The impact performance of a vehicle chassis is critical for safety and durability, influenced significantly by the materials used. Two common materials are AISI 4130 and AISI 1018, each with distinct properties affecting their impact resistance. AISI 4130, a chromium-molybdenum steel, is known for its high strength and toughness, providing excellent resistance to deformation and cracking. This makes it ideal for high-performance vehicles where impact resistance is crucial. However, its increased weight can be a drawback in some applications. Conversely, AISI 1018 is a low-carbon steel offering a balance of strength, ductility, and formability. It is lighter and more easily formed into complex shapes, making it a cost-effective choice for many applications. Despite its lower strength compared to AISI 4130, it is suitable for scenarios where weight and cost are more critical. Choosing between AISI 4130 and AISI 1018 depends on specific application needs. For high impact resistance and performance, AISI 4130 is preferred. For weight-sensitive and cost-efficient applications, AISI 1018 is more suitable. The decision requires careful consideration of material properties, application requirements, and design constraints. Key Words: AISI 4130, AISI 1018, Chromium Molybdenum Steel, Low Carbon Steel, Impact Resistance.