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Reducing Exhaust Emissions

Exhaust emissions of SU-LEVs (Japan)

Beginning with compliance with the U.S. Clean Air Act Extension of 1970, Nissan proactively sets strict goals and targets for the design and production of our vehicles, with the ultimate goal of emissions as clean as the atmosphere. We have worked to develop a wide range of technologies, including (1) improvements for cleaner burning of fuel, (2) catalytic converters to reduce emissions, and (3) ways to use gasoline evaporations from fuel tanks. The emissions levels of today's cleanest gasoline-powered vehicles (U-LEV*1 and SU-LEV*2) achieve 1/100 to 1/250 of the levels defined in the 1970 regulations.

  • *1 U-LEV: Ultra-Low Emission Vehicle. A vehicle producing 50% less nitrogen oxide (NOx) and hydrocarbon (HC) than the level prescribed in the 2005 emission standards.
  • *2 SU-LEV: Super-Ultra Low Emission Vehicle. A vehicle producing 75% less nitrogen oxide (NOx) and hydrocarbon (HC) than the level prescribed in the 2005 emission standards.

The Sentra CA

The Bluebird Sylphy

Our Sentra CA, released in the United States in January 2000, was the first gasoline-powered car in the world to receive Partial Zero Emissions Vehicle (PZEV) certification* in compliance with the emissions requirements of the California Air Resources Board.
The Bluebird Sylphy, released in Japan in August 2000, became the first vehicle to gain certification from the Ministry of Transport (now the Ministry of Land, Infrastructure, Transport and Tourism) as an Ultra-Low Emission Vehicle (U-LEV) producing 50% less nitrogen oxide (NOx) and nonmethane hydrocarbon (NMHC) than the 2005 emission standards level. In 2003, this model became Japan's first to receive SU-LEV certification as a Super Ultra-Low Emission Vehicle, with emissions at 75% less than that level.

  • * PZEV vehicles must meet requirements in the areas of Super Ultra Low Emission Vehicle tailpipe emission level and zero-evaporative emissions, be equipped with an onboard diagnostic system and have an extended warranty of 150,000 miles or 15 years.

Introduction of clean diesel vehicles

X-Trail 20GT

While diesel vehicles have an advantage in terms of energy efficiency and level of CO2 emissions, making their exhaust cleaner has been very difficult. At Nissan, we have developed technologies including a diesel particulate filter that traps and eliminates substances making up sooty exhaust, as well as NOx absorption and oxidation catalysts. These next-generation environmental technologies are used in the M9R clean diesel engine, developed through our Alliance with Renault, that comes in the X-TRAIL 20GT. This was the first vehicle to meet Japan's 2009 emissions regulations*, among the most stringent in the world. An X-TRAIL 20GT with a 6-speed automatic transmission (including manual mode) was introduced in 2010. In November 2011 we introduced an Atlas F24 1.5 ton diesel engine model, expanding Nissan's lineup of models that comply with the 2009 regulations.

  • * Japan's 2009 emission standards stipulate reductions of NOx by 47% and particulate matter by 64% from the levels required by the 2005 emission standards (applicable to vehicles weighing more than 1,265 kg). The 2009 Emission Regulations went into effect for new models in October 2009 and have been applied to existing models and imported cars since September 2010.

Emission-reduction technology meant for wide use

Ultra-Low Precious Metal Catalyst

One of the technologies that Nissan uses to pursue the two goals of effective emission reductions and lower costs is its low-heat-mass catalyst substrate, which has been put to use in vehicles certified as SU-LEVs (Super Ultra-Low Emission Vehicles, which produce 75% less emissions than prescribed by 2005 standards).
The catalytic converter, a device that reduces a vehicle's emissions, only does its work when the catalyst heats up to a certain temperature. Nissan's catalyst substrate with ultra-low heat mass makes use of extremely thin substrate walls, allowing more rapid heating of the catalyst and a drastic reduction in "light-off time" required for the unit to activate.
Catalysts use platinum-based metals. The more of these metals that go into the catalytic converter, the more effective it will be in reducing emissions, but this entails higher costs. Nissan's catalytic converter uses a honeycomb structure to increase the active surface area and maximize the unit's effectiveness with a lower amount of precious metal.
In August 2007, we realized an ultra-low precious metal catalyst that uses just half as much precious metal as a conventional catalyst. This reduction was made possible by Nissan technologies that slow the rate at which the catalytic material loses its effectiveness.

Compressed natural gas vehicles (CNGVs)

AD CNG was certified as the first U-LEV in Japan.

CNGVs run on natural gas, giving them an advantage of lower NOx and HC emissions over diesel vehicles. What is more, CNGVs discharge almost no soot (particulate matter).

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