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In the United States, emissions standards are managed nationally by the Environmental Protection Agency (EPA). State and local governments may apply for waivers to enact stricter regulations.
Due to its preexisting standards and particularly severe motor vehicle air pollution problems in the Los Angeles metropolitan area, the U.S. state of California has special dispensation from the federal government to promulgate its own automobile emissions standards. Other states may choose to follow either the national standard or the stricter California standards. The states that have adopted the California standards are: Colorado, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New Mexico (2011 model year and later), New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington, as well as the District of Columbia. [1] [2] [3] Such states are frequently referred to as "CARB states" in automotive discussions because the regulations are defined by the California Air Resources Board.
The EPA has adopted the Californian emissions standards as a national standard by the 2016 model year [4] and is collaborating with Californian regulators on stricter national emissions standards for model years 2017–2025. [5]
Light-duty vehicles are certified for compliance with emission standards by measuring their tailpipe emissions during rigorously-defined driving cycles that simulate a typical driving pattern. The FTP-75 city driving test (averaging about 21 MPH) and the HWFET highway driving test (averaging about 48 MPH) are used for measuring both emissions and fuel economy.
Two sets, or tiers, of emission standards for light-duty vehicles in the United States were defined as a result of the Clean Air Act Amendments of 1990. The Tier I standard was adopted in 1991 and was phased in from 1994 to 1997. Tier II standards were phased in from 2004 to 2009.
Within the Tier II ranking, there is a subranking ranging from BIN 1–10, with 1 being the cleanest (Zero Emission vehicle) and 10 being the dirtiest. The former Tier 1 standards that were effective from 1994 until 2003 were different between automobiles and light trucks (SUVs, pickup trucks, and minivans), but Tier II standards are the same for both types.
These standards specifically restrict emissions of carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter (PM), formaldehyde (HCHO), and non-methane organic gases (NMOG) or non-methane hydrocarbons (NMHC). The limits are defined in grams per mile (g/mi).
Were phased in from 1994 to 1997, and were phased out in favor of the national Tier 2 standard, from 2004 to 2009.
Tier I standards cover vehicles with a gross vehicular weight rating (GVWR) below 8,500 pounds (3,856 kg) and are divided into five categories: one for passenger cars, and four for light-duty trucks (which include SUVs and minivans) divided up based on the vehicle weight and cargo capacity.
California's Low-emission vehicle (LEV) program defines six automotive emission standards which are stricter than the United States' national Tier regulations. Each standard has several targets depending on vehicle weight and cargo capacity; the regulations cover vehicles with test weights up to 14,000 pounds (6,350 kg). Listed in order of increasing stringency, the standards are: [6]
The last category is largely restricted to electric vehicles and hydrogen cars, although such vehicles are usually not entirely non-polluting. In those cases, the other emissions are transferred to another site, such as a power plant or hydrogen reforming center, unless such sites run on renewable energy.
A set of transitional and initially voluntary "national low emission vehicle" (NLEV) standards were in effect starting in 1999 for northeastern states and 2001 in the rest of the country until Tier II, adopted in 1999, began to be phased in from 2004 onwards. The National Low Emission Vehicle program covered vehicles below 6,000 pounds GVWR and adapted the national standards to accommodate California's stricter regulations.
Instead of basing emissions on vehicle weight, Tier II standards are divided into several numbered "bins". Eleven bins were initially defined, with bin 1 being the cleanest (zero-emission vehicle) and 11 the dirtiest. However, bins 9, 10, and 11 are temporary. Only the first ten bins were used for light-duty vehicles below 8,500 pounds GVWR, but medium-duty passenger vehicles up to 10,000 pounds (4,536 kg) GVWR and to all 11 bins. Manufacturers can make vehicles which fit into any of the available bins, but still must meet average targets for their entire fleets.
The two least-restrictive bins for passenger cars, 9 and 10, were phased out at the end of 2006. However, bins 9 and 10 were available for classifying a restricted number of light-duty trucks until the end of 2008, when they were removed along with bin 11 for medium-duty vehicles. As of 2009, light-duty trucks must meet the same emissions standards as passenger cars.
