The next step is coming soon. The White House is expected to announce proposed changes to CAFE rules to limit greenhouse gas emissions from automobiles – something called the "Clean Cars" rule – later today. Currently, the Department of Transportation manages fuel economy standards, the Environmental Protection Agency deals with emissions, and individual states like California can use the Clean Air Act to create even more stringent rules. Since 2004, California, 13 other states and the District of Columbia have done just that. The problem is, these conflicting standards could create a situation where car makers have to deal with rules from three separate agencies. The Clean Cars rule will be a national standard that California will support and the DOT and EPA will both adopt.
The combined EPA and National Highway Traffic Safety Administration ( NHTSA) standards that make up this proposed national standard (Clean Cars) would apply to passenger cars, light-duty trucks, and medium-duty passenger vehicles, covering model years 2012 through 2016. The new rules would require these vehicles to meet an estimated combined average emissions level of 250 grams of carbon dioxide per mile, equivalent to 35.5 miles per gallon if the automobile industry were to meet this carbon dioxide level solely through fuel economy improvements. More than likely, the 35.5-mpg equivalent will only be achieved by actually getting the fleet to 34 mpg, and the remaining 1.5 mpg equivalent will be achieved through improvements in air conditioning systems. Together, the EPA says that these proposed standards would cut carbon dioxide emissions by an estimated 217 million metric tons and reduce U.S. crude dependency by 1.5 billion barrels of oil.
Under this proposed national program, automobile manufacturers would be able to build a single light-duty national fleet that satisfies all requirements under both the National Program and the standards of California and other states, while ensuring that consumers still have a full range of vehicle choices. The final numbers are expected soon. Stay tuned.[Source: Environmental Protection Agency]