U.S. Tier 3 vehicle emissions and fuel quality standards, final rule

Published: 2014.03.11

John German

On 3 March 2014, U.S. EPA finalized new emission standards for vehicles and fuels, commonly referred to as Tier 3 emission standards (Docket No. EPA-HQ-OAR-2011-0135). Once the vehicle and fuel provisions are fully implemented, smog-forming volatile organic compounds and nitrogen oxides will be reduced by 80% from current levels, particulate matter will be reduced by 70%, and fuel vapor emissions will be driven to near zero levels. In addition, the medium- and heavy-duty pickup and work van tailpipe standards represent about a 60% reduction in both fleet average NMOG+NOX and per-vehicle PM standards. EPA is also extending the regulatory useful life period during which the standards apply from 120,000 miles to 150,000 miles.

Sulfur in gasoline will be reduced to 10 parts per million on average from 30 ppm today, bringing gasoline fuel requirements in line with those already in place in California, Europe, Japan, and South Korea (although these countries have a 10 ppm cap rather than a 10 ppm average, as adopted by EPA). Changes to the fuel used for certification were also adopted, reflecting the widespread use of 10% ethanol blends in commercial gasoline.

The standards, to be phased in from MY 2017 and fully implemented by MY 2025, will reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles and some heavy-duty vehicles.

The requirements of the final rule remain largely the same as in the EPA’s April 2013 Notice of Proposed Regulation, which was comprehensively summarized by ICCT here.

The final rule does make four significant changes from the proposed rule, which are detailed in this policy update:

  • Vehicle emission control cost estimates were cut from $134 per vehicle to $72 per vehicle in model year 2025, and clean fuel cost estimates, fully phased in over all gasoline, were reduced from 0.89 cents per gallon to 0.65 cents per gallon gasoline.
  • Adopted more stringent standards for Supplemental FTP (SFTP) particulate emissions
  • Changed certification fuel ethanol requirements from 15% to 10%
  • Provided fuel refineries more flexibility in phasing in sulfur reduction