Lightweight, crash-sensitive automotive component

A method of making a vehicle with a crash-sensitive automotive component having a desired performance during collision, the performance measured using critical fracture strain, the method comprising:

• obtaining a crash-sensitive automotive component that was produced using a process including:
• providing a melt having an alloy comprising:
• about 6.0 wt % to about 7.8 wt % Si:
• about 0.10 wt % to about 0.18 wt % Mg;
• less than or equal to about 0.35 wt % Cu;
• less than or equal to about 0.6 wt % Mn;
• less than or equal to about 0.15 wt % Fe;
• and, a balance of aluminum and impurities;
• casting the melt into a cast body of the crash-sensitive automotive component;
• and.
• heat treating the cast body, the heat treating including a solution heating at 450° C. to 550° C. for about ½ hour to about 6 hours;
• quenching, and aging at a temperature of about 150° C. to about 250° C. for about ½ hour to about 10 hours;
• and,
• employing the crash-sensitive component in the vehicle.

An aluminum alloy casting having a desired critical fracture strain, the casting comprising:

• about 6.0 wt % to about 7.8 wt % Si;
• about 0.10 wt % to about 0.18 wt % Mg;
• less than or equal to about 0.35 wt % Cu;
• less than or equal to about 0.6 wt % Mn;
• less than or equal to about 0.15 wt % Fe,
• and, a balance of aluminum and impurities;
• the casting produced using a process that includes a solution heating at 450° C. to 550° C. for about ½ hour to about 6 hours, quenching, and aging at a temperature of about 150° C. to about 250° C. for about ½ hour to about 10 hours.