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The following definitions apply to this part. The definitions apply to all subparts unless we note otherwise. All undefined terms have the meaning the Act gives to them. The definitions follow:
Adjustable parameter has the meaning given in 40 CFR 1068.30.
Adjustable parameter means any device, system, or element of design that someone can adjust (including those which are difficult to access) and that, if adjusted, may affect measured or modeled emissions (as applicable). You may ask us to exclude a parameter that is difficult to access if it cannot be adjusted to affect emissions without significantly degrading vehicle performance, or if you otherwise show us that it will not be adjusted in a way that affects emissions during in-use operation.
Adjusted Loaded Vehicle Weight means the numerical average of vehicle curb weight and GVWR.
Advanced technology means vehicle technology certified under 40 CFR 86.1819-14(k)(7), 40 CFR 1036.615, or §1037.615.
Aftertreatment means relating to a catalytic converter, particulate filter, or any other system, component, or technology mounted downstream of the exhaust valve (or exhaust port) whose design function is to decrease emissions in the vehicle exhaust before it is exhausted to the environment. Exhaust gas recirculation (EGR) and turbochargers are not aftertreatment.
Aircraft means any vehicle capable of sustained air travel more than 100 feet off the ground.
Alcohol-fueled vehicle means a vehicle that is designed to run using an alcohol fuel. For purposes of this definition, alcohol fuels do not include fuels with a nominal alcohol content below 25 percent by volume.
Alternative fuel conversion has the meaning given for clean alternative fuel conversion in 40 CFR 85.502.
Ambulance has the meaning given in 40 CFR 86.1803.
Amphibious vehicle means a motor vehicle that is also designed for operation on water. Note that high ground clearance that enables a vehicle to drive through water rather than floating on the water does not make a vehicle amphibious.
A to B testing means testing performed in pairs to allow comparison of two vehicles or other test articles. Back-to-back tests are performed on Article A and Article B, changing only the variable(s) of interest for the two tests.
Automatic tire inflation system means a pneumatically or electronically activated system installed on a vehicle to maintain tire pressure at a preset level. These systems eliminate the need to manually inflate tires. Note that this is different than a tire pressure monitoring system, which we define separately in this section.
Automated manual transmission (AMT) means a transmission that operates mechanically similar to a manual transmission, except that an automated clutch actuator controlled by the onboard computer disengages and engages the drivetrain instead of a human driver. An automated manual transmission does not include a torque converter or a clutch pedal controllable by the driver.
Automatic transmission (AT) means a transmission with a torque converter (or equivalent) that uses computerize or other internal controls to shift gears in response to a single driver input for controlling vehicle speed.. Note that automatic manual transmissions are not automatic transmissions because they do not include torque converters.
Auxiliary emission control device means any element of design that senses temperature, motive speed, engine speed (r/min), transmission gear, or any other parameter for the purpose of activating, modulating, delaying, or deactivating the operation of any part of the emission control system.
Auxiliary power unit means a device installed on a vehicle that uses an engine to provide power for purposes other than to (directly or indirectly) propel the vehicle.
Averaging set has the meaning given in §1037.701.
Axle ratio or Drive axle ratio, ka, means the dimensionless number representing the angular speed of the transmission output shaft divided by the angular speed of the drive axle.
Basic vehicle frontal area means the area enclosed by the geometric projection of the basic vehicle along the longitudinal axis onto a plane perpendicular to the longitudinal axis of the vehicle, including tires but excluding mirrors and air deflectors. Note that in certain cases, this may refer to the combined area of a tractor and trailer.
Battery electric vehicle means a motor vehicle powered solely by an electric motor where energy for the motor is supplied by one or more batteries that receive power from an external source of electricity. Note that this definition does not include hybrid vehicles or plug-in hybrid electric vehicles.
Bus means a heavy-duty vehicle designed to carry more than 15 passengers. Buses may include coach buses, school buses, and urban transit buses.
Calibration means the set of specifications and tolerances specific to a particular design, version, or application of a component or assembly capable of functionally describing its operation over its working range.
Carryover means relating to certification based on emission data generated from an earlier model year.
