Title 40—Protection of Environment--Volume 1
PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES
§ 86.119-90   CVS calibration.
The CVS is calibrated using an accurate flowmeter and restrictor valve. Measurements of various parameters are made and related to flow through the unit. Procedures used by EPA for both PDP and CFV are outlined below. Other procedures yielding equivalent results may be used if approved in advance by the Administrator. After the calibration curve has been obtained, verification of the entire system can be performed by injecting a known mass of gas into the system and comparing the mass indicated by the system to the true mass injected. An indicated error does not necessarily mean that the calibration is wrong, since other factors can influence the accuracy of the system, e.g., analyzer calibration. A verification procedure is found in paragraph (c) of this section.
(a) PDP calibrations. (1) The following calibration procedure outlines the equipment, the test configuration, and the various parameters which must be measured to establish the flow rate of the CVS pump. All the parameters related to the pump are simultaneously measured with the parameters related to a flowmeter which is connected in series with the pump. The calculated flow rate ft 3 /min (at pump inlet absolute pressure and temperature) can then be plotted versus a correlation function which is the value on a specific combination of pump parameters. The linear equation which relates the pump flow and the correlation function is then determined. In the event that a CVS has a multiple speed drive, a calibration for each range used must be performed.
(2) This calibration procedure is based on the measurement of the absolute values of the pump and flowmeter parameters that relate the flow rate at each point. Three conditions must be maintained to assure the accuracy and integrity of the calibration curve. First, the pump pressures should be measured at taps on the pump rather than at the external piping on the pump inlet and outlet. Pressure taps that are mounted at the top center and bottom center of the pump drive headplate are exposed to the actual pump cavity pressures, and therefore reflect the absolute pressure differentials. Secondly, temperature stability must be maintained during the calibration. The laminar flowmeter is sensitive to inlet temperature oscillations which cause the data points to be scattered. Gradual changes (±2 °F (1.1 °C)) in temperature are acceptable as long as they occur over a period of several minutes. Finally, all connections between the flowmeter and the CVS pump must be absolutely void of any leakage.
(3) During an exhaust emission test the measurement of these same pump parameters enables the user to calculate the flow rate from the calibration equation.
(4) Connect a system as shown in Figure B90-8. Although particular types of equipment are shown, other configurations that yield equivalent results may be used if approved in advance by the Administrator. For the system indicated, the following data with given accuracy are required:
Calibration Data Measurements
(5) After the system has been connected as shown in Figure B90-8, set the variable restrictor in the wide open position and run the CVS pump for 20 minutes. Record the calibration data.
(6) Reset the restrictor valve to a more restricted condition in an increment of pump inlet depression (about 4 in. H 2 O (1.0 kPa) that will yield a minimum of six data points for the total calibration. Allow the system to stabilize for 3 minutes and repeat the data acquisition.
(7) Data analysis:
(i) The air flow rate, Q s , at each test point is calculated in standard cubic feet per minute from the flowmeter data using the manufacturer's prescribed method.
(ii) The air flow rate is then converted to pump flow, V o , in cubic feet per revolution at absolute pump inlet temperature and pressure:
(iii) The correlation function at each test point is then calculated from the calibration data:
(8) A CVS system that has multiple speeds should be calibrated on each speed used. The calibration curves generated for the ranges will be approximately parallel and the intercept values, D o , will increase as the pump flow range decreases.
(9) If the calibration has been performed carefully, the calculated values from the equation will be within ±0.50 percent of the measured value of V o . Values of M will vary from one pump to another, but values of D o for pumps of the same make, model, and range should agree within ±3 percent of each other. Particulate influx from use will cause the pump slip to decrease as reflected by lower values for M. Calibrations should be performed at pump start-up and after major maintenance to assure the stability of the pump slip rate. Analysis of mass injection data will also reflect pump slip stability.
(b) CFV calibration. (1) Calibration of the CFV is based upon the flow equation for a critical venturi. Gas flow is a function of inlet pressure and temperature:
(2) The manufacturer's recommended procedure shall be followed for calibrating electronic portions of the CFV.
(3) Measurements necessary for flow calibration are as follows:
Calibration Data Measurements
1 Requirement begins August 20, 2001.
(4) Set up equipment as shown in Figure B90-9 and check for leaks. Any leaks between the flow measuring device and the critical flow venturi will seriously affect the accuracy of the calibration.
(5) Set the variable flow restrictor to the open position, start the blower, and allow the system to stabilize. Record data from all instruments.
(6) Vary the flow restrictor and make at least 8 readings across the critical flow range of the venturi.
(7) Data analysis: The data recorded during the calibration are to be used in the following calculations:
(i) The air flow rate, Q s , at each test point is calculated in standard cubic feet per minute from the flow meter data using the manufacturer's prescribed method.
(ii) Calculate values of the calibration coefficient for each test point:
(iii) Plot K v as a function of venturi inlet pressure. For sonic flow K v will have a relatively constant value. As pressure decreases (vacuum increases), the venturi becomes unchoked and K v decreases. See Figure B90-10.
(iv) For a minimum of 8 points in the critical region calculate an average K v and the standard deviation.
(v) If the standard deviation exceeds 0.3 percent of the average K v take corrective action.
(8) Calculation of a parameter for monitoring sonic flow in the CFV during exhaust emissions tests:
(i) Option 1. (A) CFV pressure ratio. Based upon the calibration data selected to meet the criteria for paragraphs (d)(7) (iv) and (v) of this section, in which K v is constant, select the data values associated with the calibration point with the lowest absolute venturi inlet pressure. With this set of calibration data, calculated the following CFV pressure ratio limit, Pr ratio-lim :
(B) The venturi pressure ratio (Pr ratio-i ) during all emissions tests must be less than, or equal to, the calibration pressure ratio limit (Pr ratio-lim ) derived from the CFV calibration data, such that:
(ii) Option 2. Other methods: With prior Administrator approval, any other method may be used that assure that the venturi operates at sonic conditions during emissions tests, provided the method is based upon sound engineering principles.
(c) CVS System Verification. The following “gravimetric” technique can be used to verify that the CVS and analytical instruments can accurately measure a mass of gas that has been injected into the system. If the CVS and analytical system will be used only in the testing of petroleum-fueled engines, the system verification may be performed using either propane or carbon monoxide. If the CVS and analytical system will be used with methanol-fueled vehicles as well as petroleum-fueled vehicles, system verification performance check must include a methanol check in addition to either the propane or carbon monoxide check. (Verification can also be accomplished by constant flow metering using critical flow orifice devices.)
(1) Obtain a small cylinder that has been charged with pure propane or carbon monoxide gas (CAUTION—carbon monoxide is poisonous).
(2) Determine a reference cylinder weight to the nearest 0.01 grams.
(3) Operate the CVS in the normal manner and release a quantity of pure propane or carbon monoxide into the system during the sampling period (approximately 5 minutes).
(4) Following completion of step (3) in this paragraph (c) (if methanol injection is required), continue to operate the CVS in the normal manner and release a known quantity of pure methanol (in gaseous form) into the system during the sampling period (approximately five minutes). This step does not need to be performed with each verification, provided that it is performed at least twice annually.
(5) The calculations of § 86.144 are performed in the normal way, except in the case of propane. The density of propane (17.30 g/ft 3 /carbon atom (0.6109 kg/m 3 /carbon atom)) is used in place of the density of exhaust hydrocarbons. In the case of carbon monoxide, the density of 32.97 g/ft 3 (1.164 kg/m 3 ) is used. In the case of methanol, the density of 37.71 g/ft 3 (1.332 kg/m 3 ) is used.