Tier II regulations also defined restrictions for the amount of sulfur allowed in gasoline and diesel fuel, since sulfur can interfere with the operation of advanced exhaust treatment systems such as selective catalytic converters and particulate filters. Sulfur content in gasoline was limited to an average of 120 parts-per-million (maximum 300 ppm) in 2004, and this was reduced to an average 30 ppm (maximum 80 ppm) for 2006. Ultra-low sulfur diesel began to be restricted to a maximum 15 ppm in 2006 and refiners are to be 100% compliant with that level by 2010.
In 2009, President Obama announced a new national fuel economy and emissions policy that incorporated California's contested plan to curb greenhouse gas emissions on its own, apart from federal government regulations.
The combined fleet fuel economy for an auto manufacturer of cars and trucks with a GVWR of 10,000 lbs or less will have to average 35.5 miles per gallon (mpg). The average for its cars will have to be 42 mpg, and for its trucks will be 26 mpg by 2016, all based upon CAFE Standards. [7] If the average fuel economy of a manufacturer's annual fleet of vehicle production falls below the defined standard, the manufacturer must pay a penalty, currently $5.50 USD per 0.1 mpg under the standard, multiplied by the manufacturer's total production for the U.S. domestic market. [8] This is in addition to any gas guzzler tax, if applicable. [9]
A second round of California standards, known as Low Emission Vehicle II, is timed to coordinate with the Tier 2 rollout.
The PZEV and AT-PZEV ratings are for vehicles which achieve a SULEV II rating and also have systems to eliminate evaporative emissions from the fuel system and which have 150,000-mile/15-year warranties on emission-control components. Several ordinary gasoline vehicles from the 2001 and later model years qualify as PZEVs.
If a PZEV has technology that can also be used in ZEVs like an electric motor or high-pressure gaseous fuel tanks for compressed natural gas (CNG) or liquified petroleum gas (LPG), it qualifies as an AT-PZEV.
Heavy-duty vehicles must comply with more stringent exhaust emission standards and requires ultra-low sulfur diesel (ULSD) fuel (15 ppm maximum) beginning in 2007. [10] Since 2007 only diesel models are allowed in the heavy duty class; the EPA banned gasoline models in 2007.[ citation needed ]
Federal emissions regulations cover the primary component of vehicle exhaust, carbon dioxide (CO2). Since CO2 emissions are proportional to the amount of fuel used, the national Corporate Average Fuel Economy regulations are the primary way in which automotive CO2 emissions are regulated in the U.S. The EPA faced a lawsuit seeking to compel it to regulate greenhouse gases as a pollutant, Massachusetts v. Environmental Protection Agency.
As of 2007, the California Air Resources Board passed strict greenhouse gas emission standards [11] which are being challenged in the courts. [12]
On September 12, 2007, a judge in Vermont ruled in favor of allowing states to conditionally regulate greenhouse gas (GHG) emissions from new cars and trucks, defeating an attempt by automakers to block state emissions standards. A group of automakers including General Motors, DaimlerChrysler, and the Alliance of Automobile Manufacturers had sued the state of Vermont in order to block rules calling for a 30 percent reduction in GHG emissions by 2016. Members of the auto industry argued that complying with these regulations would require major technological advances and raise the prices of vehicles as much as $6,000 per automobile. U.S. District Judge William K. Sessions III dismissed these claims in his ruling. "The court remains unconvinced automakers cannot meet the challenge of Vermont and California's (greenhouse gas) regulations," he wrote.
Meanwhile, environmentalists continue to press the Administration to grant California a waiver from the EPA in order for its emissions standards to take effect. Doing so would allow Vermont and other states to adopt these same standards under the Clean Air Act. Without such a waiver, Judge Sessions wrote, the Vermont rules will be invalid. [13] [14] [15]
EPA's air pollution score [16] represents the amount of health-damaging and smog-forming airborne pollutants the vehicle emits. Scoring ranges from 0 (worst) to 10 (best). The pollutants considered are nitrogen oxides (NOx), particulate matter (PM), carbon monoxide (CO), formaldehyde (HCHO), and various hydrocarbon measures – non-methane organic gases (NMOG), and non-methane hydrocarbons (NMHC), and total hydrocarbons (THC). This score does not include emissions of greenhouse gases (but see Greenhouse gas score, below).
EPA's greenhouse gas score [16] reflects the amount of greenhouse gases a vehicle will produce over its lifetime, based on typical consumer usage. The scoring is from 0 to 10, where 10 represents the lowest amount of greenhouse gases.
