Problem Graphic

Andy, the manager of EZ Trucking, would like to convince his boss to invest in installing air deflectors on their 18-wheelers. Research has shown that the drag coefficient, C_D, is lower for an 18-wheeler with an air deflector (from 0.95 to 0.75). How can he show that the air deflector will save the company a small fortune?

What is the drag exerted on the 18-wheeler with and without the air deflector?

• The drag force is directly proportional to the fuel consumption.
• Base the analysis on a frontal area, A, of 100 ft².
• Assume the 18-wheeler runs at an average speed of 65 mph on the highway.