To save energy, they need to be as light as possible. Generally to increase productivity they should operate quickly, hence friction should be kept as low as possible by choice of appropriate bearings, to prevent wasted energy appearing as unwanted heat. Most major car companies are taking steps to lighten their vehicles while improving their quality, to improve the efficiency of existing types of engine while reducing their unwanted exhaust emissions and investigating new power systems. Modern lubricants for automobile engines are formulated to give low exhaust emissions while causing a minimum energy loss. Blaming all atmospheric pollution on cars is however a simplification, as waste energy caused by heat losses from buildings is thought to cause even more pollution.
Aircraft also generate more atmospheric pollution per person km than road vehicles.
Disposal of Products. As many industrialised countries are running out of landfill areas, where domestic and non-hazardous waste can be dumped, there is increasing pressure to reduce the volume of a such waste. This is being tackled in several ways. Simple economics is forcing up the cost of landfill, particularly at those sites near to centres of population. Governments in some countries are adding extra pressure by imposing landfill taxes.