(6) The gravimetric mass is subtracted from the CVS measured mass and then divided by the gravimetric mass to determine the percent accuracy of the system.
(7) The cause for any discrepancy greater than ±2 percent must be found and corrected. (For 1991-1995 calendar years, discrepancies greater than ±2 percent are allowed for the methanol test, provided that they do not exceed ±8 percent for 1991 testing or ±6 percent for 1992-1995 testing.)
§ 86.120-94   Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.
(a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters or flow instrumentation to determine flow through the particulate filters, methanol impingers and formaldehyde impingers. These instruments shall receive initial and periodic calibrations as follows:
(1)(i) Install a calibration device in series with the instrument. A critical flow orifice, a bellmouth nozzle, a laminar flow element or an NBS traceable flow calibration device is required as the standard device.
(ii) The flow system should be checked for leaks between the calibration and sampling meters, including any pumps that may be part of the system, using good engineering practice.
(2) Flow air through the calibration system at the sample flow rate used for particulate, methanol, and formaldehyde testing and at the backpressure which occurs during the test.
(3) When the temperature and pressure in the system have stabilized, measure the indicated gas volume over a time period of at least five minutes or until a gas volume of at least ±1 percent accuracy can be determined by the standard device. Record the stabilized air temperature and pressure upstream of the instrument and as required for the standard device.
(4) Calculate air flow at standard conditions as measured by both the standard device and the instrument(s). (Standard conditions are defined as 68 °F (20 °C) and 29.92 in Hg (101.3 kPa).)
(5) Repeat the procedures of paragraphs (a)(2) through (4) of this section using at least two flow rates which bracket the typical operating range.
(6) If the air flow at standard conditions measured by the instrument differs by ±1.0 percent of the maximum operating range or ±2.0 percent of the point (whichever is smaller), then a correction shall be made by either of the following two methods:
(i) Mechanically adjust the instrument so that it agrees with the calibration measurement at the specified flow rates using the criteria of paragraph (a)(6) of this section; or
(ii) Develop a continuous best fit calibration curve for the instrument (as a function of the calibration device flow measurement) from the calibration points to determine corrected flow. The points on the calibration curve relative to the calibration device measurements must be within ±1.0 percent of the maximum operating range of ±2.0 percent of the point (whichever is smaller).
(b) Other systems. A bell prover may be used to calibrate the instrument if the procedure outlined in ANSI B109.1-1973 is used. Prior approval by the Administrator is not required to use the bell prover.
§ 86.121-90   Hydrocarbon analyzer calibration.
The hydrocarbon analyzers shall receive the following initial and periodic calibration. The HFID used with petroleum-fueled diesel vehicles shall be operated at a temperature of 375 °F±10 °F (191 °±6 °C). The HFID used with methanol-fueled vehicles shall be operated at 235 °±15 °F (113±8 °C).
(a) Initial and periodic optimization of detector response. Prior to its introduction into service and at least annually thereafter, the FID and HFID hydrocarbon analyzers shall be adjusted for optimum hydrocarbon response. Alternate methods yielding equivalent results may be used, if approved in advance by the Administrator.
(1) Follow the manufacturer's instructions or good engineering practice for instrument startup and basic operating adjustment using the appropriate FID fuel and zero-grade air.
(2) Optimize on the most common operating range. Introduce into the analyzer a propane (methane as appropriate) in air mixture (methanol in air mixture for methanol-fueled vehicles when optional methanol calibrated HFID procedure is used during the 1994 model year) with a propane (or methane or methanol as appropriate) concentration equal to approximately 90 percent of the most common operating range.
(3) One of the following is required for FID or HFID optimization:
(i) For all FIDs and HFIDs, the procedures specified by the applicable FID or HFID manufacturer.
(ii) For Beckman 400 FIDs only, implementation of the recommendations outlined in Society of Automotive Engineers (SAE) paper No. 770141, “Optimization of Flame Ionization Detector for Determination of Hydrocarbons in Diluted Automobile Exhaust”; author, Glenn D. Reschke.
(iii) For HFIDs only, the following peaking procedure. (A) With the fuel and air flow rates set in the manufacturer's recommendations, determine the analyzer response from the difference between the span-gas response and the zero gas response. Incrementally adjust the fuel flow above and below the manufacturer's specification. Record the span and zero response at these fuel flows. A plot of the difference between the span and zero response versus the fuel flow will be similar to the one shown in Fig. B87-11. Adjust the fuel-flow rate to the highest setting that produces the maximum analyzer response.
(B) To determine the optimum air flow, use the fuel flow setting determined in paragraph (a)(3)(iii)(A) of this section and vary air flow.
(iv) Alternative procedures may be used if approved in advance by the Administrator.
(4) To determine the optimum air flow, use the FID fuel flow setting determined above and vary air flow.
(5) After the optimum flow rates have been determined, record them for future reference.
(b) Initial and periodic calibration. Prior to its introduction into service and monthly thereafter the FID or HFID hydrocarbon analyzers shall be calibrated on all normally used instrument ranges, and, if testing methanol vehicles under the procedure described in § 86.107-90(a)(2)(ii) or § 86.110-90(a)(4), the methanol response factor shall be determined (paragraph (c) of this section). Use the same flow rate as when analyzing sample.
(1) Adjust analyzer to optimize performance.
(2) Zero the hydrocarbon analyzer with zero-grade air.
(3) Calibrate on each normally used operating range with propane in air calibration gases (either methanol or methane in air as appropriate) having nominal concentrations of 15, 30, 45, 60, 75 and 90 percent of that range. For each range calibrated, if the deviation from a least squares best-fit straight line is two percent or less of the value at each data point, concentration values may be calculated by use of a single calibration factor for that range. If the deviation exceeds two percent at any point, the best-fit non-linear equation which represents the data to within two percent of each test point shall be used to determine concentration.
(c) FID response factor to methanol. When the FID analyzer is to be used for the analysis of hydrocarbon samples containing methanol, the methanol response factor of the analyzer shall be established. The methanol response factor shall be determined at several concentrations in the range of concentrations in the exhaust sample, using either bag samples or gas bottles meeting the requirements of § 86.114.
(1) The bag sample of methanol for analysis in the FID, if used, shall be prepared using the apparatus shown in Figure B90-11. A known volume of methanol is injected, using a microliter syringe, into the heated mixing zone (250 °F (121 °C)) of the apparatus. The methanol is vaporized and swept into the sample bag with a known volume of zero grade air measured by a gas flow meter meeting the performance requirements of § 86.120.
(2) The bag sample is analyzed using the FID.
(3) The FID response factor, r, is calculated as follows:
(i) r = FID response factor.
(ii) FIDppm = FID reading in ppmC.
(iii) SAMppm = methanol concentration in the sample bag, or gas bottle, in ppmC. SAMppm for sample bags
(iv) 0.02406 = Volume of one mole at 29.92 in. Hg and 68 °F, m 3 .
(v) Fuel injected = Volume of methanol injected, ml.
(vi) Fuel density = Density of methanol, 0.7914 g/ml.
(vii) Air volume = Volume of zero grade air, m 3 .
(viii) Mol. Wt. CH 3 OH = 32.04.