Coach bus means a bus designed for inter-city passenger transport. Buses with features to accommodate standing passengers are not coach buses.
Concrete mixer means a heavy-duty vehicle designed to mix and transport concrete in a permanently mounted revolving drum.
Certification means relating to the process of obtaining a certificate of conformity for a vehicle family that complies with the emission standards and requirements in this part.
Certified emission level means the highest deteriorated emission level in a vehicle subfamily for a given pollutant from either transient or steady-state testing.
Charge-depleting has the meaning given in 40 CFR 1066.1001.
Charge-sustaining has the meaning given in 40 CFR 1066.1001.
Class means relating to GVWR classes, as follows:
(1) Class 2b means relating to heavy-duty motor vehicles at or below 10,000 pounds GVWR.
(2) Class 3 means relating to heavy-duty motor vehicles above 10,000 pounds GVWR but at or below 14,000 pounds GVWR.
(3) Class 4 means relating to heavy-duty motor vehicles above 14,000 pounds GVWR but at or below 16,000 pounds GVWR.
(4) Class 5 means relating to heavy-duty motor vehicles above 16,000 pounds GVWR but at or below 19,500 pounds GVWR.
(5) Class 6 means relating to heavy-duty motor vehicles above 19,500 pounds GVWR but at or below 26,000 pounds GVWR.
(6) Class 7 means relating to heavy-duty motor vehicles above 26,000 pounds GVWR but at or below 33,000 pounds GVWR.
(7) Class 8 means relating to heavy-duty motor vehicles above 33,000 pounds GVWR.
Complete vehicle has the meaning given in the definition for vehicle in this section.
Compression-ignition has the meaning given in §1037.101.
Date of manufacture means the date on which the certifying vehicle manufacturer completes its manufacturing operations, except as follows:
(1) Where the certificate holder is an engine manufacturer that does not manufacture the chassis, the date of manufacture of the vehicle is based on the date assembly of the vehicle is completed.
(2) We may approve an alternate date of manufacture based on the date on which the certifying (or primary) manufacturer completes assembly at the place of main assembly, consistent with the provisions of §1037.601 and 49 CFR 567.4.
Day cab means a type of tractor cab that is not a sleeper cab or a heavy-haul tractor cab.
Designated Compliance Officer means one of the following:
(1) For compression-ignition engines, Designated Compliance Officer means Director, Diesel Engine Compliance Center, U.S. Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; complianceinfo@epa.gov; www.epa.gov/ve-certification.
(2) For spark-ignition engines, Designated Compliance Officer means Director, Gasoline Engine Compliance Center, U.S. Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; complianceinfo@epa.gov; www.epa.gov/ve-certification.
Deteriorated emission level means the emission level that results from applying the appropriate deterioration factor to the official emission result of the emission-data vehicle. Note that where no deterioration factor applies, references in this part to the deteriorated emission level mean the official emission result.
Deterioration factor means the relationship between the highest emissions during the useful life and emissions at the low-hour test point, expressed in one of the following ways:
(1) For multiplicative deterioration factors, the ratio of the highest emissions to emissions at the low-hour test point.
(2) For additive deterioration factors, the difference between the highest emissions and emissions at the low-hour test point.
Diesel exhaust fluid (DEF) means a liquid reducing agent (other than the engine fuel) used in conjunction with selective catalytic reduction to reduce NOX emissions. Diesel exhaust fluid is generally understood to be an aqueous solution of urea conforming to the specifications of ISO 22241.
Drayage tractor means a tractor that is intended for service in a port or intermodal railyard, with multiple design features consistent with that intent, such as a cab with only a single seat, rear cab entry, a raisable fifth wheel, a solid-mounted rear suspension, and a maximum speed at or below 54 mi/hr.
Drive idle means idle operation during which the vehicle operator remains in the vehicle cab, as evidenced by engaging the brake or clutch pedals, or by other indicators we approve.
Driver model means an automated controller that simulates a person driving a vehicle.
Dual-clutch transmission (DCT) means a transmission that operates similar to an automated manual transmission, but with two clutches that allow the transmission to maintain positive torque to the drive axle during a shift.
