The U.S. Environmental Protection Agency (EPA) has issued tougher tailpipe and evaporative emissions standards known as “Tier 3.” Reduced tailpipe emissions standards for particulate matter, non-methane organic gases and nitrogen oxides will be phased-in between 2017 and 2025, and the useful life period will be raised from 120,000 miles to 150,000 miles. The evaporative emissions standards will also be reduced by nearly 50% from current standards and the useful life period raised to 150,000 miles. The EPA will also adopt California’s Onboard Diagnostic System (OBD) requirements.Tier 3 will lower the sulfur content in gasoline by more than 60%. 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 will be tested and certified to gasoline with 10% ethanol (E10) rather than 15% (E15) as originally proposed. The rule will apply to new light-duty vehicles, medium-duty passenger cars and some heavy-duty vehicles.
By SEMA Washington, D.C., Staff