(d) FID response factor to methane. When the FID analyzer is to be used for the analysis of gasoline, diesel, methanol, ethanol, liquefied petroleum gas, and natural gas-fueled vehicle hydrocarbon samples, the methane response factor of the analyzer must be established. To determine the total hydrocarbon FID response to methane, known methane in air concentrations traceable to the National Institute of Standards and Technology (NIST) must be analyzed by the FID. Several methane concentrations must be analyzed by the FID in the range of concentrations in the exhaust sample. The total hydrocarbon FID response to methane is calculated as follows:
Where:
(1) r CH4 = FID response factor to methane.
(2) FIDppm = FID reading in ppmC.
(3) SAMppm = the known methane concentration in ppmC.
§ 86.122-78   Carbon monoxide analyzer calibration.
The NDIR carbon monoxide analyzer shall receive the following initial and periodic calibrations:
(a) Initial and periodic interference check. Prior to its introduction into service and annually thereafter the NDIR carbon monoxide analyzer shall be checked for response to water vapor and CO 2 :
(1) Follow the manufacturer's instructions for instrument startup and operation. Adjust the analyzer to optimize performance on the most sensitive range to be used.
(2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen.
(3) Bubble a mixture of 3 percent CO 2 in N 2 through water at room temperature and record analyzer response.
(4) An analyzer response of more than 1 percent of full scale for ranges above 300 ppm full scale or of more than 3 ppm on ranges below 300 ppm full scale will require corrective action. (Use of conditioning columns is one form of corrective action which may be taken.)
(b) Initial and periodic calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon monoxide analyzer shall be calibrated.
(1) Adjust the analyzer to optimize performance.
(2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen.
(3) Calibrate on each normally used operating range with carbon monoxide in N 2 calibration gases having nominal concentrations of 15, 30, 45, 60, 75, and 90 percent of that range. Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values may be calculated by use of a single calibration factor for that range. If the deviation exceeds 2 percent at any point, the best-fit non-linear equation which represents the data to within 2 percent of each test point shall be used to determine concentration.
§ 86.123-78   Oxides of nitrogen analyzer calibration.
The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic calibration.
(a) Prior to introduction into service and at least monthly thereafter the chemiluminescent oxides of nitrogen analyzer must be checked for NO 2 to NO converter efficiency. Figure B78-9 is a reference for paragraphs (a) (1) through (11) of this section.
(1) Follow the manufacturer's instructions for instrument startup and operation. Adjust the analyzer to optimize performance.
(2) Zero the oxides of nitrogen analyzer with zero-grade air or zero-grade nitrogen.
(3) Connect the outlet of the NO X generator to the sample inlet of the oxides of nitrogen analyzer which has been set to the most common operating range.
(4) Introduce into the NO X generator analyzer-system an NO in nitrogen (N 2 ) mixture with an NO concentration equal to approximately 80 percent of the most common operating range. The NO 2 content of the gas mixture shall be less than 5 percent of the NO concentration.
(5) With the oxides of nitrogen analyzer in the NO mode, record the concentration of NO indicated by the analyzer.
(6) Turn on the NO X generator O 2 (or air) supply and adjust the O 2 (or air) flow rate so that the NO indicated by the analyzer is about 10 percent less than indicated in step (5). Record the concentration of NO in this NO + O 2 mixture.
(7) Switch the NO X generator to the generation mode and adjust the generation rate so that the NO measured on the analyzer is 20 percent of that measured in step (5). There must be at least 10 percent unreacted NO at this point. Record the concentration of residual NO.
(8) Switch the oxides of nitrogen analyzer to the NO X mode and measure total NO X . Record this value.
(9) Switch off the NO X generation but maintain gas flow through the system. The oxides of nitrogen analyzer will indicate the NO X in the NO + O 2 mixture. Record this value.
(10) Turn off the NO X generator O 2 (or air) supply. The analyzer will now indicate the NO X in the original NO in N 2 mixture. This value should be no more than 5 percent above the value indicated in step (4).
(11) Calculate the efficiency of the NO X converted by substituting the concentrations obtained into the following equation:
(b) Initial and periodic calibration. Prior to its introduction into service and monthly thereafter the chemiluminescent oxides of nitrogen analyzer shall be calibrated on all normally used instrument ranges. Use the same flow rate as when analyzing samples. Proceed as follows:
(1) Adjust analyzer to optimize performance.
(2) Zero the oxides of nitrogen analyzer with zero-grade air or zero-grade nitrogen.
(3) Calibrate on each normally used operating range with NO in N2 calibration gases having nominal concentrations of 15, 30, 45, 60, 75, and 90 percent of that range. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values may be calculated by use of a single calibration factor for that range. If the deviation exceeds 2 percent at any point, the best-fit non-linear equation which represents the data to within 2 percent of each test point shall be used to determine concentration.
(c) When testing methanol-fueled vehicles, it may be necessary to clean the analyzer frequently to prevent interference with NO X measurements (see EPA/600/S3-88/040).
§ 86.124-78   Carbon dioxide analyzer calibration.
Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:
(a) Follow the manufacturer's instructions for instrument startup and operation. Adjust the analyzer to optimize performance.
(b) Zero the carbon dioxide analyzer with either zero-grade air or zero-grade nitrogen.
(c) Calibrate on each normally used operating range with carbon dioxide in N 2 calibration gases with nominal concentrations of 15, 30, 45, 60, 75, and 90 percent of that range. Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values may be calculated by use of a single calibration factor for that range. If the deviation exceeds 2 percent at any point, the best-fit non-linear equation which represents the data to within 2 percent of each test point shall be used to determine concentration.
§ 86.125-94   Methane analyzer calibration.
Prior to introduction into service and monthly thereafter, the methane analyzer shall be calibrated:
(a) Follow the manufacturer's instructions for instrument startup and operation. Adjust the analyzer to optimize performance.
(b) Zero the methane analyzer with zero-grade air.
(c) Calibrate on each normally used operating range with CH 4 in air with nominal concentrations of 15, 30, 45, 60, 75, and 90 percent of that range. Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values may be calculated by use of a single calibration factor for that range. If the deviation exceeds 2 percent at any point, the best-fit non-linear equation which represents the data to within 2 percent of each test point shall be used to determine concentration.
§ 86.126-90   Calibration of other equipment.
Other test equipment used for testing shall be calibrated as often as required by the manufacturer or as necessary according to good practice. Specific equipment requiring calibration are the gas chromatograph and flame ionization detector used in measuring methanol and the high pressure liquid chromatograph (HPLC) and ultraviolet detector for measuring formaldehyde.
§ 86.127-00   Test procedures; overview.
Applicability. The procedures described in this and subsequent sections are used to determine the conformity of vehicles with the standards set forth in subpart A or S of this part (as applicable) for light-duty vehicles and light-duty trucks. Except where noted, the procedures of paragraphs (a) through (b) of this section, § 86.127-96 (c) and (d), and the contents of §§ 86.135-94, 86.136-90, 86.137-96, 86.140-94, 86.142-90, and 86.144-94 are applicable for determining emission results for vehicle exhaust emission systems designed to comply with the FTP emission standards, or the FTP emission element required for determining compliance with composite SFTP standards. Paragraphs (f) and (g) of this section discuss the additional test elements of aggressive driving (US06) and air conditioning (SC03) that comprise the exhaust emission components of the SFTP. Section 86.127-96(e) discusses fuel spitback emissions and paragraphs (h) and (i) of this section are applicable to all vehicle emission test procedures. Section 86.127-00 includes text that specifies requirements that differ from § 86.127-96. Where a paragraph in § 86.127-96 is identical and applicable to § 86.127-00, this may be indicated by specifying the corresponding paragraph and the statement “[Reserved]. For guidance see § 86.127-96.”
