The Environmental Protection Agency has issued a proposed rule that would require on-board diagnostic systems (OBD) and "check engine" lights on highway trucks weighing more than 14,000 lb, starting in 2010. Cars and light trucks already have such devices, which measure tailpipe emissions, alert drivers to malfunctions and help technicians fix problems. The regulation, proposed Dec. 13, is "an important step forward" in making sure engines are "as clean in the real world as would be predicted in a laboratory test," says Natural Resources Defense Council Senior Attorney Rich Kassel.
EPA also wants comments on a similar proposal it is weighing to require OBDs for off-road construction equipment. EPA says that would be a "natural progression" from the on-road vehicle rule.