Dual-fuel means relating to a vehicle or engine designed for operation on two different fuels but not on a continuous mixture of those fuels. For purposes of this part, such a vehicle or engine remains a dual-fuel vehicle or engine even if it is designed for operation on three or more different fuels.
Electronic control module has the meaning given in 40 CFR 1065.1001.
Emergency vehicle means a vehicle that is an ambulance or a fire truck.
Emission control system means any device, system, or element of design that controls or reduces the emissions of regulated pollutants from a vehicle.
Emission-data component means a vehicle component that is tested for certification. This includes vehicle components tested to establish deterioration factors.
Emission-data vehicle means a vehicle (or vehicle component) that is tested for certification. This includes vehicles tested to establish deterioration factors.
Emission-related component has the meaning given in 40 CFR part 1068, appendix A.
Emission-related maintenance means maintenance that substantially affects emissions or is likely to substantially affect emission deterioration.
Excluded means relating to vehicles that are not subject to some or all of the requirements of this part as follows:
(1) A vehicle that has been determined not to be a “motor vehicle” is excluded from this part.
(2) Certain vehicles are excluded from the requirements of this part under §1037.5.
(3) Specific regulatory provisions of this part may exclude a vehicle generally subject to this part from one or more specific standards or requirements of this part.
Exempted has the meaning given in 40 CFR 1068.30. Note that exempted vehicles are not considered to be excluded.
Extended idle means tractor idle operation during which the engine is operating to power accessories for a sleeper compartment or other passenger compartment. Although the vehicle is generally parked during extended idle, the term “parked idle” generally refers to something different than extended idle.
Family emission limit (FEL) means an emission level declared by the manufacturer to serve in place of an otherwise applicable emission standard under the ABT program in subpart H of this part. The family emission limit must be expressed to the same number of decimal places as the emission standard it replaces. Note that an FEL may apply as a “subfamily” emission limit.
Final drive ratio, kd, means the dimensionless number representing the angular speed of the transmission input shaft divided by the angular speed of the drive axle when the vehicle is operating in its highest available gear. The final drive ratio is the transmission gear ratio (in the highest available gear) multiplied by the drive axle ratio.
Fire truck has the meaning given in 40 CFR 86.1803.
Flexible-fuel means relating to an engine designed for operation on any mixture of two or more different fuels.
Fuel cell electric vehicle means a motor vehicle powered solely by an electric motor where energy for the motor is supplied by hydrogen fuel cells. Fuel cell electric vehicles may include energy storage from the fuel cells or from regenerative braking in a battery.
Fuel system means all components involved in transporting, metering, and mixing the fuel from the fuel tank to the combustion chamber(s), including the fuel tank, fuel pump, fuel filters, fuel lines, carburetor or fuel-injection components, and all fuel-system vents. It also includes components for controlling evaporative emissions, such as fuel caps, purge valves, and carbon canisters.
Fuel type means a general category of fuels such as diesel fuel or natural gas. There can be multiple grades within a single fuel type, such as high-sulfur or low-sulfur diesel fuel.
Gaseous fuel means a fuel that has a boiling point below 20°C.
Gear ratio or Transmission gear ratio, kg,means the dimensionless number representing the angular speed of the transmission's input shaft divided by the angular speed of the transmission's output shaft when the transmission is operating in a specific gear.
Glider kit means either of the following:
(1) A new vehicle that is incomplete because it lacks an engine, transmission, and/or axle(s).
(2) Any other new equipment that is substantially similar to a complete motor vehicle and is intended to become a complete motor vehicle with a previously used engine (including a rebuilt or remanufactured engine). For example, incomplete heavy-duty tractor assemblies that are produced on the same assembly lines as complete tractors and that are made available to secondary vehicle manufacturers to complete assembly by installing used/remanufactured engines, transmissions and axles are glider kits.
Glider vehicle means a new motor vehicle produced from a glider kit, or otherwise produced as a new motor vehicle with a with a used/remanufactured engine.
