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

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the technical “context” that made the technology attractive or unattractive--the prevalent fuel or the

nature of the technologies affecting or affected by the technology--may change;

new regulations (for example, emission standards not easily complied with by the technology) can either

hinder or enhance technology introduction;

manufacturing the technology in large quantities can turn out to be more difficult and expensive than

was expected, or improvements in manufacturing can do the reverse;

problems may occur in the “real world” operating environment that are difficult to overcome (some

automotive technologies fail because they require levels of maintenance that are difficult to get U.S. car

owners to comply with, or because driving patterns place more severe strains on performance than were

originally forecast by test results).

Moreover, when technologies enter the marketplace, their effect on vehicle performance may be
considerably different from projected levels because of unforeseen changes in measured
performance as the technology moves from the laboratory bench to prototype to production
model. These changes may come from physical scaling effects that were not widely understood at
the time of the forecast; from the need to change design to deal with an emerging problem; or
even from design changes that deliberately trade off one performance characteristic against
another (for example, sacrificing efficiency to achieve lower cost, or vice versa).

Forecasts also may go astray because of incorrect methodology--for example, not accounting

for costs such as dealer markups and transportation costs (or not accounting for cost savings)--or

simply by the acceptance of exaggerated claims (positive or negative) from sources with a

financial or ideological stake in the technology or one of its competitors.

Considering the limitations of technology forecasting, OTA’s forecast is meant to serve a

limited purpose:

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to gain a rough estimate of the magnitude of fuel economy improvement potential over the next 20 years;

to identify future policy challenges associated with advanced vehicles, such as potential for higher costs,

difficult market challenges, potential safety problems; and

to provide assistance in evaluating existing and proposed vehicle research programs.

ENERGY USE AND REDUCTION IN LIGHT-DUTY VEHICLES

Vehicles use energy primarily to produce power at the wheels to overcome three tractive forces

that would otherwise prevent the vehicle from moving: aerodynamic drag forces, the force of air

fiction on the body surfaces of the vehicle; rolling resistance, the resistive forces between the

tires and the road; and inertial force, the resistance of any mass to

vehicle is climbing a grade, its mass exerts a downward restraining

must produce energy to power accessories such as heating fan, air

acceleration. Moreover, if the

force. In addition, the vehicle

conditioner, lights, radio, and