Search

This is an article that offers answers to questions sent in by readers. Why is the fuel economy of a car better in the summer? Harold Schock, professor of mechanical engineering and director of the Automotive Research Experiment Station at Michigan State University, explains:. In cold, snowy weather, the fuel economy during trips of less than 10 minutes in urban stop-and-go traffic can easily be 50 percent lower than during operation of the same vehicle in light traffic with warm weather and dry roads. The aerodynamic drag acting on a vehicle increases in colder weather as well.Air density is 17 percent lower on a hot, 80degree day than it is on a cold, zero-degree day. Why does inhaling helium make one's voice sound strange? The culprit is the difference between the density of the helium in one's larynx and that of the nitrogen and oxygen that make up most of the air a person normally breathes.