Good engineering judgment has the meaning given in 40 CFR 1068.30. See 40 CFR 1068.5 for the administrative process we use to evaluate good engineering judgment.
Greenhouse gas Emissions Model (GEM) means the GEM simulation tool described in §1037.520 (incorporated by reference, see §1037.810).
Gross axle weight rating (GAWR) means the value specified by the vehicle manufacturer as the maximum weight of a loaded axle or set of axles, consistent with good engineering judgment.
Gross combination weight rating (GCWR) means the value specified by the vehicle manufacturer as the maximum weight of a loaded vehicle and trailer, consistent with good engineering judgment. For example, compliance with SAE J2807 is generally considered to be consistent with good engineering judgment, especially for Class 3 and smaller vehicles.
Gross vehicle weight rating (GVWR) means the value specified by the vehicle manufacturer as the maximum design loaded weight of a single vehicle, consistent with good engineering judgment.
Heavy-duty engine means any engine used for (or for which the engine manufacturer could reasonably expect to be used for) motive power in a heavy-duty vehicle.
Heavy-duty vehicle means any motor vehicle that has a GVWR above 8,500 pounds. An incomplete vehicle is also a heavy-duty vehicle if it has a curb weight above 6,000 pounds or a basic vehicle frontal area greater than 45 square feet.
Heavy-haul tractor means a tractor with GCWR greater than or equal to 120,000 pounds. A heavy-haul tractor is not a vocational tractor in Phase 2 and later.
High-strength steel has the meaning given in §1037.520.
Hybrid has the meaning given in 40 CFR 1036.801. Note that a hybrid vehicle is a vehicle with a hybrid engine or other hybrid powertrain. This includes plug-in hybrid electric vehicles.
Hybrid engine or hybrid powertrain means an engine or powertrain that includes energy storage features other than a conventional battery system or conventional flywheel. Supplemental electrical batteries and hydraulic accumulators are examples of hybrid energy storage systems. Note other examples of systems that qualify as hybrid engines or powertrains are systems that recover kinetic energy and use it to power an electric heater in the aftertreatment. Note that certain provisions in this part treat hybrid engines and hybrid powertrains intended for vehicles that include regenerative braking different than those intended for vehicles that do not include regenerative braking.
Hybrid vehicle means a vehicle that includes energy storage features (other than a conventional battery system or conventional flywheel) in addition to an internal combustion engine or other engine using consumable chemical fuel. Supplemental electrical batteries and hydraulic accumulators are examples of hybrid energy storage systems. Note other examples of systems that qualify as hybrid engines or powertrains are systems that recover kinetic energy and use it to power an electric heater in the aftertreatment. Note that certain provisions in this part treat hybrid vehicles that include regenerative braking different than those that do not include regenerative braking.
Hydrocarbon (HC) means the hydrocarbon group on which the emission standards are based for each fuel type. For alcohol-fueled vehicles, HC means nonmethane hydrocarbon equivalent (NMHCE) for exhaust emissions and total hydrocarbon equivalent (THCE) for evaporative emissions. For all other vehicles, HC means nonmethane hydrocarbon (NMHC) for exhaust emissions and total hydrocarbon (THC) for evaporative emissions.
Identification number means a unique specification (for example, a model number/serial number combination) that allows someone to distinguish a particular vehicle from other similar vehicles.
Idle operation means any operation other than PTO operation during which the vehicle speed is zero. Idle operation may be “Drive idle” or “Parked idle” (as defined in this section).
Incomplete vehicle has the meaning given in the definition of vehicle in this section.
Innovative technology means technology certified under §1037.610 (also described as “off-cycle technology”).
Light-duty truck has the meaning given in 40 CFR 86.1803-01.
Light-duty vehicle has the meaning given in 40 CFR 86.1803-01.
Low-mileage means relating to a vehicle with stabilized emissions and represents the undeteriorated emission level. This would generally involve approximately 4000 miles of operation.
Low rolling resistance tire means a tire on a vocational vehicle with a TRRL at or below of 7.7 N/kN, a steer tire on a tractor with a TRRL at or below 7.7 N/kN, a drive tire on a tractor with a TRRL at or below 8.1 N/kN.
