The U.S. Environmental Protection Agency (EPA) has issued a final rule doubling the per-engine penalty for heavy-duty engines that do not meet federal standards of 0.2 grams of nitrogen oxide (NOx) per brake horsepower-hour. 77 Fed. Reg. 54,384 (9/5/2012). EPA’s nitrogen oxide limits for heavy-duty diesel engines are technology-forcing, and manufacturers that do not meet the limits can apply for a nonconformance penalty to allow them to sell engines in the United States. Penalties depend in part on whether the engines perform within the top 50 or 90 percent of heavy-duty engines. EPA has increased the maximum penalties from $1,900 per engine to nearly $3,800 for engines emitting near the absolute limit of 0.5 grams of NOx per brake horsepower-hour.

The rule affects heavy-duty diesel engine NOx standards only. EPA did not establish penalties for heavy-duty diesel engine carbon monoxide, particulate or non-methane hydrocarbon standards; for “light heavy-duty diesel” NOx emissions; or for any emissions standards applicable to heavy-duty gasoline engines. In addition to the changes in the nonconformance penalties, the rule provides that no carbon dioxide emission credits can be used for engines paying a nonconformance penalty for NOx.