What is the purpose of a sway bar in a vehicle’s suspension?

The primary purpose of a sway bar, also known as an anti-roll bar or stabilizer bar, is to reduce body roll during cornering. When a vehicle turns, centrifugal force causes the body to lean to the outside of the turn. This body roll can affect vehicle handling and stability. The sway bar works by connecting the left and right sides of the suspension, providing resistance against this leaning motion. As one side of the vehicle's suspension compresses during a turn, the sway bar transfers some of that movement to the opposite side, helping keep both sides more level. This results in improved traction and stability while cornering, enhancing overall vehicle handling.

While other options such as improving fuel efficiency or stabilizing the vehicle at high speeds may be desirable characteristics of a well-balanced vehicle, they are not direct functions of a sway bar. Similarly, a sway bar does not play a significant role in braking performance. Its main function is clearly related to managing body roll and maintaining better control during turns.