Heavy Duty Diesel Emission Regulations - Past, Present, and Future

Exhaust emissions from heavy-duty truck and bus diesel engines have been legislated from 1970 to 2010. Smoke emissions continue to be controlled but exhaust odor regulations were never promulgated. Gaseous emissions (oxides of nitrogen, carbon monoxide and hydrocarbons) were regulated in 1973 and particulate matter first regulated in 1988. Throughout this period there has been cooperation, lawsuits, statement of principles, Consent Decrees and now The Clean Diesel Independent Review Panel. If the 2010 rulemaking remains in place, diesel emissions of NOx and PM will have been reduced 99% from uncontrolled levels.