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Review of the 21st Century Truck Partnership (2008)

Chapter:D Vehicle Emission Regulations

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Suggested Citation:"D Vehicle Emission Regulations." National Research Council. 2008. Review of the 21st Century Truck Partnership. Washington, DC: The National Academies Press. doi: 10.17226/12258.
Suggested Citation:"D Vehicle Emission Regulations." National Research Council. 2008. Review of the 21st Century Truck Partnership. Washington, DC: The National Academies Press. doi: 10.17226/12258.
Suggested Citation:"D Vehicle Emission Regulations." National Research Council. 2008. Review of the 21st Century Truck Partnership. Washington, DC: The National Academies Press. doi: 10.17226/12258.
Suggested Citation:"D Vehicle Emission Regulations." National Research Council. 2008. Review of the 21st Century Truck Partnership. Washington, DC: The National Academies Press. doi: 10.17226/12258.
Suggested Citation:"D Vehicle Emission Regulations." National Research Council. 2008. Review of the 21st Century Truck Partnership. Washington, DC: The National Academies Press. doi: 10.17226/12258.

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Appendix D Vehicle Emission Regulations BACKGROUND EVOLUTION OF EMISSION STANDARDS Air pollution from the combustion of coal became a The control of emissions from motor vehicles began with s ­ erious problem in the 18th century with the Industrial Revo- model year 1963 when California implemented the require- lution in Europe. Concerns about air pollution in the United ment for positive crankcase ventilation that recycles the States arose in Los Angeles in the early 1940s. By 1952, the discharged blowby that had previously been vented to the city’s smog had been identified as arising from the exhaust atmosphere by the road draft tube. products of the internal combustion engine. (The irritant, Attention subsequently was focused on the control of ozone, one of the constituents of smog, is formed through exhaust emissions of motor vehicles. The first exhaust emis- complex chemical reactions between precursor emissions of sion standards were introduced in California effective with volatile organic compounds (VOCs) and oxides of nitrogen 1966 model year passenger vehicles and in the United States (NOx) in the presence of sunlight.) Subsequently, air pollu- as a whole with model year 1968 vehicles. The progressively tion from all potential sources, both vehicular and stationary, more stringent federal emission standards for light-duty was recognized as a national concern. vehicles are shown in Figure D-1. The Clean Air Act of 1963 was the beginning of federal Since the early 1960s when exhaust emissions were influence over mobile-source emissions. Subsequent amend- unregulated, the subsequent exhaust emission regulations ments established the U.S. Environmental Protection Agency by model year 2004 have resulted in the reduction of (EPA), gave EPA broad responsibility for regulating motor exhaust emissions from light-duty vehicles by the following vehicle pollution, and directed the agency to set health-based amounts: National Ambient Air Quality Standards (EPA, 1994). EPA established maximum concentrations for six “criteria pol- Hydrocarbons 99 percent reduction lutants” as indicators of air quality, above which adverse Carbon Monoxide 96 percent reduction effects on human health may occur. The six criteria pollutants Oxides of Nitrogen 99 percent reduction are ozone, carbon monoxide (CO), nitrogen dioxide, sulfur dioxide, particulate matter (PM) and lead (EPA, 2007b). To Emission standards for light-duty trucks with a gross curtail exceedance of the maximum concentrations of the vehicle weight rating (GVWR) under 8,500 lb have been criteria pollutants, EPA currently regulates emissions from somewhat higher than passenger car standards because of a variety of mobile and stationary sources. The currently differences in weight. However, in the near future, light-duty regulated emissions from motor vehicles, which are pre- truck standards will be the same as passenger car standards, dominately passenger cars, light-duty trucks, and heavy-duty as shown in Table D-1. trucks, include the following: total hydrocarbons (HCs) and Control of emissions from the engines of heavy-duty nonmethane hydrocarbons (NMHCs) or nonmethane organic trucks with GVWRs over 8,500 lb began in 1969 in gases (NMOGs), that includes oxygenated and nonoxygen- C ­ alifornia and in the United States as a whole in 1974 ated HC emissions, CO, NOx, and PM. Lead in gasoline is (Johnson, 1988). The progressively more stringent emis- also regulated to near-zero levels, which also facilitates long sion standards for heavy-duty diesel engines are shown in life for the catalytic converter in gasoline-fueled vehicles. Figure D-2 (DOE, 2006). 107

