What material is primarily used in modern unibody construction for its lightweight properties?

In modern unibody construction, steel is primarily used due to its combination of lightweight properties, strength, and cost-effectiveness. While aluminum has gained popularity in automotive construction for its lightweight nature, steel remains a staple material because it provides structural integrity and safety features necessary for vehicle performance.

Steel's ability to be formed into complex shapes allows for the integration of various components within the vehicle structure, contributing to the overall rigidity and safety of the unibody design. Additionally, advancements in high-strength steel technologies have made it possible to create thinner, lighter components without compromising safety, further supporting its continued dominance in this area of automotive manufacturing.

While fiberglass and plastic are utilized in certain vehicle parts due to their lightweight characteristics, they typically do not provide the necessary strength and crash-worthy features required for the main structural components of a unibody vehicle.