(a) The overall test consists of prescribed sequences of fueling, parking, and operating test conditions. Vehicles are tested for any or all of the following emissions:
(1) Gaseous exhaust THC, CO, NO X . CO 2 (for petroleum-fueled and gaseous- fueled vehicles), plus CH 3 OH and HCHO for methanol-fueled vehicles, plus CH 4 (for vehicles subject to the NMHC and NMHCE standards).
(2) Particulates.
(3) Evaporative HC (for gasoline-fueled, methanol-fueled and gaseous-fueled vehicles) and CH 3 OH (for methanol-fueled vehicles). The evaporative testing portion of the procedure occurs after the exhaust emission test; however, exhaust emissions need not be sampled to complete a test for evaporative emissions.
(4) Fuel spitback (this test is not required for gaseous-fueled vehicles).
(b) The FTP Otto-cycle exhaust emission test is designed to determine gaseous THC, CO, CO 2 , CH 4 , NO X , and particulate mass emissions from gasoline-fueled, methanol-fueled and gaseous-fueled Otto-cycle vehicles as well as methanol and formaldehyde from methanol-fueled Otto-cycle vehicles, while simulating an average trip in an urban area of 11 miles (18 kilometers). The test consists of engine start-ups and vehicle operation on a chassis dynamometer through a specified driving schedule (see paragraph (a), EPA Urban Dynamometer Driving Schedule, of appendix I to this part). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler.
(c)-(e) [Reserved]. For guidance see § 86.127-96.
(f) The element of the SFTP for exhaust emissions related to aggressive driving (US06) is designed to determine gaseous THC, NMHC, CO, CO 2 , CH 4 , and NO X emissions from gasoline-fueled or diesel-fueled vehicles (see § 86.158-00 Supplemental test procedures; overview, and § 86.159-00 Exhaust emission test procedures for US06 emissions). The test cycle simulates urban driving speeds and accelerations that are not represented by the FTP Urban Dynamometer Driving Schedule simulated trips discussed in paragraph (b) of this section. The test consists of vehicle operation on a chassis dynamometer through a specified driving cycle (see paragraph (g), US06 Dynamometer Driving Schedule, of appendix I to this part). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler.
(g)(1) The element of the SFTP related to the increased exhaust emissions caused by air conditioning operation (SC03) is designed to determine gaseous THC, NMHC, CO, CO 2 , CH 4 , and NO X emissions from gasoline-fueled or diesel fueled vehicles related to air conditioning use (see § 86.158-00 Supplemental federal test procedures; overview and § 86.160-00 Exhaust emission test procedure for SC03 emissions). The test cycle simulates urban driving behavior with the air conditioner operating. The test consists of engine startups and vehicle operation on a chassis dynamometer through specified driving cycles (see paragraph (h), SC03 Dynamometer Driving Schedule, of appendix I to this part). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler. The testing sequence includes an approved preconditioning cycle, a 10 minute soak with the engine turned off, and the SC03 cycle with measured exhaust emissions.
(2) The SC03 air conditioning test is conducted with the air conditioner operating at specified settings and the ambient test conditions of:
(i) Air temperature of 95 °F;
(ii) 100 grains of water/pound of dry air (approximately 40 percent relative humidity);
(iii) Simulated solar heat intensity of 850 W/m 2 (see § 86.161-00(d)); and
(iv) air flow directed at the vehicle that will provide representative air conditioner system condenser cooling at all vehicle speeds (see § 86.161-00(e)).
(3) Manufacturers have the option of simulating air conditioning operation during testing at other ambient test conditions provided they can demonstrate that the vehicle tail pipe exhaust emissions are representative of the emissions that would result from the SC03 cycle test procedure and the ambient conditions of paragraph (g)(2) of this section. The Administrator has approved two optional air conditioning test simulation procedures AC1 and AC2 (see § 86.162-00) for only the model years of 2000 through 2002. If a manufacturer desires to conduct simulation SC03 testing for model year 2003 and beyond, the simulation test procedure must be approved in advance by the Administrator (see §§ 86.162-00 and 86.163-00).
(h) Except in cases of component malfunction or failure, all emission control systems installed on or incorporated in a new motor vehicle shall be functioning during all procedures in this subpart. Maintenance to correct component malfunction or failure shall be authorized in accordance with § 86.098-25 or § 86.1834-01 as applicable.
(i) Background concentrations are measured for all species for which emissions measurements are made. For exhaust testing, this requires sampling and analysis of the dilution air. For evaporative testing, this requires measuring initial concentrations. (When testing methanol-fueled vehicles, manufacturers may choose not to measure background concentrations of methanol and/or formaldehyde, and then assume that the concentrations are zero during calculations.)
§ 86.127-12   Test procedures; overview.
Applicability. The procedures described in this subpart are used to determine the conformity of vehicles with the standards set forth in subpart A or S of this part (as applicable) for light-duty vehicles, light-duty trucks, and medium-duty passenger vehicles. Except where noted, the procedures of paragraphs (a) through (d) of this section, and the contents of §§ 86.135-00, 86.136-90, 86.137-96, 86.140-94, 86.142-90, and 86.144-94 are applicable for determining emission results for vehicle exhaust emission systems designed to comply with the FTP emission standards, or the FTP emission element required for determining compliance with composite SFTP standards. Paragraph (e) of this section discusses fuel spitback emissions. Paragraphs (f) and (g) of this section discuss the additional test elements of aggressive driving (US06) and air conditioning (SC03) that comprise the exhaust emission components of the SFTP. Paragraphs (h) and (i) of this section are applicable to all vehicle emission test procedures.
(a) The overall test consists of prescribed sequences of fueling, parking, and operating test conditions. Vehicles are tested for any or all of the following emissions, depending upon the specific test requirements and the vehicle fuel type:
(1) Gaseous exhaust THC, NMHC, NMOG, CO, NO X , CO 2 , N 2 O, CH 4 , CH 3 OH, C 2 H 5 OH, C 2 H 4 O, and HCHO.
(2) Particulates.
(3) Evaporative HC (for gasoline-fueled, methanol-fueled and gaseous-fueled vehicles) and CH 3 OH (for methanol-fueled vehicles). The evaporative testing portion of the procedure occurs after the exhaust emission test; however, exhaust emissions need not be sampled to complete a test for evaporative emissions.
(4) Fuel spitback (this test is not required for gaseous-fueled vehicles).
(b) The FTP Otto-cycle exhaust emission test is designed to determine gaseous THC, NMHC, NMOG, CO, CO 2 , CH 4 , NO X , N 2 O, and particulate mass emissions from gasoline-fueled, methanol-fueled and gaseous-fueled Otto-cycle vehicles as well as methanol and formaldehyde from methanol-fueled Otto-cycle vehicles, as well as methanol, ethanol, acetaldehyde, and formaldehyde from ethanol-fueled vehicles, while simulating an average trip in an urban area of approximately 11 miles (approximately 18 kilometers). The test consists of engine start-ups and vehicle operation on a chassis dynamometer through a specified driving schedule (see paragraph (a) of appendix I to this part for the Urban Dynamometer Driving Schedule). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler.
