This guidance was developed to clarify how the on-road testing requirement can be met in states with mandatory enhanced vehicle emission inspection and maintenance (I/M) programs. On-road testing is a necessary element of an I/M program that is required by the Clean Air Act (CAA) to be operated at the enhanced performance level. On-road testing involves the collection of emissions data from a samp...

EPA has adopted emission standards for almost every kind of engine, including everything from lawn mowers to cruise ships. To show compliance with these emission standards, engine manufacturers must follow test procedures specified in the Code of Federal Regulations. This page provides links to the appropriate regulatory citations and includes published information related to the test procedures. ...

On December 20, 2022, EPA adopted a final rule, “Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards,” that sets stronger emissions standards to further reduce air pollution, including pollutants that create ozone and particulate matter, from heavy-duty vehicles and engines starting in model year 2027. The final program includes new, more stringent emissions s...

The Clean Air Act (CAA) is the comprehensive federal law that regulates air emissions from stationary and mobile sources. Among other things, this law authorizes EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and public welfare and to regulate emissions of hazardous air pollutants.NAAQS and SIPsOne of the goals of the Act was to set and achieve NAAQS in ev...

The purpose of this appendix is to provide the road load power calculation method that may be used, at the choice of manufacturer, when the vehicle road load has been determined according to WLTP procedures as defined in UNGTR No. 15....

The Emission Standard for Mobile-source Pollutants section on the Ministry of Ecology and Environment (MEE) website lists China’s national standards regulating pollutant emissions from various mobile sources, including light-duty and heavy-duty vehicles, motorcycles, mopeds, marine engines, and non-road mobile machinery....

This page provides links to regulations for controlling greenhouse gas emissions, smog, soot and other air pollution from onroad vehicles.Passenger Vehicles (Light-Duty):Regulations for GHG emissions from passenger cars & trucksRegulations for smog, soot, and other air pollution from passenger cars & trucksCommercial Trucks & Buses (Heavy-Duty):Final Rule Improvements Heavy Duty Engine...

The Euro emission standards were introduced to reduce air pollution from road transport and to prevent fragmentation of the EU Single Market. Since 1992, successive standards have progressively tightened pollutant limits for cars, vans, lorries, and buses while modernizing testing procedures. The current Euro 6 (light-duty) and Euro VI (heavy-duty) standards set stricter limits for key pollutants ...

Diesel road transport is a major source of black carbon (BC) and fine particulate matter (PM2.5), with heavy-duty diesel vehicles contributing the largest share. While some countries have adopted low-sulfur fuels and soot-free vehicle standards requiring diesel particulate filters (DPFs), significant gaps remain in fuel quality and regulatory coverage worldwide. The CCAC strategy calls for univers...