What is bar underneath car?

A bar underneath a car is also known as a sway bar or anti-roll bar. It is a suspension component that helps to reduce body roll and improve handling during cornering by transmitting forces between the left and right wheels. The sway bar works by connecting both sides of the suspension together with a torsion spring, allowing the suspension on one side to compress and transfer its energy to the opposite side when cornering. This helps to keep the car level, increase traction and stability, and prevent excessive weight transfer when turning. The sway bar is typically made of steel or other durable materials and may be adjustable for varying driving conditions or preferences.