108 REVIEW OF THE 21ST CENTURY TRUCK PARTNERSHIP 25 (HC + CO/10 + NOx ) - g/mi 20 Emission Standards 15 10 5 0 1960 1970 1980 1990 2000 2010 Model Year FIGURE D-1  Historical trend in emission standards for light-duty vehicles. Individual emission standards for HC, CO, and, NO x are com- bined for illustration only. SOURCE: Data from Ehlmann and Wolff (2005). Fig D-1 FIGURE D-2  Historical trend in emission standards for heavy-duty diesel engines. Fig D-, bitmapped 2 CURRENT AND FUTURE EXHAUST EMISSION California is the only state that has been granted author- STANDARDS ity, within the original Clean Air Act, to establish separate, stricter standards for vehicle emissions, independent of the The emission standards currently in effect in the United federal government. All other states are required to comply States are promulgated by the U.S. Environmental Protec- with the federal vehicle emission standards or adopt the tion Agency (EPA) for the 49 states and by the California stricter California standards. Numerous states have adopted Air Resources Board (CARB) for the state of California. the latest CARB emission standards.

APPENDIX D 109 Passenger Car and Light-Duty Truck California Emission Standards California’s Low Emission Vehicle II (LEV II) standards Federal Emission Standards were introduced for 2004 and subsequent model years. These The Tier 2 federal passenger car emission standards, standards for all passenger cars and light-duty trucks under phased in beginning with the 2004 model year, are listed in 8,500 lb are listed in Table D-2. California categorizes the Table D-1. For the first time since the enactment of emis- standards as LEV, Ultra Low Emission Vehicle (ULEV), sion standards in the United States, the same standards are and Super Ultra Low Emission Vehicle (SULEV) standards. to be applied to both passenger cars and light-duty trucks. The manufacturer selects the appropriate category for each EPA created a “bin” system, with eight emission standard vehicle line so that the fleet average NMOG meets the CARB bins, that allows manufacturers to average emissions across mandated fleet average, which deceases with each model their fleets each year. The passenger car (PC), LDT1, LDT2, year through 2010. LDT3, and LDT4 fleet average NOx requirement is 0.07 (g/mi) at 120,000 miles for model year 2009 and beyond. Heavy-Duty Engine Emission Standards The standards listed are the emission limits at “full useful life” of 120,000 miles. The federal emissions standards for highway trucks were harmonized with California standards beginning in the model year 2004. The emission standards that apply to model year TABLE D-1  Federal Tier 2 Light-Duty Vehicle Emission Standards: Emission Limits at Full Useful Life of 120,000 Miles Mandatory for Model Year 2009 and Beyond Bin Vehicle Class NMOG (g/mi) CO (g/mi) NOx (g/mi) PM (g/mi) Mileage Requirement 8 PC/LDT1/2 0.125 4.2 0.2 0.02 120,000   LDT3/4/MDPV 0.156 4.2 0.2 0.02 120,000 7 All 0.09 4.2 0.15 0.02 120,000 6 All 0.09 4.2 0.1 0.01 120,000 5 All 0.09 4.2 0.07 0.01 120,000 4 All 0.07 2.1 0.04 0.01 120,000 3 All 0.055 2.1 0.03 0.01 120,000 2 All 0.01 2.1 0.02 0.01 120,000 1 All 0 0 0 0 120,000 NOTE: ALVW, adjusted load vehicle weight, average of curb (empty) weight and the GVWR; GVWR, gross vehicle weight rating, maximum fully loaded vehicle weight; LVW, loaded vehicle weight, nominal empty vehicle weight + 300 lb; LDT1, light-duty truck 1, up to 6,000 lb GVWR and 3,750 lb LVW; LDT2, light-duty truck 2, up to 6,000 lb GVWR and between 3,751 and 5,750 lb LVW; LDT3, light-duty truck 3, between 6,001 and 8,500 lb GVWR and between 3,751 and 5,750 lb ALVW; LDT4, light-duty truck 4, between 6,001 and 8,500 lb GVWR and over 5,750 lb ALVW; MDPV, medium-duty passenger vehicle, trucks between 8,501 and 10,000 lb GVWR; PC, passenger car. TABLE D-2  Current California LEV II Light-Duty Vehicle Emission Standards GVWR (lb) Emission Category NMOG (g/mi) CO (g/mi) NOx (g/mi) PM (g/mi) Mileage (Durability) Requirement All PCs and LEV 0.09 4.2 0.07 0.01 120,000a LDTs 8,500 lb ULEV 0.055 2.1 0.07 0.01 120,000a and less SULEV 0.01 1.0 0.02 0.01 120,000a MDV LEV 0.195 6.4 0.2 0.12 120,000a 8,501-10,000 lb ULEV 0.143 6.4 0.2 0.06 120,000a Test at ALVW SULEV 0.1 3.2 0.1 0.06 120,000a MDV LEV 0.23 7.3 0.4 0.12 120,000a 10,000-14,000 lbs ULEV 0.167 7.3 0.4 0.06 120,000a Test at ALVW SULEV 0.117 3.7 0.2 0.06 120,000a NOTE: ALVW, adjusted load vehicle weight, average of curb (empty) weight and GVWR; GVWR, gross vehicle weight rating, maximum fully loaded vehicle weight; LDT, light-duty truck; MDV, medium-duty vehicle; PC, passenger car. Other acronyms in the table are defined in Appendix E. aOptional 150,000 mileage durability requirement for partial zero emission vehicle.

