Heavy-duty truck and bus engine emission rates and standards: Federal and California

This document, authored by John H. Johnson, presents federal and California emission standards for heavy-duty trucks and bus engines from 1969 through 1991, covering pollutants such as hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), and particulates measured in grams per brake horsepower-hour. It traces the evolution of U.S. vehicle emission regulations, noting that standards have tightened significantly since California first imposed automobile emission limits in 1966. The table also details changes in testing procedures, including the shift to a transient test cycle for heavy-duty vehicles effective in 1985.

Notes

This document presents continued data from Table 1 by John H. Johnson, detailing emission rates and standards for heavy-duty truck and bus engines from 1969 to 1991. It covers both Federal and California standards for hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), particulates, and evaporative emissions measured in grams per brake horsepower-hour. The document also briefly describes U.S. emission testing procedures, including the transient test cycle effective 1985.

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