The U.S. Environmental Protection Agency (EPA) has proposed tougher tailpipe and evaporative emissions standards known as “Tier 3” to take effect in 2017, according to the Specialty Equipment Market Association (SEMA).
Reduced tailpipe emissions standards for particulate matter, non-methane organic gases and nitrogen oxides would be phased-in between 2017 and 2025, and the useful life period would be raised from 120,000 miles to 150,000 miles. The evaporative emissions standards would also be reduced by nearly 50% from current standards and the useful life period raised to 150,000 miles. The EPA would also adopt California’s Onboard Diagnostic System (OBD) requirements.
SEMA says Tier 3 would lower the sulfur content in gasoline by nearly two-thirds. California has already adopted this approach as of 2017, and the automakers are relying on the fuel to run lean-burn gasoline direct-injection engines and allow the vehicle’s catalytic converter to work more efficiently.
Under Tier 3, new vehicles would be tested and certified to gasoline with 15% ethanol (E15) rather than 10% (E10). The rule would apply to all light-duty vehicles, medium-duty passenger cars and some heavy-duty vehicles.