(c) The diesel-cycle exhaust emission test is designed to determine particulate and gaseous mass emissions during the test described in paragraph (b) of this section. For petroleum-fueled diesel-cycle vehicles, diluted exhaust is continuously analyzed for THC using a heated sample line and analyzer; the other gaseous emissions (CH 4 , CO, CO 2 , N 2 O, and NO X ) are collected continuously for analysis as in paragraph (b) of this section. For methanol- and ethanol-fueled vehicles, THC, methanol, formaldehyde, CO, CO 2 , CH 4 , N 2 O, and NO X are collected continuously for analysis as in paragraph (b) of this section. Additionally, for ethanol-fueled vehicles, ethanol and acetaldehyde are collected continuously for analysis as in paragraph (b) of this section. THC, methanol, ethanol, acetaldehyde, and formaldehyde are collected using heated sample lines, and a heated FID is used for THC analyses. Simultaneous with the gaseous exhaust collection and analysis, particulates from a proportional part of the diluted exhaust are collected continuously on a filter. The mass of particulate is determined by the procedure described in § 86.139. This testing requires a dilution tunnel as well as the constant volume sampler.
(d) The evaporative emission test (gasoline-fueled vehicles, methanol-fueled and gaseous-fueled vehicles) is designed to determine hydrocarbon and methanol evaporative emissions as a consequence of diurnal temperature fluctuation, urban driving and hot soaks following drives. It is associated with a series of events that a vehicle may experience and that may result in hydrocarbon and/or methanol vapor losses. The test procedure is designed to measure:
(1) Diurnal emissions resulting from daily temperature changes (as well as relatively constant resting losses), measured by the enclosure technique (see § 86.133-96);
(2) Running losses resulting from a simulated trip performed on a chassis dynamometer, measured by the enclosure or point-source technique (see § 86.134-96; this test is not required for gaseous-fueled vehicles); and
(3) Hot soak emissions, which result when the vehicle is parked and the hot engine is turned off, measured by the enclosure technique (see § 86.138-96).
(e) Fuel spitback emissions occur when a vehicle's fuel fill neck cannot accommodate dispensing rates. The vehicle test for spitback consists of a short drive followed immediately by a complete refueling event. This test is not required for gaseous-fueled vehicles.
(f) The element of the SFTP for exhaust emissions related to aggressive driving (US06) is designed to determine gaseous THC, NMHC, CO, CO 2 , CH 4 , and NO X emissions from gasoline-fueled or diesel-fueled vehicles (see § 86.158-08 Supplemental test procedures; overview, and § 86.159-08 Exhaust emission test procedures for US06 emissions). The test cycle simulates urban driving speeds and accelerations that are not represented by the FTP Urban Dynamometer Driving Schedule simulated trips discussed in paragraph (b) of this section. The test consists of vehicle operation on a chassis dynamometer through a specified driving cycle (see paragraph (g), US06 Dynamometer Driving Schedule, of appendix I to this part). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler.
(g)(1) The element of the SFTP related to the increased exhaust emissions caused by air conditioning operation (SC03) is designed to determine gaseous THC, NMHC, CO, CO 2 , CH 4 , and NO X emissions from gasoline-fueled or diesel fueled vehicles related to air conditioning use (see § 86.158-08 Supplemental Federal test procedures; overview and § 86.160-00 Exhaust emission test procedure for SC03 emissions). The test cycle simulates urban driving behavior with the air conditioner operating. The test consists of engine startups and vehicle operation on a chassis dynamometer through specified driving cycles (see paragraph (h), SC03 Dynamometer Driving Schedule, of appendix I to this part). A proportional part of the diluted exhaust is collected continuously for subsequent analysis, using a constant volume (variable dilution) sampler or critical flow venturi sampler. The testing sequence includes an approved preconditioning cycle, a 10 minute soak with the engine turned off, and the SC03 cycle with measured exhaust emissions.
(2) The SC03 air conditioning test is conducted with the air conditioner operating at specified settings and the ambient test conditions of:
(i) Air temperature of 95 °F;
(ii) 100 grains of water/pound of dry air (approximately 40 percent relative humidity);
(iii) Simulated solar heat intensity of 850 W/m 2 (see § 86.161-00(d)); and
(iv) Air flow directed at the vehicle that will provide representative air conditioner system condenser cooling at all vehicle speeds (see § 86.161-00(e)).
(3) Manufacturers have the option of simulating air conditioning operation during testing at other ambient test conditions provided they can demonstrate that the vehicle tail pipe exhaust emissions are representative of the emissions that would result from the SC03 cycle test procedure and the ambient conditions of paragraph (g)(2) of this section. The simulation test procedure must be approved in advance by the Administrator (see §§ 86.162-03 and 86.163-00).
(h) Except in cases of component malfunction or failure, all emission control systems installed on or incorporated in a new motor vehicle shall be functioning during all procedures in this subpart. Maintenance to correct component malfunction or failure shall be authorized in accordance with § 86.007-25 or § 86.1834-01 as applicable.
(i) Background concentrations are measured for all species for which emissions measurements are made. For exhaust testing, this requires sampling and analysis of the dilution air. For evaporative testing, this requires measuring initial concentrations. (When testing methanol-fueled vehicles, manufacturers may choose not to measure background concentrations of methanol and/or formaldehyde, and then assume that the concentrations are zero during calculations.)
§ 86.128-79   Transmissions.
(a) All test conditions, except as noted, shall be run according to the manufacturer's recommendations to the ultimate purchaser, Provided, That: Such recommendations are representative of what may reasonably be expected to be followed by the ultimate purchaser under in-use conditions.
(b) Vehicles equipped with free wheeling or overdrive, except as noted, shall be tested with these features operated according to the manufacturer's recommendations to the ultimate purchaser.
(c) Idle modes less than one minute in length shall be run with automatic transmissions in “Drive” and the wheels braked; manual transmissions shall be in gear with the clutch disengaged, except for the first idle mode (see §§ 86.134, 86.136, and 86.137). The first idle mode and idle modes longer than one minute in length may be run with automatic transmissions in “Neutral;” manual transmissions may be in “Neutral” with the clutch engaged (clutch may be disengaged for engine start-up). If an automatic transmission is in “Neutral” during an idle mode, it shall be placed in “Drive” with the wheels braked at least 5 seconds before the end of the idle mode. If a manual transmission is in “Neutral” during an idle mode, it shall be placed in gear with the clutch disengaged at least 5 seconds before the end of the idle mode.
(d) The vehicle shall be driven with appropriate accelerator pedal movement necessary to achieve the speed versus time relationship prescribed by the driving schedule. Both smoothing of speed variations and excessive accelerator pedal perturbations are to be avoided.
(e) Accelerations shall be driven smoothly following representative shift speeds and procedures. For manual transmissions, the operator shall release the accelerator pedal during each shift and accomplish the shift with minimum time. If the vehicle cannot accelerate at the specified rate, the vehicle shall be operated at maximum available power until the vehicle speed reaches the value prescribed for that time in the driving schedule.
(f) The deceleration modes shall be run in gear using brakes or accelerator pedal as necessary to maintain the desired speed. Manual transmission vehicles shall have the clutch engaged and shall not change gears from the previous mode. For those modes which decelerate to zero, manual transmission clutches shall be depressed when the speed drops below 15 mph (24.1 km/h), when engine roughness is evident, or when engine stalling is imminent.
