This paper describes a debate about national fuel-economy standards for sport-utility vehicles (SUVs) used as a foundation for exploring a public policy issue in the physical science classroom. The subject of automobile fuel economy benefits from a familiarity with thermodynamics, specifically heat engines, and is therefore applicable to a broad range of courses found in the disciplines of physics, chemistry, and engineering. This topic could also be discussed, with somewhat less technical sophistication, in a physical science course for nonscience majors. (Contains 3 tables and 2 figures.)