ASE Suspension and Steering (A4) Practice Test 2025 - Free ASE A4 Practice Questions and Review Guide

The primary function of a sway bar, also known as a stabilizer bar, in a vehicle's suspension system is to reduce body roll during cornering. When a vehicle turns, centrifugal force causes the body to lean towards the outside of the turn. The sway bar connects the left and right sides of the suspension, helping to distribute the load more evenly across both sides. This counteracts the natural tendency of the vehicle to roll, allowing for better stability, handling, and safety during turns.

The design of the sway bar enables it to twist and provide resistance to body roll. By reducing this roll, the sway bar enhances the driver's control and maintains tire contact with the road, thus improving overall cornering performance. This is especially important in vehicles that are driven with a sporty demeanor or that carry a heavier load.

In contrast, while ride comfort is influenced by other components of the suspension system, the sway bar's main role focuses specifically on managing body roll. Traction enhancement is typically managed by other aspects of the suspension and the tires, and the longevity of shock absorbers is not a direct function of the sway bar itself but rather relates to the overall configuration and treatment of the suspension system.