The Greenhouse gas score is determined from the vehicle's estimated fuel economy and its fuel type. The lower the fuel economy, the more greenhouse gas is emitted as a by-product of combustion. The amount of carbon dioxide emitted per liter or gallon burned varies by fuel type, since each type of fuel contains a different amount of carbon per gallon or liter.
The ratings reflect carbon dioxide (CO2), nitrous oxide (N20) and methane (CH4) emissions, weighted to reflect each gas' relative contribution to the greenhouse effect.
Non-road engines, including equipment and vehicles that are not operated on the public roadways, are used in an extremely wide range of applications, each involving great differences in operating characteristics and engine technology. Emissions from all non-road engines are regulated by categories. [17]
In the United States, the emission standards for non-road diesel engines are published in the US Code of Federal Regulations, Title 40, Part 89 (40 CFR Part 89). Tier 1-3 Standards were adopted in 1994 and was phased in between 1996 and 2000 for engines over 37 kW (50 hp). In 1998 the regulation included engines under 37 kW and introduced more stringent Tier 2 and Tier 3 standards which was scheduled to be phased in between 2000 and 2008. In 2004, US EPA introduced the more stringent Tier 4 standards which was scheduled to be phased in between 2008 and 2015. The testing cycles used for certification follow the ISO 8178 standards.
Pollution from small engines, such as those used in gas-powered groundskeeping equipment reduces air quality. Emissions from small offroad engines are regulated by the EPA. [18] Specific pollutants subject to limits include hydrocarbons, carbon monoxide, and nitrogen oxides. [19]
Performance-based regulation of greenhouse gases from electricity generation has been initiated on the state level. California was the first to implement this standard in January 2007 by adopting Senate Bill 1368, which set a limit of 1,100 lbs. CO2 per megawatt-hour on "new long-term commitments" for baseload power generation. [20] This legislation was intended to apply to new plant investments (new construction), new or renewal contracts with a term of five years or more, or major investments by the electrical utility in its existing baseload power plants. [20] The number of 1,100 lbs. CO2/MWhr corresponds to the emissions per electrical output of a combined cycle gas turbine plant. By comparison, coal-fired steam turbine plants produce 2,200 lbs. CO2/MWhr or more. [21] Other western states followed suit soon after California, with Oregon, Washington, and Montana passing similar bills into law later that year. [22]
In 2009, the California Air Resources Board (CARB) has established rules for allowable emissions of formaldehyde from wood products made of pieces, chips, particles, or fibers of wood bonded together with a resin. [23] In 2016, the United States the Environmental Protection Agency also issued regulations to limit formaldehyde emissions. [24]
Individual states with areas that do not attain the targets set by the EPA in the National Ambient Air Quality Standards must promulgate specific regulations which reduce the corresponding emissions from local sources.[ citation needed ]
 | This section needs expansion. You can help by adding to it.(August 2011) |
| Name | Light duty gasoline | Emissions testing | Light-duty diesel | Emissions testing | Heavy-duty diesel | Emissions testing | Special notes |
|---|---|---|---|---|---|---|---|
| Alabama [25] | No emissions testing required | No emissions testing required | Alabama maintains "volunteer emission testing" | ||||
| Alaska [26] | ≥6 model years old (Anchorage) | Biennially | Exempt | Exempt | |||
| Arizona [27] [28] | Model Years ≥1967 but more than 5 model years old (Pima County/ Maricopa County) | Biennially | 1967–2007 (Pima County/ Maricopa County) | Pima County: 30 percent opacity
| Maricopa County | J1667 test protocol
| Only state which still conduct emission testing dating back to the 1967 model year unlike other states using EPA classification (a few still conduct test for 1968–present (1968+ testing is for jurisdictions using defined EPA standards for vehicle classification since the '68 model year and beyond automobiles must have an exhaust emission system - PCV system, air injection pump, controlled spark module) e.g. the absence of a rolling chassis exemption - in some states when an automobile reaches an age limit (as in 25 model years old) the vehicle is exempted or pertaining to motor vehicle laws e.g. classic automobile registration and displaying vintage license plates |
| Arkansas | |||||||
