In the automotive industry, alloy wheels are wheels that are made
from an alloy of aluminium or magnesium. Alloys are mixtures of a
metal and other elements. They generally provide greater strength
over pure metals, which are usually much softer and more ductile.
Alloys of aluminium or magnesium are typically lighter for the same
strength, provide better heat conduction, and often produce
improved cosmetic appearance over steel wheels. Although steel, the
most common material used in wheel production, is an alloy of iron
and carbon, the term "alloy wheel" is usually reserved for wheels
made from nonferrous alloys.