US EPA adopts Tier 3 emission standards

3 March 2014

The US Environmental Protection Agency (EPA) finalized Tier 3 emission regulations for light-duty vehicles. Starting from 2017, the Tier 3 program sets new vehicle emission standards and lowers the sulfur content of gasoline. The Tier 3 rule has been adopted largely as proposed—there appear to be no major changes between the Tier 3 proposal and the adopted language.

Please log in to view the full version of this article (subscription required).

Compared to current standards, the NMOG+NOx tailpipe standards for light-duty vehicles represent approximately an 80% reduction from today’s fleet average and a 70% reduction in per-vehicle PM standards. The emission durability (useful life period) has been extended from 120,000 miles to 150,000 miles. The Tier 3 standards are coordinated with California LEV III standards, which will allow manufacturers to design and certify all US market vehicles to one set of standards.

A number of auto manufacturers—including GM, Toyota and Honda—expressed their support for the rule and for the harmonization of California and federal emission requirements. Most automakers also support the reduction of sulfur levels in gasoline, seen as an enabler of catalyst technologies (such as NOx adsorbers) that would be required for lean burn gasoline engines—one of the technologies envisioned for meeting future fuel economy and GHG standards. The Tier 3 emission and gasoline sulfur standards were also praised by the emission control catalyst industry, including MECA, Umicore and Emitec. On the other hand, the Tier 3 sulfur program has been criticized by the fuel industry who has argued that the sulfur standards will require costly refinery upgrades while providing negligible emission benefits.

The Tier 3 program is projected to cost less than a penny per gallon of gasoline, and about $72 per vehicle. The annual cost of the overall program in 2030 is projected to be approximately $1.5 billion.

Source: US EPA