This presentation outlines practical ways that Class-8 truck fleets can realize significant fuel savings and increased profits through efficiency techniques. Focusing on components that save fuel and providing case studies that have capitalized on these opportunities, RMI’s researchers demonstrate how a 25% fuel economy improvement is possible using existing technologies that can be retrofitted onto almost any highway truck. Because trucking accounts for 19.4 percent of U.S. transportation GHG emissions, the trucking industry has a significant impact on global climate change. However, cutting GHGs can present a business advantage because cutting emissions also leads to cut costs. It can also provide a marketing advantage to companies. Profitable strategies presented include aerodynamics and rolling resistance,tires, APU’s, and hybrids. Fleets that have successfully utilized these changes are outlined to show that the potential profits are substantial. Other unexpected benefits are also available by applying whole-systems thinking to trucks.