Emission levels

Hybrids are typically certified to very stringent tailpipe emission levels defined by the California Air Resources Board and the US Environmental Protection Agency.

Every 2008 Prius sold in the U.S. is mechanically equipped to meet the California SULEV [prius_sulev] emission standard. However, since gasoline available outside of California is not as clean burning, Prius is certified to the Tier 2/Bin 3 standard for Federal emissions compliance.

California has adopted a designation for vehicles with SULEV [prius_sulev] exhaust emissions, zero fuel evaporative emissions, 150,000-mile emissions durability and an extended emission systems warranty. Vehicles certified to meet these requirements are referred to as Advanced Technology Partial Zero Emission Vehicles (AT-PZEVs) [pzev]. Every 2008 Prius sold in the U.S. is mechanically equipped to meet the California AT-PZEV [pzev] emission standard. However, they are only designated as AT-PZEVs [pzev] in California and states having adopted the California regulations.