Manual transmission (MT) means a transmission that requires the driver to shift the gears and manually engage and disengage the clutch.
Manufacture means the physical and engineering process of designing, constructing, and/or assembling a vehicle.
Manufacturer has the meaning given in section 216(1) of the Act. In general, this term includes any person who manufactures or assembles a vehicle (including an incomplete vehicle) for sale in the United States or otherwise introduces a new motor vehicle into commerce in the United States. This includes importers who import vehicles for resale, entities that manufacture glider kits, and entities that assemble glider vehicles.
Medium-duty passenger vehicle (MDPV) has the meaning given in 40 CFR 86.1803.
Model year means one of the following for compliance with this part. Note that manufacturers may have other model year designations for the same vehicle for compliance with other requirements or for other purposes:
(1) For vehicles with a date of manufacture on or after January 1, 2021, model year means the manufacturer's annual new model production period based on the vehicle's date of manufacture, where the model year is the calendar year corresponding to the date of manufacture, except as follows:
(i) The vehicle's model year may be designated as the year before the calendar year corresponding to the date of manufacture if the engine's model year is also from an earlier year. You may ask us to extend your prior model year certificate to include such vehicles. Note that §1037.601(a)(2) limits the extent to which vehicle manufacturers may install engines built in earlier calendar years.
(ii) The vehicle's model year may be designated as the year after the calendar year corresponding to the vehicle's date of manufacture. For example, a manufacturer may produce a new vehicle by installing the engine in December 2023 and designating it as a model year 2024 vehicle.
(2) For Phase 1 vehicles with a date of manufacture before January 1, 2021, model year means the manufacturer's annual new model production period, except as restricted under this definition and 40 CFR part 85, subpart X. It must include January 1 of the calendar year for which the model year is named, may not begin before January 2 of the previous calendar year, and it must end by December 31 of the named calendar year. The model year may be set to match the calendar year corresponding to the date of manufacture.
(i) The manufacturer who holds the certificate of conformity for the vehicle must assign the model year based on the date when its manufacturing operations are completed relative to its annual model year period. In unusual circumstances where completion of your assembly is delayed, we may allow you to assign a model year one year earlier, provided it does not affect which regulatory requirements will apply.
(ii) Unless a vehicle is being shipped to a secondary vehicle manufacturer that will hold the certificate of conformity, the model year must be assigned prior to introduction of the vehicle into U.S. commerce. The certifying manufacturer must redesignate the model year if it does not complete its manufacturing operations within the originally identified model year. A vehicle introduced into U.S. commerce without a model year is deemed to have a model year equal to the calendar year of its introduction into U.S. commerce unless the certifying manufacturer assigns a later date.
Motor home has the meaning given in 49 CFR 571.3.
Motor vehicle has the meaning given in 40 CFR 85.1703.
Multi-Purpose means relating to the Multi-Purpose duty cycle as specified in §1037.510.
Neat has the meaning given in 40 CFR 1065.1001.
Neutral coasting means a vehicle technology that automatically puts the transmission in neutral when the when operator demand is zero while the vehicle is in motion, such as driving downhill.
Neutral idle means a vehicle technology that automatically puts the transmission in neutral when the vehicle is stopped, as described in §1037.660(a).
New motor vehicle has the meaning given in the Act. It generally means a motor vehicle meeting the criteria of either paragraph (1) or (2) of this definition. New motor vehicles may be complete or incomplete.
(1) A motor vehicle for which the ultimate purchaser has never received the equitable or legal title is a new motor vehicle. This kind of vehicle might commonly be thought of as “brand new” although a new motor vehicle may include previously used parts. For example, vehicles commonly known as “glider kits,” “glider vehicles,” or “gliders” are new motor vehicles. Under this definition, the vehicle is new from the time it is produced until the ultimate purchaser receives the title or places it into service, whichever comes first.
(2) An imported heavy-duty motor vehicle originally produced after the 1969 model year is a new motor vehicle.
Noncompliant vehicle means a vehicle that was originally covered by a certificate of conformity, but is not in the certified configuration or otherwise does not comply with the conditions of the certificate.
