The EPA was requested to test two Volkswagen Rabbits with turbocharged Diesel engines by the U.S. Department of Transportation. These were research vehicles which coupled turbochargers to small displacement Diesel engines with the objective of maintaining the fuel efficiency of the Diesel with a power output similiar to that of equal displacement gasoline engines. The DOT requested testing by the EPA as the EPA has the capability to assess the vehicle performance and emission levels. There has been limited experience in testing turbocharged Diesel engines. A small displacement Diesel with a matched turbocharger were to be evaluated by the EPA in terms of performance, fuel economy, particulate emissions, and gaseous emissions. These vehicles offered the opportunity of evaluating an automotive engine which may indicate the direction the auto industry will take in the future in an effort to minimize harmful emissions, maximize fuel economy and maintain current vehicle performance. This test program was run during the period of February 1977 to May 1978.