(g)(1) In the case of test vehicles equipped with manual transmissions, the transmission shall be shifted in accordance with procedures which are representative of shift patterns that may reasonably be expected to be followed by vehicles in use, in terms of such variables as vehicle speed or percent rated engine speed. At the Administrator's discretion, a test vehicle may also be shifted according to the shift procedures recommended by the manufacturer to the ultimate purchaser, if such procedures differ from those which are reasonably expected to be followed by vehicles in use.
(2) A manufacturer may recommend to the ultimate purchaser shift procedures other than those used in testing by the EPA, Provided that: All shift procedures (including multiple shift speeds) which the manufacturer proposes to supply to the ultimate purchaser are provided to the Administrator as part of the manufacturer's application for certification, or as an amendment to such application, under § 86.079-32, § 86.079-33, § 86.082-34, or § 86.1844-01 as applicable.
(h) Downshifting is allowed at the beginning of or during a power mode in accordance with the shift procedure determined in paragraph (g)(1) of this section.
§ 86.129-00   Road load power, test weight, and inertia weight class determination.
Applicability. Section 86.129-94 (a) applies to all vehicle testing. Section 86.129-80 (b) and (c) are applicable to vehicles from engine families which are not required to meet SFTP requirements, although a manufacturer may elect to use the requirements in paragraphs (e) and (f) of this section instead of § 86.129-80 (b) and (c) on any vehicle. Section 86.129-94(d) which discusses fuel temperature profile, is applicable to evaporative emission running loss testing. Paragraphs (e) and (f) of this section are applicable to vehicles from engine families required to comply with SFTP requirements. Section 86.129-00 includes text that specifies requirements that differ from § 86.129-80 or § 86.129-94. Where a paragraph in § 86.129-80 or § 86.129-94 is identical and applicable to § 86.129-00, this may be indicated by specifying the corresponding paragraph and the statement “[Reserved]. For guidance see § 86.129-80.” or “[Reserved]. For guidance see § 86.129-94.”
(a) [Reserved]. For guidance see § 86.129-94.
(b)-(c) [Reserved]. For guidance see § 86.129-80.
(d) [Reserved]. For guidance see § 86.129-94.
(e)(1) For each test vehicle from an engine family required to comply with SFTP requirements, the manufacturer shall supply representative road load forces for the vehicle at speeds between 15 km/hr (9.3 mph) and 115 km/hr (71.5 mph). The road load force shall represent vehicle operation on a smooth level road, during calm winds, with no precipitation, at an ambient temperature of 20 °C (68 °F), and atmospheric pressure of 98.21 kPa. Road load force for low speed may be extrapolated. Manufacturers may, at their option, use road load forces meeting the objectives of paragraph (f) of this section for any vehicle.
(2) The dynamometer's power absorption shall be set for each vehicle's emission test sequence such that the force imposed during dynamometer operation matches actual road load force at all speeds.
(3) The 10 percent adjustment in road load power for air conditioning discussed in § 86.129-80(b)(3), is not applicable when road load forces are determined for dynamometer testing using paragraphs (e)(1) and (e)(2) of this section.
(f)(1) Required test dynamometer inertia weight class selections for the test elements of FTP, US06, and SC03 are determined by the test vehicles test weight basis and corresponding equivalent weight as listed in the tabular information of § 86.129-94(a). With the exception of the fuel economy test weight information in footnote 4 to the table in § 86.129-94(a), none of the other footnotes to the tabular listing apply to emission tests utilizing an approved single roll dynamometer or equivalent dynamometer configuration. All light-duty vehicles and light light-duty trucks are to be tested at the inertia weight class corresponding to their equivalent test weight.
(i) For light-duty vehicles and light light-duty trucks, test weight basis is loaded vehicle weight, which is the vehicle weight plus 300 pounds.
(ii) For heavy light-duty trucks, the definition of test weight basis varies depending on the SFTP test element being tested.
(A) For the aggressive driving cycle (US06), the test weight basis is the vehicle curb weight plus 300 pounds.
(B) For the FTP and the air conditioning (SC03) element of the SFTP, the test weight is the average of the curb weight plus GVWR.
(C) Regardless of other requirements in this section relating to the testing of HLDTs, for Tier 2 and Tier 3 HLDTs, the test weight basis for FTP and SFTP testing (both US06 and SC03), if applicable, is the vehicle curb weight plus 300 pounds. For MDPVs certified to standards in bin 11 in Tables S04-1 and 2 in § 86.1811-04, the test weight basis must be adjusted loaded vehicle weight (ALVW) as defined in this part.
(2) Dynamic inertia load adjustments may be made to the test inertia weight during specific US06 acceleration events when wide open throttle operation is equal to or greater than eight (8) seconds (see § 86.108-00). The dynamic inertia weight adjustment procedure must be approved in advance of conducting official US06 testing. The Administrator will perform confirmatory US06 testing using the same dynamometer inertia adjustment procedures as the manufacturer if:
(i) The manufacturer submits a request to the Administrator; and
(ii) The manufacturer provides the dynamometer hardware and/or software necessary for these adjustments to the Administrator.
§ 86.129-80   Road load power, test weight, and inertia weight class determination.
(a) [Reserved]
(b) Power absorption unit adjustment—light-duty trucks. (1) The power absorption unit shall be adjusted to reproduce road load power at 50 mph true speed. The indicated road load power setting shall take into account the dynamometer friction. The relationship between road load (absorbed) power and indicated road load power for a particular dynamometer shall be determined by the procedure outlined in § 86.118 or other suitable means.
(2) The road load power listed in the table above shall be used or the vehicle manufacturer may determine the road load power by an alternate procedure requested by the manufacturer and approved in advance by the Administrator.
(3) Where it is expected that more than 33 percent of a car line within an engine-system combination will be equipped with air conditioning per § 86.080-24(g)(2), the road load power listed above or as determined in paragraph (b)(2) of this section shall be increased by 10 percent, up to a maximum increase of 1.4 horsepower, for testing all test vehicies representing that car line within that engine-system combination if those vehicles are intended to be offered with air conditioning in production. The above increase for air conditioning shall be added prior to rounding off as instructed by notes 2 and 3 of the table.
(c) Power absorption unit adjustment—light-duty vehicles. (1) The power absorption unit shall be adjusted to reproduce road load power at 50 mph true speed. The dynamometer power absorption shall take into account the dynamometer friction, as discussed in § 86.118.
(2) The dynamometer road load setting is determined from the equivalent test weight, the reference frontal area, the body shape, the vehicle protuberances, and the tire type by the following equations.
(i) For light-duty vehicles to be tested on a twin roll dynamometer.
A vehicle is considered to have a fastback shape if the rearward projection of that portion of the rear surface ( A b ) which slopes at an angle of less than 20 degrees from the horizontal is at least 25 percent as large as the vehicle reference frontal area. In addition, this surface must be smooth, continuous, and free from any local transitions greater than four degrees. An example of a fastback shape is presented in Figure 1.
Table I—Protuberance Power, P. Versus Total Protuberance Frontal Area, A p
The protuberance frontal area, A p , is defined in a manner analogous to the definition of the vehicle reference frontal area, i.e., the total area of the orthogonal projections of the vehicle mirrors, hood ornaments, roof racks, and other protuberance onto a plane(s) perpendicular to both the longitudinal plane of the vehicle and the surface upon which the vehicle is positioned. A protuberance is defined as any fixture attached to the vehicle protruding more than 1 inch from the vehicle surface and having a projected area greater than 0.01 ft 2 with the area calculated by a method approved in advance by the Administrator. Included in the total protuberance frontal area shall be all fixtures which occur as standard equipment. The area of any optional equipment shall also be included if it is expected that more than 33 percent of the car line sold will be equipped with this option.