| California | vehicles 1976 and newer model-year gas-powered, hybrid, and flex-fuel vehicles; exemptions: new car = ≤6 model-years old are exempt; change of ownership = ≤4 model-years old are exempt | required biennially for registration renewal; 2000 model-year and newer receive only visual and OBDII inspections | vehicles 1998 and newer model-year diesel-powered vehicles with a GVWR ≤14,000 pounds; exemptions: none applicable to diesel-powered vehicles | required biennially for registration renewal; 1998 model-year and newer receive only visual and OBDII inspections | California-based fleets of 2 or more heavy-duty vehicles with a GVWR >14,000 pounds | Periodic Smoke Inspection Program (PSIP) an annual smoke and tamper self-inspection; exemptions: new vehicle = ≤4 model-years old are exempt | Prior to 2004 emission testing included 1966 and newer model year automobiles - 1984 calendar year phased in the use of an acceleration simulated mode test criteria - a 1998 state law made pre-1973 automobiles exempt from emission testing where it temporarily included a 30-year rolling chassis exemption which was repealed in 2006 where 1976 and newer are subjected to state mandated emission testing - California visual inspection strictest in the USA (also similar to Japanese 'Shaken' vehicle laws which is their equivalent of vehicle inspection) which serves as a model for other states implementing I/M (inspection/maintenance) programs |
| Colorado [29] | Vehicles older than 4 years required, this will change to 7 years in 2015. Specially registered cars made before 1975 and special vehicles may be exempted. | Biennially when required | Exempt for first seven model years of gasoline vehicles. | When outside exemption, vehicles up to 32 years old - biennially, else annually. OBD testing done when newer than 10 years | Exempt for first four model years of diesel vehicles. | When outside exemption, diesel trucks less than 10 years - Biennially else annually. | Only on high population corridor encompassing Castle Rock to Wellington, including Boulder and Greeley. Required for vehicles used in this area. Dynamometer testing used. |
| Connecticut [30] | more than 4 model years old but less than 25 model years old | Biennially (OBDII) | more than 4 model years old but less than 25 model years old | Biennially | Exempt | ||
| Delaware [31] | Over 5 model years old | Biennially (OBDII) | |||||
| Florida | |||||||
| Georgia | Annually (Atlanta metro area only) | ||||||
| Hawaii | |||||||
| Idaho | |||||||
| Illinois | Biennially, after the vehicle is four years old | Required only in the Chicago metropolitan area and eastern suburbs of St. Louis, Missouri | |||||
| Indiana | |||||||
| Iowa | |||||||
| Kansas | |||||||
| Kentucky | |||||||
| Louisiana | |||||||
| Maine | |||||||
| Maryland | Biennially | Hybrid vehicles that achieve an EPA gas mileage rating of at least 50 miles per gallon are exempt from testing for 3 years after their model year, after which they are then tested at the standard two year intervals. | |||||
| Massachusetts [32] [33] | Every year | OBDII | Every year | OBDII | 8,501 to 14,000 lbs (Medium duty)
| Medium Duty: OBDII
| |
| Michigan | |||||||
| Minnesota | |||||||
| Mississippi | |||||||
| Missouri | |||||||
| Montana | |||||||
| Nebraska | |||||||
| Nevada | Model years 1968 and newer | ||||||
| New Hampshire | |||||||
| New Jersey | Model years ≥ 1995 Must be inspected biennially. Model years ≤ 1995 do not require inspection. | ||||||
| New Mexico [34] [35] | Model Years ≥1978 but more than 4 model years old (Bernalillo County) | Biennially and at change of ownership | Model Years ≥1978 but more than 4 model years old (Bernalillo County) | Biennially and at change of ownership | Exempt | ||
| New York | |||||||
| North Carolina | |||||||
| North Dakota | |||||||
| Ohio | More than 4 model years old but less than 25 model years old in the Greater Cleveland area [36] | Biennially (OBDII) | More than 4 model years old but less than 25 model years old in the Greater Cleveland area | Biennially (OBDII) | Testing was also required in the Cincinnati and Dayton Metropolitan areas from 1995-2005 | ||
| Oklahoma | |||||||
| Oregon [37] [38] | Vehicles must be tested every other year for registration renewal in the Portland and Medford areas. Model Years ≥1975 must be tested in Portland area, and those 20 model year and newer in Medford area. Also all vehicles new to Oregon. | Biennially | Same intervals and exemptions as gasoline cars, 8,500 lbs or less | Biennially | ≥8,501 lbs | Exempt | |
| Pennsylvania | |||||||
| Rhode Island [39] [40] [41] | more than 2 models years old (inclusive) or 24,000 miles (inclusive) | Biennially (OBDII) | Exempt | Exempt | Effective July 2012, any state contracted job requiring heavy duty vehicles must be operated with pollution control devices | ||
| South Carolina | |||||||
| South Dakota | |||||||
