Vehicle Design

Vehicle Efficiency

Due to government regulations, societal influences, and increasing competition there is an increased effort to improve vehicle fuel economy and emissions.  Only about 15% of the energy in the fuel you put in your gas tank gets used to move your car down the road with a typical internal combustion engine, while the rest of the energy is lost.  Because of this the potential to improve fuel economy with advanced technologies is enormous. 

Paths of energy through a typical gasoline-powered vehicle in city driving

The 12.6% of original fuel energy that makes it to the wheels must provide acceleration (5.8%) and overcome aerodynamic drag (2.6%) and rolling resistance.  In a highway driving environment, aerodynamic drag, which increases at an increasing rate with speed requires the most energy (about 10.9%).  The potential for improvements in fuel efficiency as a result of the design process include reducing vehicle drag, reducing vehicle mass, and then improving powertrain efficiency with new technologies.