Nonconforming vehicle means a vehicle not covered by a certificate of conformity that would otherwise be subject to emission standards.
Nonmethane hydrocarbon (NMHC) means the sum of all hydrocarbon species except methane, as measured according to 40 CFR part 1065.
Nonmethane hydrocarbon equivalent (NMHCE) has the meaning given in 40 CFR 1065.1001.
Off-cycle technology means technology certified under §1037.610 (also described as “innovative technology”).
Official emission result means the measured emission rate for an emission-data vehicle on a given duty cycle before the application of any required deterioration factor, but after the applicability of regeneration adjustment factors.
Owners manual means a document or collection of documents prepared by the vehicle manufacturer for the owners or operators to describe appropriate vehicle maintenance, applicable warranties, and any other information related to operating or keeping the vehicle. The owners manual is typically provided to the ultimate purchaser at the time of sale. The owners manual may be in paper or electronic format.
Oxides of nitrogen has the meaning given in 40 CFR 1065.1001.
Parked idle means idle operation during which the transmission is set to park, or the transmission is in neutral with the parking brake engaged. Although this idle may occur for extended periods, the term “extended idle” refers to tractor operation in which the engine is operating to power accessories for a sleeper compartment or other passenger compartment.
Particulate trap means a filtering device that is designed to physically trap all particulate matter above a certain size.
Percent (%) has the meaning given in 40 CFR 1065.1001. Note that this means percentages identified in this part are assumed to be infinitely precise without regard to the number of significant figures. For example, one percent of 1,493 is 14.93.
Petroleum means gasoline or diesel fuel or other fuels normally derived from crude oil. This does not include methane or liquefied petroleum gas.
Phase 1 means relating to the Phase 1 standards specified in §1037.105 and 1037.106. For example, a vehicle subject to the Phase 1 standards is a Phase 1 vehicle.
Phase 2 means relating to the Phase 2 standards specified in §1037.105 and 1037.106.
Phase 3 means relating to the Phase 3 standards specified in §1037.105 and 1037.106.
Placed into service means put into initial use for its intended purpose, excluding incidental use by the manufacturer or a dealer.
Plug-in hybrid electric vehicle means a hybrid vehicle that has the capability to charge one or more batteries from an external source of electricity while the vehicle is parked.
Power take-off (PTO) means a secondary engine shaft (or equivalent) that provides substantial auxiliary power for purposes unrelated to vehicle propulsion or normal vehicle accessories such as air conditioning, power steering, and basic electrical accessories. A typical PTO uses a secondary shaft on the engine to transmit power to a hydraulic pump that powers auxiliary equipment, such as a boom on a bucket truck. You may ask us to consider other equivalent auxiliary power configurations (such as those with hybrid vehicles) as power take-off systems.
Preliminary approval means approval granted by an authorized EPA representative prior to submission of an application for certification, consistent with the provisions of §1037.210.
Rechargeable Energy Storage System (RESS) has the meaning given in 40 CFR 1065.1001.
Refuse hauler means a heavy-duty vehicle whose primary purpose is to collect, compact, and transport solid waste, including recycled solid waste.
Regional means relating to the Regional duty cycle as specified in §1037.510.
Regulatory subcategory has the meaning given in §1037.230.
Relating to as used in this section means relating to something in a specific, direct manner. This expression is used in this section only to define terms as adjectives and not to broaden the meaning of the terms.
Revoke has the meaning given in 40 CFR 1068.30.
Roof height means the maximum height of a vehicle (rounded to the nearest inch), excluding narrow accessories such as exhaust pipes and antennas, but including any wide accessories such as roof fairings. Measure roof height of the vehicle configured to have its maximum height that will occur during actual use, with properly inflated tires and no driver, passengers, or cargo onboard. Roof height may also refer to the following categories:
(1) Low-roof means relating to a vehicle with a roof height of 120 inches or less.
(2) Mid-roof means relating to a vehicle with a roof height of 121 to 147 inches.
(3) High-roof means relating to a vehicle with a roof height of 148 inches or more.
