per pound than ordinary carbon steel, but 10 percent less is required to make a part, so, on a part
basis, the two have roughly equivalent cost.Manufacturing costs
As with any mass production industry, cost containment/reduction (while maintaining
equivalent performance) is a dominant feature of the materials selection process for automotive
components. Customarily, this objective has focused the automobile designer upon a search for
one-to-one substitutes for a particular part, where a material alternative can provide the same
performance for lower cost. More recently, the focus has broadened to include subassembly costs,
rather than component costs, which has enabled consideration of materials that are initially more
expensive, but may yield cost savings during joining and assembly. Manufacturers can also reduce
costs by shilling production of complex subassemblies (such as dashboards, bumpers, or door
mechanisms) to suppliers who can use less expensive labor (i.e., non-United Auto Worker labor)
to fabricate components that are then shipped to assembly plants.Thus, the manufacturer’s calculation of the cost of making a materials change also depends on
such factors as tooling costs, manufacturing rates, production volumes, potential for consolidation
of parts, scrap rates, and so forth. For example, the competition between steel and plastics is
discussed not only in terms of the number of units processed, but also the time period over which
these parts will be made. Because the tooling and equipment costs for plastic parts are less than
those for steel parts, low vehicle production volumes (50,000 per year or less) and short product
lifetimes lead to part costs that favor plastics, while large production runs and long product
lifetimes favor steel. As automakers seek to increase product diversity, rapid product development
cycles and frequent styling changes have become associated with plastic materials, although the
steel industry has fought this generalization. Nevertheless, styling elements like fascias and
spoilers are predominantly plastic, and these elements are among the first ones redesigned during
product facelifts and updates.
Life Cycle Costs
The total cost of a material over its entire life cycle (i.e., manufacturing costs, costs incurred by
customers after the vehicle leaves the assembly plant, and recycling costs) may also be a factor in
materials choices. For example, a material that has a higher first cost may be acceptable, if it
results in savings over the life of the vehicle through increased fuel economy, lower repair
expense, and so forth. However, this opportunity is rather limited. For instance, at gasoline prices
of $1.20 per gallon, fuel cost savings owing to extensive substitution of a lightweight material
such as aluminum might be $580 over 100,000 miles of driving--about $1 per pound of weight
saved. These savings are insufficient to justify the added first cost of the aluminum-intensive
vehicle (perhaps as much as $1,500, see below). Moreover, manufacturers are generally skeptical
about the extent to which customers take life cycle costs into consideration in making purchasing
decisions.Materials choices also influence the cost of recycling or disposing of the vehicle, though these
costs are not currently borne by either the manufacturer or consumer. This situation could change