depth decreases, which significantly affects their ability to grip the road. This reduction in traction can lead to challenges in braking, handling, and maneuvering the vehicle, particularly in adverse weather conditions such as rain or snow. Adequate tire tread is essential for maintaining control of the vehicle and preventing accidents, making safety the foremost reason for replacing worn tires.

While better fuel economy, enhanced comfort during rides, and a longer tire lifespan are also considerations when it comes to tires, they do not primarily address the critical issues of traction and safety that worn tires pose. Ensuring that tires are in good condition directly influences the vehicle's performance and the safety of its occupants.