| Tennessee [42] | Any gasoline vehicle with a model year of 1975 and newer and a GVWR of 10,500 lbs or less. Motorcycles are exempt. | Annual testing. OBDII + catalytic converter tamper check + fuel cap leak test for 1996 or later vehicles. Tailpipe/tampering testing for 1995 and older vehicles. | Any diesel vehicle with a model year of 1975 and newer and a GVWR of 10,500 lbs or less. | Annual testing. OBDII + catalytic converter tamper check + fuel cap leak test for 2002 or later vehicles. Curb Idle-opacity/tampering testing for 2001 and older vehicles. | Exempt | Only applies to Hamilton (Chattanooga), Davidson, Rutherford, Sumner, Williamson, and Wilson (all part of Greater Nashville area) Counties. Required for registration renewal. Davidson county runs their own emissions programs/facilities with the assistance of the state. Shelby County (Memphis) formerly required testing, but ended their program in July 2013 due to funding issues and no state support. [43] | |
| Texas | more than 2 model years old to 24 model years old; motorcycles, diesel-powered, and automobiles 25 model years or older exempt from emission testing - includes motor vehicles registered as an Antique or Classic under Texas law (either displaying state-mandated vanity license plate or vintage-era license plates (this also includes past general issue plates from 1975–present with validation stickers used prior to the 1995–present windshield sticker; license plate law in Texas (effective since May 1988) requires new general issue plates after it reaches 8 years of age - license plate law was amended 11.1.16 where TxDMV no longer mandates plate replacement every 8 years with the exception that the license plate is considered legible e.g. loss of reflectivity with the paint base and/or if a license plate is unreadable if a police officer does a probable cause traffic stop) | annually (both OBDII for 1996–present and ASM to 1995 for motor vehicles registered in the DFW Metroplex and Houston Metro area except for 4-wheel drive/all wheel drive powertrains (4WD/AWD including vehicles over 8500 GVW are subjected to the two-speed idle (TSI) testing; TSI testing to 1995 only in El Paso, Travis, and Williamson Counties) | Emission testing mandated for motor vehicles registered in the Houston Metropolitan area (Brazoria, Fort Bend, Galveston, Harris, Montgomery), DFW Metroplex (Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant), Austin Metropolitan area (Travis, Williamson) and El Paso counties; since March 1, 2015 inspection stickers no longer issued where an automobile must pass the safety or emission test prior to renewing automobile registration | ||||
| Utah | |||||||
| Virginia [44] | more than 2 model years old to 24 model years old | Biennially. First-time registrations exempt if vehicle has received an emissions certificate from certain states within previous 12 months. | newer than 1996 model year | Biennially | GVWR > 8500 lbs. exempt | Emission testing mandated for motor vehicles registered in the counties of Arlington, Fairfax, Loudoun, Prince William, or Stafford, and the cities of Alexandria, Fairfax, Falls Church, Manassas or Manassas Park. Certain hybrids exempt. | |
| Washington [45] [46] [47] [48] | Vehicles tested every other year depending on model year. Vehicles model year 2009 and newer and those >25 model years old are exempt from testing. (Clark, King, Pierce, Snohomish and Spokane counties). | Biennially. Exempt after 25 years. | All diesel passenger vehicles are exempt if weight is under 6,000 lbs. | Vehicles > 6,000 lbs and older than 2007 require testing. 2007 and newer exempt regardless of weight. | Biennially. Odd model years on odd test years, even model years on even test years. Exempt after 25 years. | Emission testing required for most of Clark, King, Pierce, Snohomish and Spokane counties. Vehicles exempt from testing are Motorcycles, 2009 and newer model vehicles, Hybrids that attain greater than 50 miles per gallon city, all diesel passenger vehicles under 6,001 lbs GVWR, all diesel vehicles model year 2007 and newer regardless of weight. | |
| West Virginia | No emissions testing required | No emissions testing required | |||||
| Wisconsin [49] | Testing required for vehicles model years 1996 and later in Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan, Washington and Waukesha counties (model years 1996 to 2006 up to 8,500 pounds; model years 2007 or newer up to 14,000 pounds) () | Every other year before registration renewal; after transfer of ownership; after registration in Wisconsin | Testing required for vehicles model years 1996 and later in Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan, Washington and Waukesha counties: Model years 2007 and newer which have a gross vehicle rating up to 14,000 pounds | Every other year before registration renewal; after transfer of ownership; after registration in Wisconsin | Greater than 14,000 lbs. | Exempt | |
| Wyoming |
The California Air Resources Board is the "clean air agency" in the government of California. Established in 1967 when then-governor Ronald Reagan signed the Mulford-Carrell Act, combining the Bureau of Air Sanitation and the Motor Vehicle Pollution Control Board, CARB is a department within the cabinet-level California Environmental Protection Agency.