110 REVIEW OF THE 21ST CENTURY TRUCK PARTNERSHIP TABLE D-3  Heavy-Duty Emission Standards: Model Year 2007 and Beyond Non-Methane Hydrocarbons (NMHC) Carbon Monoxide (CO) Nitrogen Oxides (NOx) Particulate Matter (PM) (g/bhp-hr) (g/bhp-h) (g/bhp-h) (g/bhp-h) 0.14a 15.5 0.20a 0.01 TABLE D-4  Service Classes Used by EPA Service Class Required Useful Lives of Engines Light heavy-duty diesel engine (LHDDE): 8 yr or 110,000 mi Under federal regulations, between 8,500 and 19,500 lb gross vehicle weight rating (GVWR); in California, between 14,000 and 19,500 lb GVWRa Medium heavy-duty diesel engine (MHDDE): 19,500 lb to 33,000 lb GVWR 8 yr or 185,000 mi Heavy heavy-duty diesel engine (HHDDE) (including those for diesel buses): heavier than 33,000 lb GVWR 10 yr or 435,000 mi or 23,000 hr aUnder federal light-duty Tier 2 regulations, vehicles of GVWR up to 10,000 lb used for personal transportation are reclassified as medium-duty passenger vehicles (MDPV—primarily SUVs and passenger vans) and are subject to light-duty vehicle legislation. TABLE D-5  Additional Emission Requirements Test Limits Supplemental Emission Test (SET) Federal Test Procedure (FTP) Standards Not-to-exceed (NTE) Limits 1.5 × FTP Standards 2007 and later heavy-duty highway engines are listed in For Further Information Table D-3. Federal regulations do not require that complete The preceding review of current and future emission stan- heavy-duty diesel vehicles be chassis-certified; instead dards is intended to provide an overview of the key aspects requiring the certification of their engines. Consequently, the of current and future emission standards that either are emissions standards are expressed in grams per brake horse- applicable to the 21CTP or provide background information power hours (g/bhp-hr) and require emission testing over the to aid in evaluating the Partnership. For a complete under- transient Federal Test Procedure (FTP) engine dynamometer standing of past and present emission standards highlighted cycle. Table D-4 lists the useful lives of the engines in various in this section, the reader is directed to the actual regulations service classes; the required useful life of Class 8 engines as promulgated by the U.S. Environmental Protection Agency required by the emission standards is 435,000 miles, or 10 and the California Air Resources Board. years, or 22,000 hours. Additional emission testing requirements, first introduced in 1998, are shown in Table D-5 and include the ­Supplemental EMISSION STANDARDS NOT ADDRESSED Emission Test (SET) and Not-to-Exceed (NTE) limits. BY THE 21CTP The SET is a 13-mode steady-state test that was intro- duced to help ensure that heavy-duty engine emissions are Evaporative Emissions controlled during steady-state type driving, such as a line- Evaporative emissions, produced from the evaporation of haul truck operating on a freeway. fuel, have been a large contributor to urban smog, because The NTE limits have been introduced as an additional the heavier molecules of unburned fuel stay closer to ground instrument to ensure that heavy-duty engine emissions are level. Fuel evaporates from a vehicle in the following controlled over the full range of speed and load combina- ways: by gas tank venting, from running losses, and from tions commonly experienced in use. The NTE requirement refueling losses. Evaporative emission standards were first establishes an area (the “NTE zone”) under the torque curve promulgated for 1971 model year vehicles when charcoal of an engine where emissions must not exceed a specified canisters were introduced to trap gasoline vapors. These value for any of the regulated pollutants.