(ii) The dynamometer power absorber setting for light-duty vehicles shall be rounded to the nearest 0.1 horsepower.
(iii) For light-duty vehicles to be tested on a single, large roll dynamometer.
(3) The road load power calculated above shall be used or the vehicle manufacturer may determine the road load power by an alternate procedure requested by the manufacturer and approved in advance by the Administrator.
(4) Where it is expected that more than 33 percent of a car line within an engine-system combination will be equipped with air conditioning, per § 86.080-24(g)(2), the road load power as determined in paragraph (c) (2) or (3) of this section shall be increased by 10 percent up to a maximum increment of 1.4 horsepower, for testing all test vehicles of that car line within that engine-system combination if those vehicles are intended to be offered with air conditioning in production. This power increment shall be added to the indicated dynamometer power absorption setting prior to rounding off this value.
§ 86.129-94   Road load power, test weight, inertia weight class determination, and fuel temperature profile.
Section 86.129-94 includes text that specifies requirements that differ from § 86.129-80. Where a paragraph in § 86.129-80 is identical and applicable to § 86.129-94, this may be indicated by specifying the corresponding paragraph and the statement “[Reserved]. For guidance see § 86.129-80.” Where a corresponding paragraph of § 86.129-80 is not applicable, this is indicated by the statement “[Reserved].”
(a) Flywheels, electrical, or other means of simulating test weight as shown in the following table shall be used. If the equivalent test weight specified is not available on the dynamometer being used, the next higher equivalent test weight (not to exceed 250 pounds) available shall be used:
1 For all light-duty trucks except vans, and for heavy-duty vehicles optionally certified as light-duty trucks, and for complete heavy-duty vehicles, the road load power (horsepower) at 50 mi/h shall be 0.58 times B (defined in footnote 3 of this table) rounded to the nearest 1/2 horsepower.
2 For vans, the road load power at 50 mi/h (horsepower) shall be 0.50 times B (defined in footnote 3 of this table) rounded to the nearest 1/2 horsepower.
3 B is the basic vehicle frontal area (square foot) plus the additional frontal area (square foot) of mirrors and optional equipment exceeding 0.1 ft 2 which are anticipated to be sold on more than 33 percent of the car line. Frontal area measurements shall be computed to the nearest 10th of a square foot using a method approved in advance by the Administrator.
4 For model year 1994 and later heavy light-duty trucks not subject to the Tier 0 standards of § 86.094-9, test weight basis is as follows: for emissions tests, the basis shall be adjusted loaded vehicle weight, as defined in § 86.094-2; and for fuel economy tests, the basis shall be loaded vehicle weight, as defined in § 86.082-2, or, at the manufacturer's option, adjusted loaded vehicle weight as defined in § 86.094-2. For all other vehicles, test weight basis shall be loaded vehicle weight, as defined in § 86.082-2.
5 Light-duty vehicles over 5,750 lb. loaded vehicle weight shall be tested at a 5,500 lb. equivalent test weight.
(b)-(c) [Reserved]. For guidance see § 86.129-80.
(d) Fuel temperature profile —(1) General requirements. (i) To be tested for running losses, as specified in § 86.134, a vehicle must have a fuel temperature profile. The following procedure is used to generate the fuel temperature profile, which serves as a target for controlling fuel temperatures during the running loss test. This profile represents the fuel temperature change that occurs during on-road driving. If a vehicle has more than one fuel tank, a profile shall be established for each tank. Manufacturers may also simultaneously generate a profile for vapor temperatures.
(ii) If a manufacturer uses a vehicle model to develop a profile to represent multiple models, the vehicle model selected must have the greatest expected fuel temperature increase during driving of all those models it represents. Also, manufacturers must select test vehicles with any available vehicle options that increase fuel temperatures during driving (for example, any feature that limits underbody airflow).
(iii) Manufacturers may conduct testing to develop fuel temperature profiles in a laboratory setting, subject to approval by the Administrator. The laboratory facility should simulate outdoor testing to reproduce fuel and vapor temperature behavior over the specified driving schedule. The design of the laboratory facility should include consideration of any parameters that may affect fuel temperatures, such as solar loading, pavement heat, and relative wind velocities around and underneath the test vehicle. Indoor testing to develop the fuel temperature profiles must be conducted with little or no vehicle-specific adjustment of laboratory parameters. Manufacturers would need to maintain an ongoing demonstration of correlation between laboratory and outdoor measurement of fuel temperatures. Specifically, fuel temperatures and pressures from indoor driving should be at least as high as measured when driving outdoors according to the procedures described in this section.
(iv) Small-volume manufacturers, as defined in § 86.094-14(b)(1), may use an alternate method for generating fuel temperature profiles, subject to the approval of the Administrator.
(v) The Administrator may conduct testing to establish any vehicle's temperature profiles or to verify compliance with fuel tank pressure requirements.
(2) Vehicle instrumentation. (i) The vehicle must be equipped with temperature sensors and pressure transducers, as described in § 86.107-96 (e) and (f), and a driver's aid, which shall be configured to provide the test driver with the desired vehicle speed vs. time trace and the actual vehicle speed.
(ii) A computer, data logger, or strip chart data recorder shall record the following parameters at a minimum during the test run:
(A) Desired speed;
(B) Actual speed;
(C) Instantaneous average liquid fuel temperature (T liq ); and
(D) Vapor space pressure (the Administrator may omit measurement of fuel tank pressure).
(iii) The data recording system described in paragraph (d)(2)(ii) of this section shall be capable of resolving time to ±1 s, capable of resolving temperature to ±2 °F, capable of resolving pressure to ±1.0 inch of water, and capable of resolving speed to ±1 mph. The temperature and pressure signals shall be recorded at intervals of up to 1 minute; speed signals shall be recorded at intervals of up to 1 second.
(3) Ambient conditions. The procedure shall be run under the following ambient conditions. Conditions should be representative of sunny summer days.
(i) Starting ambient temperature (T amb, o ) shall be at least 95 °F, steady or increasing (no more than 2 °F drop) during the procedure. Ambient temperature shall be measured and recorded in regular intervals of at least once every 5 minutes. Measure ambient temperature with the following requirements (based on Federal Standard for Siting Meteorological Sensors at Airports, FCM-S4-1987). The sensors shall be mounted 5 ±1 feet (1.5 ±0.3 meters) above ground level. The sensors shall be protected from radiation from the sun, sky, earth, and any other surrounding objects, but at the same time be adequately ventilated. The sensors shall be installed in such a position as to ensure that measurements are representative of the free air circulation in the locality and not influenced by artificial conditions such as large buildings, cooling towers, and expanses of concrete and tarmac. Keep any grass and vegetation within 100 feet (30 meters) of the sensor clipped to a height of about 10 inches (25 centimeters) or less.
(ii) Wind conditions shall be calm to light with maximum wind speed of 15 mph. In the case of temporary gusting, wind speeds between 15 and 25 mph may occur for up to 5 percent of the total driving time without invalidating the data collection. Wind speed shall be measured and recorded in regular intervals of at least once per minute. Measure wind speed with the following requirements (based on Federal Standard for Siting Meteorological Sensors at Airports, FCM-S4-1987). The site should be relatively level, but small gradual slopes are acceptable. The sensor shall be mounted 30 to 33 feet (9 to 10 meters) above the average ground height within a radius of 500 feet (150 meters). The sensor height shall not exceed 33 feet, except as necessary to be at least 15 feet (5 meters) above the height of any obstruction (e.g. vegetation, buildings, etc.) within a 500 foot (150 meter) radius. An object is considered to be an obstruction if the included lateral angle from the sensor to the ends of the object is 10 degrees or more.
