EGEE102:Energy Conservation and Envrionmental Protection

 

3.8 Overall Efficiency

A similar analysis on automobile efficiency is shown in the Figure below.

The table below shows that only about 10% of the energy in the crude oil in the ground is in fact turned into mechanical energy moving people.

Overall Efficiency of an Automobile:

Step Step Efficiency Cumulative Efficiency
or Overall Efficiency
Production of Crude 96% 96%
Refining 87% 84%
Transportation 97% 81%
Engine 25% 20%
Transmission 50% 10%