The Corporate Average Fuel Economy (CAFE) standards are regulations in the United States, first enacted by the United States Congress in 1975, after the 1973–74 Arab Oil Embargo, to improve the average fuel economy of cars and light trucks produced for sale in the United States. They are set by the Secretary of Transportation, currently Elaine Chao, via the National Highway Traffic Safety Administration.
Vehicle emissions control is the study of reducing the emissions produced by motor vehicles, especially internal combustion engines.
Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life.
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline, petrol, biodiesel blends, diesel fuel, fuel oil, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.
AirCare was an initiative started in 1992 to improve air quality in British Columbia, Canada through the systematic testing of road vehicles in order to reduce their emissions. Light-duty vehicles were suggested to be the biggest contributors to air pollutants that form smog and a small percentage of vehicles were contributing a large percentage of the pollutants. AirCare ran for 22 years and was cancelled on December 31, 2014. AirCare was cancelled due to the fact that new vehicles were continuously becoming more eco-friendly, and the percentage of old cars on the road was decreasing.
Vehicle size classes are series of ratings assigned to different segments of automotive vehicles for the purposes of vehicle emissions control and fuel economy calculation. Various methods are used to classify vehicles; in North America, passenger vehicles are classified by total interior capacity while trucks are classified by gross vehicle weight rating (GVWR). Vehicle segments in the European Union use linear measurements to describe size. Asian vehicle classifications are a combination of dimensions and engine displacement.
The Monroney sticker or window sticker is a label required in the United States to be displayed in all new automobiles and includes the listing of certain official information about the car. The window sticker was named after Almer Stillwell "Mike" Monroney, United States Senator from Oklahoma. Monroney sponsored the Automobile Information Disclosure Act of 1958, which mandated the disclosure of equipment and pricing information on new automobiles.
The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance travelled per unit volume of fuel consumed. Since fuel consumption of vehicles is a significant factor in air pollution, and since importation of motor fuel can be a large part of a nation's foreign trade, many countries impose requirements for fuel economy. Different methods are used to approximate the actual performance of the vehicle. The energy in fuel is required to overcome various losses encountered while propelling the vehicle, and in providing power to vehicle systems such as ignition or air conditioning. Various strategies can be employed to reduce losses at each of the conversions between the chemical energy in the fuel and the kinetic energy of the vehicle. Driver behavior can affect fuel economy; maneuvers such as sudden acceleration and heavy braking waste energy.
An ultra-low-emission vehicle (ULEV) is a motor vehicle that emits extremely low levels of motor vehicle emissions compared to other vehicles. In some jurisdictions it is defined in law; low and ultra low emission vehicles may be given tax or other advantages, while high emission vehicles may suffer restrictions or additional taxation.
The United States produced 5.46 billion metric tons of carbon-dioxide equivalent greenhouse gas (GHG) emissions in 2018, the second lowest since the early 1990s, but still the second largest in the world after greenhouse gas emissions by China and among the worst countries by greenhouse gas emissions per person. From year to year, emissions rise and fall due to changes in the economy, the price of fuel and other factors. The US Environmental Protection Agency attributed recent decreases to a reduction in emissions from fossil fuel combustion, which was a result of multiple factors including switching from coal to natural gas consumption in the electric power sector; warmer winter conditions that reduced demand for heating fuel in the residential and commercial sectors; and a slight decrease in electricity demand.