APPENDIX D 111 TABLE D-6  Timetable for Implementation of On-Board Diagnostic (OBD) II Systems for Heavy-Duty Vehicles (more than 14,000 lb GVWR) Regulatory Body Model Year Comments California Air Resources Board (CARB) 2007 Basic Engine Manufacturer Diagnostic (EMD) system CARB 2010 Proposed Comprehensive OBD II system U.S. Environmental Protection Agency 2010 Proposed Notice of Proposed Rule standards become more stringent in recent years. The most Although OBD II is a key element in maintaining the stringent evaporative emission standards have recently been stringent emission levels that are the focus of the 21CTP, introduced for gasoline-fueled vehicles. California currently the development and application of OBD II are not included has an optional zero evaporative emission standard, which is in the scope of this partnership and are not discussed further one of the requirements for certifying a vehicle with SULEV in this report. exhaust emissions as a partial zero emission vehicle. In recognition of the high temperatures that diesel fuel Defeat Devices can reach in modern common rail fuel systems, evaporative emission standards for diesel fuel vehicles have also been Manufacturers must ensure that vehicle emission control adopted. Because technology to control diesel evaporative systems operate in use as they do on the prescribed test emissions are not considered to be a significant issue, these cycles. If, without properly informing EPA, an emission emissions are not included in the scope of 21CTP and will control system operates differently when in use, the emis- not be discussed in this report. sion control system is considered “defeated” and a “defeat device” is present. EPA may seek judicial penalties for each vehicle sold containing a defeat device (EPA, 2007a). On-Board Diagnostic II (OBD II) System The On-Board Diagnostic II (OBD II) system was phased REFERENCES in on light-duty vehicles beginning with the 1994 model year vehicles. The purpose of the on-board diagnostic system on Dieselnet. 2005. California adopts OBD requirements for heavy-duty engines. July 22. Available at vehicles is to ensure the emission control system and other 07carb.php. Accessed May 29, 2007. engine-related components are operating properly. When the DOE (U.S. Department of Energy). 2006. 21st Century Truck Partnership OBD II system detects a problem, a corresponding “Diag- Roadmap and Technical White Papers. Doc. No. 21CTP-003. Washing- nostic Trouble Code” (DTC) is stored in the computer’s ton, D.C. December. memory and a special light on the instrument cluster called Ehlmann, James, and George Wolff. 2005. Automobile Emissions—The Road Toward Zero. Air and Waste Management Association. January. a Malfunction Indicator Lamp (MIL) is illuminated. EPA (U.S. Environmental Protection Agency). 1994. Fact Sheet OMS-12, The OBD II system is intended to ensure proper emission August. system operation for every vehicle throughout its lifetime, EPA. 2006. Regulatory Announcement: Proposed Rule on OBD for Heavy and notifies the driver of a problem before the vehicle’s emis- Duty Engines. EPA 420-F-06-058. Washington, D.C.: Office of Trans- sions have increased significantly. portation and Air Quality. April. EPA. 2007a. Clean Air Act Enforcement. Available at http://www.epa. Heavy-duty engine OBD II, also referred to as the engine gov/compliance/civil/caa. Accessed September 7, 2007. manufacturer diagnostic system, is similar to the light duty EPA. 2007b. Green Book [Non-attainment Areas under the Clean Air Act of OBD II system, except that the monitors are not required 1972 as Amended]. Available at to be tied to the emission standards (Dieselnet, 2005; EPA, index.html. Accessed June 14, 2007. 2006). Johnson, J. H. 1988. Automotive Emissions. P. 45 in Air Pollution, the Automobile, and Public Health. Washington, D.C.: National Academy The timetable for implementation of OBD II for heavy- Press. duty vehicles as shown in Table D-6.

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The 21st Century Truck Partnership (21CTP), a cooperative research and development partnership formed by four federal agencies with 15 industrial partners, was launched in the year 2000 with high hopes that it would dramatically advance the technologies used in trucks and buses, yielding a cleaner, safer, more efficient generation of vehicles.

Review of the 21st Century Truck Partnership critically examines and comments on the overall adequacy and balance of the 21CTP. The book reviews how well the program has accomplished its goals, evaluates progress in the program, and makes recommendations to improve the likelihood of the Partnership meeting its goals.

Key recommendations of the book include that the 21CTP should be continued, but the future program should be revised and better balanced. A clearer goal setting strategy should be developed, and the goals should be clearly stated in measurable engineering terms and reviewed periodically so as to be based on the available funds.

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