Round has the meaning given in 40 CFR 1065.1001.
Scheduled maintenance means adjusting, repairing, removing, disassembling, cleaning, or replacing components or systems periodically to keep a part or system from failing, malfunctioning, or wearing prematurely. It also may mean actions you expect are necessary to correct an overt indication of failure or malfunction for which periodic maintenance is not appropriate.
School bus has the meaning given in 49 CFR 571.3.
Secondary vehicle manufacturer anyone that produces a vehicle by modifying a complete vehicle or completing the assembly of a partially complete vehicle. For the purpose of this definition, “modifying” generally does not include making changes that do not remove a vehicle from its original certified configuration. However, custom sleeper modifications and alternative fuel conversions that change actual vehicle aerodynamics are considered to be modifications, even if they are permitted without recertification. This definition applies whether the production involves a complete or partially complete vehicle and whether the vehicle was previously certified to emission standards or not. Manufacturers controlled by the manufacturer of the base vehicle (or by an entity that also controls the manufacturer of the base vehicle) are not secondary vehicle manufacturers; rather, both entities are considered to be one manufacturer for purposes of this part.
Sleeper cab means a type of tractor cab that has a compartment behind the driver's seat intended to be used by the driver for sleeping, and is not a heavy-haul tractor cab. This includes cabs accessible from the driver's compartment and those accessible from outside the vehicle.
Small manufacturer means a manufacturer meeting the small business criteria specified in 13 CFR 121.201 for heavy-duty truck manufacturing (NAICS code 336120). The employee limit applies to the total number employees for all affiliated companies (as defined in 40 CFR 1068.30).
Spark-ignition has the meaning given in §1037.101.
Standard payload means the payload assumed for each vehicle, in tons, for modeling and calculating emission credits, as follows:
(1) For vocational vehicles:
(i) 2.85 tons for Light HDV.
(ii) 5.6 tons for Medium HDV.
(iii) 7.5 tons for Heavy HDV.
(2) For tractors:
(i) 12.5 tons for Class 7.
(ii) 19 tons for Class 8, other than heavy-haul tractors.
(iii) 43 tons for heavy-haul tractors.
Standard trailer has the meaning given in §1037.501.
State of certified energy (SOCE) means the measured or onboard UBE performance at a specific point in its lifetime, expressed as a percentage of the certified usable battery energy.
Stop-start means a vehicle technology that automatically turns the engine off when the vehicle is stopped, as described in §1037.660(a).
Suspend has the meaning given in 40 CFR 1068.30.
Test sample means the collection of vehicles or components selected from the population of a vehicle family for emission testing. This may include testing for certification, production-line testing, or in-use testing.
Test vehicle means a vehicle in a test sample.
Test weight means the vehicle weight used or represented during testing.
Tire pressure monitoring system (TPMS) is a vehicle system that monitors air pressure in each tire and alerts the operator when tire pressure falls below a specified value.
Tire rolling resistance level (TRRL) means a value with units of N/kN that represents the rolling resistance of a tire configuration. TRRLs are used as modeling inputs under §§1037.515 and 1037.520. Note that a manufacturer may use the measured value for a tire configuration's coefficient of rolling resistance, or assign some higher value.
Ton means a short ton, which is exactly 2000 pounds.
Total hydrocarbon has the meaning given in 40 CFR 1065.1001. This generally means the combined mass of organic compounds measured by the specified procedure for measuring total hydrocarbon, expressed as a hydrocarbon with an atomic hydrogen-to-carbon ratio of 1.85:1.
Total hydrocarbon equivalent has the meaning given in 40 CFR 1065.1001. This generally means the sum of the carbon mass contributions of non-oxygenated hydrocarbon, alcohols and aldehydes, or other organic compounds that are measured separately as contained in a gas sample, expressed as exhaust hydrocarbon from petroleum-fueled vehicles. The atomic hydrogen-to-carbon ratio of the equivalent hydrocarbon is 1.85:1.