The Not-To-Exceed (NTE) standard promulgated by the United States Environmental Protection Agency (EPA) ensures that heavy-duty truck engine emissions are controlled over the full range of speed and load combinations commonly experienced in use. NTE establishes an area under the torque curve of an engine where emissions must not exceed a specified value for any of the regulated pollutants. The NTE test procedure does not involve a specific driving cycle of any specific length. Rather it involves driving of any type that could occur within the bounds of the NTE control area, including operation under steady-state or transient conditions and under varying ambient conditions. Emissions are averaged over a minimum time of thirty seconds and then compared to the applicable NTE emission limits.
Idle reduction describes technologies and practices that minimize the amount of time drivers idle their engines. Avoiding idling time has a multitude of benefits including: savings in fuel and maintenance costs, extending vehicle life, and reducing damaging emissions. An idling engine consumes only enough power to keep itself and its accessories running, therefore, producing no usable power to the drive train.
The EPA Federal Test Procedure, commonly known as FTP-75 for the city driving cycle, are a series of tests defined by the US Environmental Protection Agency (EPA) to measure tailpipe emissions and fuel economy of passenger cars.
The California Smog Check Program requires vehicles that were manufactured in 1976 or later to participate in the biennial smog check program in participating counties. The program's stated aim is to reduce air pollution from vehicles by ensuring that cars with excessive emissions are repaired in accordance with federal and state guidelines. With some exceptions, gasoline-powered vehicles that are six years old or newer are not required to participate; instead, these vehicles pay a smog abatement fee for the first 6 years in place of being required to pass a smog check. The six-year exception does not apply to nonresident vehicles being registered in California for the first time, diesel vehicles 1998 model or newer and weighing 14,000 lbs or less, or specially constructed vehicles 1976 and newer. The program is a joint effort between the California Air Resources Board, the California Bureau of Automotive Repair, and the California Department of Motor Vehicles.
The California Statewide Truck and Bus Rule was initially adopted in December 2008 by the California Air Resources Board (CARB) and requires all heavy-duty diesel trucks and buses that operate in California to retrofit or replace engines in order to reduce diesel emissions. All privately and federally owned diesel-fueled trucks and buses, and privately and publicly owned school buses with a gross vehicle weight rating (GVWR) greater than 14,000 pounds, are covered by the regulation.
Mobile source air pollution includes any air pollution emitted by motor vehicles, airplanes, locomotives, and other engines and equipment that can be moved from one location to another. Many of these pollutants contribute to environmental degradation and have negative effects on human health. To prevent unnecessary damage to human health and the environment, environmental regulatory agencies such as the U.S. Environmental Protection Agency have established policies to minimize air pollution from mobile sources. Similar agencies exist at the state level. Due to the large number of mobile sources of air pollution, and their ability to move from one location to another, mobile sources are regulated differently from stationary sources, such as power plants. Instead of monitoring individual emitters, such as an individual vehicle, mobile sources are often regulated more broadly through design and fuel standards. Examples of this include corporate average fuel economy standards and laws that ban leaded gasoline in the United States. The increase in the number of motor vehicles driven in the U.S. has made efforts to limit mobile source pollution challenging. As a result, there have been a number of different regulatory instruments implemented to reach the desired emissions goals.
The Association of Global Automakers is a Washington, D.C.-based trade association and lobby group whose members include international automobile and light duty truck manufacturers that build and sell products in the United States.
Margo T. Oge is an American engineer and environmental regulator who served as the Director of the Environmental Protection Agency's Office of Radiation and Indoor Air from 1990 to 1994 and Director of the Office of Transportation and Air Quality from 1994 to 2012. Beginning in 2009, Oge lead the EPA team that authored the 2010-2016 and the 2017-2025 Light-Duty Vehicle Greenhouse Gas Emissions Standards. By 2025, these rules require automakers to half the greenhouse gas emissions of cars and light duty trucks while doubling fuel economy. These rules were the US federal government's first regulatory actions to reduce greenhouse gases.
A defeat device is any motor vehicle hardware, software, or design that interferes with or disables emissions controls under real-world driving conditions, even if the vehicle passes formal emissions testing. The term appears in the US Clean Air Act and European Union regulations, to describe anything that prevents an emissions control system from working, and applies as well to power plants or other air pollution sources, as to automobiles.
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