This report is sixth in a series of reports on automobile control technology and is based on information submitted to EPA from automobile manufacturers during the time period of December 1976 through February 1977. The report contains conclusions about emission standards and the years in which they could be implemented, the relationship between fuel economy and emission control, the potential differences in emission control technology at different emission levels, the possible impact of MMT, unregulated emissions of concern, the impact of a non-methane hydrocarbon standard, and the rate of progress in the emission control area. Significant development trends are highlighted in the following areas: 3-way catalysts; improved fuel metering; electronic controls; non-catalytic emission control technology; vehicle space requirements for emission controls; turbocharging; and diesel engine developments. A review of each manufacturer's emission control development efforts is included.