What Is a Super Ultra Low Emissions Vehicle (SULEV)?

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SULEV is an acronym for Super Ultra Low Emissions Vehicle. SULEVs are 90 percent cleaner than the current average year's models, emitting substantially lower levels of hydrocarbons, carbon monoxide, nitrous oxides and particulate matter than conventional vehicles. The SULEV standard steps up the ULEV, Ultra Low Emission Vehicle standard. 

Some PZEVs fall into this category by default. For instance, if you buy a Toyota Prius in California and fuel it up, it's considered a Partially Zero Emissions Vehicle (PZEV), however, if you drive east and fuel it up over the next 2,500 miles it's considered an SULEV since California's low sulfur gas formulations are not available everywhere.

Origins of the Term

The term originated in the United States Environmental Protection Agency, which uses SULEV to describe a class to vehicles meeting certain emissions standards. These standards are far stricter than those governing the classifications Low Emissions Vehicle (LEV) and Ultra-Low Emissions Vehicle (ULEV), while less strict than California's PZEV and Zero Emissions Vehicle (ZEV) standards.

Part of the Clean Air Act of 1990, legislation involving this nomenclature was an initiative to lessen emissions as a result of high commuter traffic and American reliance on automobiles. Nissan, however, was the first to release an engine that qualified for the SULEV rating with its 2001 release of the Nissan Sentra. 

Especially in the early 2010s, the increased interest in greener energy sparked a movement toward low-emission manufacturing with states like California pioneered the effort causing auto manufacturers to decrease their environmental impact.

Modern Usage

While the market for SULEVs is constantly expanding as the demand for better fuel efficiency and less impact on the environment continues to permeate most industries. The Honda Civic Hybrid, Ford Focus (SULEV model), Kia Forte and Hyundai Elantra all qualify as SULEV — with several also qualifying as PZEVs.

Today, more than 30 makes and models qualify as SULEVs. These vehicles radically reduce the emissions created by traffic and congestion, often times producing zero emissions while they carry passengers about their lives. 

Thanks to the 90% fewer emissions of these vehicles, the human impact on global warming is decreasing each year. Perhaps, in time, we may even move away from these highly efficient vehicles to ones that don't rely on gasoline at all.