The environmental watchdog in the Chinese capital imposed penalties against about 1,000 vehicles in March for excessive emissions.

The Obama administration on Monday announced new fuel and automobile rules to cut soot, smog and toxic emissions, which it says will reduce asthma and heart attacks in the United States.

President Barack Obama is moving ahead to increase fuel efficiency standards.

This paper focuses on ways to reduce the emissions of the in-use vehicle fleet, with particular emphasis on heavy-duty diesel trucks, due to their disproportionate contribution to both urban air quality and greenhouse gas emissions.