Around the world, automakers and their suppliers are working to make motor vehicles environmentally friendlier. The strictest standards have been set for markets in Europe and the United States. The general goal of not polluting is the same in both regions, but the paths toward reaching this goal are different. In Europe, the focus is on the self-imposed industry requirement of reducing fuel consumption measured by carbon dioxide emissions (CO2). The US-government is focusing requirements on reducing the emission of toxic substances. As a rule, these goals are the same for spark ignition and diesel engines.