– Wal-Mart, which operates one of the largest private fleets in the world, has made a commitment to reduce its greenhouse-gas emissions by 25 percent and to double new truck efficiency by 2015. Those fuel-efficiency innovations could keep 26 billion lbs. of carbon dioxide out of the air between now and 2020, according to the company’s Web site.
Several changes to the physical dieselpowered trucks in the 2007-generation will make a big difference, according to Walmartstores.com. Improvements include: Making the tractor more aerodynamic reduces the fuel required to operate the truck, as approximately two-thirds of all gallons burned today by trucks can be attributed to overcoming aerodynamic resistance.
Combining the two wheels normally found on a rear axle into a single, thinner wheel provides a smoother ride and better fuel economy from the reduced surface area and improved tire-wall stiffness.
Wind skirts under the trailer significantly reduce wind resistance and airflow around the trailer, which is a big fuel-economy benefit.
According to a study by the Rocky Mountain Institute, by using known technologies, Wal-Mart can improve the efficiency of cars and light trucks by up to five times (three times using gasoline). Class 8 trucks (medium-haul tractor-trailers), the kind Wal-Mart relies upon, can also see doubled or even tripled efficiency.Moreover, since nearly two-thirds of all new Class 8 trucks are bought by the 100 largest companies, Wal-Mart can influence truck design by demanding better-mileage vehicles, and possibly also by pooling its demand with other big fleets.