Advanced Automotive Technology: Visions of a Super-Efficient Family Car

cars, hence unacceptable to consumers as trucks. GM’s highly aerodynamic Lumina Van has not
been popular with customers, partly because the sharp nose made it difficult to park; the Lumina
Van was recently redesigned and its CD was increased from the previous value of 0.32.

Manufacturer’s projections of potential improvements in future truck CD are given in table 3-4.

Effect of Advanced Aerodynamics on Vehicle Prices

The costs of aerodynamic improvements are associated primarily with the expense of
developing a low drag body shape that is attractive and then developing the trim and aerodynamic
detailing to lower CD. The essential inseparability of drag reduction and styling costs makes it
difficult to allocate the fixed costs to aerodynamics alone. Manufacturers confirmed that current
body assembly procedures and existing tolerances were adequate to manufacture vehicles with
CD levels of 0.25 or less.

Previously, aerodynamic styling to CD levels of 0.30 required investments in the range of $15
million in development costs.^36 Requiring levels of CD to be less than 0.25 would likely double
development costs owing to the need to stabilize underbody airflow and control engine and
internal air flow. Unit variable costs to an automobile manufacturer (from supplier data) are:

l

l

l

Flush glass windows: $8 to $10 (for four),

Underbody cover (plastic): $25 to $30,

Wheel skirts: $5 to $6 each.

Hence the retail price effect (RPE) is calculated as follows:

l

l

l

Unit investment cost: ~$30,

Variable costs: ~$48 to $64,

RPE: ~$125 to $150.

These RPE’s would be associated with CD levels of 0.20 to 0.22, while RPE for achieving a

CD levels of 0.24 to 0.25 would not require wheel skirts, reducing theRPEto$90to$115.

Price effects for trucks are expected to be similar to autos, for a similar percentage reduction in
drag. Of course, the absolute values of CD will be higher.

(^36) Energy and Environmental Analysis, Inc., Documentation of the Fuel Economy Performance and Price impact of Automotive Technology,
prepared for Oak Ridge National Laboratory, Martin Marietta Energy Systems, July 1994.