Tractor has the meaning given for “truck tractor” in 49 CFR 571.3. This includes most heavy-duty vehicles specifically designed for the primary purpose of pulling trailers, but does not include vehicles designed to carry other loads. For purposes of this definition “other loads” would not include loads carried in the cab, sleeper compartment, or toolboxes. Examples of vehicles that are similar to tractors but that are not tractors under this part include dromedary tractors, automobile haulers, straight trucks with trailers hitches, and tow trucks. Note that the provisions of this part that apply for tractors do not apply for tractors that are classified as vocational tractors under §1037.630.
Trailer means a piece of equipment designed for carrying cargo and for being drawn by a tractor when coupled to the tractor's fifth wheel.
Ultimate purchaser means, with respect to any new vehicle, the first person who in good faith purchases such new vehicle for purposes other than resale.
United States has the meaning given in 40 CFR 1068.30.
Upcoming model year means for a vehicle family the model year after the one currently in production.
Urban means relating to the Urban duty cycle as specified in §1037.510.
U.S.-directed production volume means the number of vehicle units, subject to the requirements of this part, produced by a manufacturer for which the manufacturer has a reasonable assurance that sale was or will be made to ultimate purchasers in the United States.
Usable battery energy (UBE) means the energy the battery supplies from the start of the certification test procedure until the applicable break-off criterion. This part depends on certified and aged values of UBE to set battery monitoring requirements as described in §1037.115(f).
Useful life means the period during which a vehicle is required to comply with all applicable emission standards.
Vehicle means equipment intended for use on highways that meets at least one of the criteria of paragraph (1) of this definition, as follows:
(1) The following equipment are vehicles:
(i) A piece of equipment that is intended for self-propelled use on highways becomes a vehicle when it includes at least an engine, a transmission, and a frame. (Note: For purposes of this definition, any electrical, mechanical, and/or hydraulic devices attached to engines for the purpose of powering wheels are considered to be transmissions.)
(ii) A piece of equipment that is intended for self-propelled use on highways becomes a vehicle when it includes a passenger compartment attached to a frame with one or more axles.
(2) Vehicles may be complete or incomplete vehicles as follows:
(i) A complete vehicle is a functioning vehicle that has the primary load carrying device or container (or equivalent equipment) attached when it is first sold as a vehicle. Examples of equivalent equipment would include fifth wheel trailer hitches, firefighting equipment, and utility booms.
(ii) An incomplete vehicle is a vehicle that is not a complete vehicle. Incomplete vehicles may also be cab-complete vehicles. This may include vehicles sold to secondary vehicle manufacturers.
(iii) You may ask us to allow you to certify a vehicle as incomplete if you manufacture the engines and sell the unassembled chassis components, as long as you do not produce and sell the body components necessary to complete the vehicle.
Vehicle configuration means a unique combination of vehicle hardware and calibration (related to measured or modeled emissions) within a vehicle family. Vehicles with hardware or software differences, but that have no hardware or software differences related to measured or modeled emissions may be included in the same vehicle configuration. Note that vehicles with hardware or software differences related to measured or modeled emissions are considered to be different configurations even if they have the same GEM inputs and FEL. Vehicles within a vehicle configuration differ only with respect to normal production variability or factors unrelated to measured or modeled emissions.
Vehicle family has the meaning given in §1037.230.
Vehicle service class has the meaning given in §1037.140. The different vehicle service classes are Light HDV, Medium HDV, and Heavy HDV.
Vehicle subfamily or subfamily means a subset of a vehicle family including vehicles subject to the same FEL(s).
Vocational tractor means a vehicle classified as a vocational tractor under §1037.630.
Vocational vehicle means relating to a vehicle subject to the standards of §1037.105 (including vocational tractors).
Void has the meaning given in 40 CFR 1068.30.
Volatile liquid fuel means any fuel other than diesel or biodiesel that is a liquid at atmospheric pressure and has a Reid Vapor Pressure higher than 2.0 pounds per square inch.
We (us, our) means the Administrator of the Environmental Protection Agency and any authorized representatives.
[86 FR 34491, Jun. 29, 2021; 88 FR 4653, Jan. 24, 2023; 89 FR 29790, Apr. 22, 2024]