(iii) Road surface temperature shall be at least 125 °F throughout the driving period. Pavement temperature shall be measured and recorded in regular intervals of at least once per minute. The track temperature may be measured with an embedded sensor, a portable temperature probe, or an infrared pyrometer that can provide an accuracy of ±2 °F. Temperatures must be measured on a surface representative of the surface where the vehicle is driven.
(iv) Conditions shall be sunny or mostly sunny with a maximum cloud cover of 25 percent.
(v) Reported cloud cover, wind speed, and ambient temperature should be consistent with that reported by the nearest weather station; the Administrator may request justification of any discrepancy.
(4) Profile determination procedure. (i) Drain the fuel tank(s) and fill with test fuel to the “tank fuel volume” defined in § 86.082-2. The test fuel should meet the specifications of § 86.113, except that fuel with a lower volatility may be used, subject to Administrator approval. Manufacturers using a lower volatility fuel must generate a vapor temperature profile for demonstrating compliance with the limit on fuel tank pressure during the running loss test (see § 86.134-96).
(ii) The vehicle shall be moved to the location where the data is to be collected. It may be driven a maximum distance of 5 miles and may also be transported by other means. The vehicle shall be stabilized by one of the following methods:
(A) The vehicle shall be parked for a minimum of 12 hours in an open area on a surface that is representative of the test road, without any artificial heating or cooling of the fuel. The orientation of the front of the vehicle during parking (e.g., N, SW, etc.) shall be documented.
(B) The vehicle may be soaked in a temperature-controlled environment to stabilize fuel temperatures. Before starting the drive, the vehicle shall be stabilized with fuel temperatures 95 ±3 °F for at least one hour. The fuel temperature may not exceed 98 °F at any time before the beginning of the driving schedule, during which only whole-vehicle heating and cooling may be used to control fuel temperatures. If a manufacturer uses the provisions of paragraph (d)(7)(v) of this section to establish a lower initial fuel temperature for the running loss test, the fuel in the test vehicle may not be stabilized at a temperature higher than the newly established initial fuel temperature.
(iii) Once the ambient conditions specified in paragraph (d)(3) of this section are met and the vehicle has been stabilized according to paragraph (d)(4)(ii) of this section, the vehicle's engine may be started. The vehicle's air conditioning system (if so equipped) shall be set to the “normal” air conditioning mode and adjusted to the minimum discharge air temperature and high fan speed. Vehicles equipped with automatic temperature controlled air conditioning systems shall be set to operate in “automatic” temperature and fan modes with the system set at 72 °F.
(iv) The vehicle may be operated at minimum throttle for a period up to 60 seconds prior to the start of the driving schedule, as necessary to move from the parking location onto the road surface. The driver's aid shall be started and the vehicle operated over the driving cycle specified in § 86.134-96(b) with the transmission operated in the same manner as specified in § 86.128-79. The data recording system shall provide a record of the required parameters over the entire period of driving.
(5) Records required. In addition to the vehicle data recording, the following parameters shall be documented for the determination of the fuel temperature profile:
(i) Date and time of vehicle fueling;
(ii) Odometer reading at vehicle fueling;
(iii) Date and time vehicle was parked, parking location and orientation;
(iv) Odometer reading at parking;
(v) Date and time engine was started;
(vi) Time of initiation of first UDDS;
(vii) Time of completion of the driving cycle;
(viii) Ambient temperatures throughout the period of driving (T amb );
(ix) Wind speed throughout the period of driving;
(x) Track surface temperatures throughout the period of driving cycle (T sur );
(xi) Percent cloud cover during the period of driving; and
(xii) Ambient temperature, wind speed, and percent cloud cover reported by the nearest weather station for the time corresponding most closely to the period of driving.
(6) Fuel tank pressure. Tank pressure shall not exceed 10 inches of water at any time during the temperature profile determination unless a pressurized system is used and the manufacturer demonstrates that vapor would not be vented to the atmosphere upon fuel cap removal.
(7) Calculation of temperature profiles. (i) The traces from the driving schedule shall be verified to meet the speed tolerance requirements of § 86.115. The following conditions shall be verified:
(A) T amb, i ≥T amb, o −2 °F.
( 1 )i = instantaneous measurement throughout the drive; and
( 2 )o = initial measurement at the start of the specified driving schedule.
(B) T amb, o ≥95 °F.
(C) T sur, i −T amb, i ≥30 °F.
(D) W max ≤15 mph.
(ii) Failure to comply with any of these requirements shall result in invalidation of the data and require that the procedure be repeated, beginning with the fuel drain at paragraph (d)(4)(i) of this section.
(iii) If all these requirements are met, the following calculations shall be performed to determine a profile for liquid fuel temperatures and, if applicable, for vapor temperatures:
(A) Ti, profile = the series of temperatures that comprise the relative temperature profile.
(B) T i = the series of observed liquid fuel or vapor temperatures during the drive.
(C) T o = the liquid fuel or vapor temperature observed at the start of the specified driving schedule.
(iv) The relative temperature profile consists of the set of temperatures at each 1-minute interval. If temperatures are sampled more frequently than once per minute, the temperature data points may represent a rolling average of temperatures sampled for up to one-minute intervals. If multiple valid test runs are conducted for any model, then all the collected data shall be used to calculate a composite profile, based on the average temperatures at each point. The absolute temperature profile is determined by adding 95 °F (35 °C) to each point of the relative profile. Other methodologies for developing corrected liquid fuel and vapor space temperature profiles may be used if demonstrated to yield equivalent results and approved in advance by the Administrator.
(v) Manufacturers may use a lower initial fuel temperature for the running loss test, if approved in advance by the Administrator. To demonstrate the need for such an adjustment, manufacturers would be expected to determine the maximum fuel temperature experienced by a vehicle during an extended park or after driving one UDDS cycle when exposed to the ambient conditions described in paragraph (d)(3) of this section. To use this provision, manufacturers would have to show maximum fuel temperatures no greater than 92 °F.
§ 86.130-96   Test sequence; general requirements.
Paragraphs (a) through (d) of this section are applicable to vehicles tested for the FTP test. Paragraph (e) of this section is applicable to vehicles tested for the SFTP supplemental tests of air conditioning (SC03) and aggressive driving (US06). Paragraph (f) of this section is applicable to all emission testing.
(a)(1) Gasoline- and methanol-fueled vehicles . The test sequence shown in Figure 1 of 40 CFR 1066.801 shows the steps encountered as the test vehicle undergoes the procedures subsequently described to determine conformity with the standards set forth. The full three- diurnal sequence depicted in Figure 1 of 40 CFR 1066.801 tests vehicles for all sources of evaporative emissions. The supplemental two-diurnal test sequence is designed to verify that vehicles sufficiently purge their evaporative canisters during the exhaust emission test. Sections 86.132-96, 86.133-96, and 86.138-96 describe the separate specifications of the supplemental two-diurnal test sequence.
(2) Gaseous-fueled vehicles . The test sequence shown in Figure 1 of 40 CFR 1066.801 shows the steps encountered as the test vehicle undergoes the procedures subsequently described to determine conformity with the standards set forth, with the exception that the fuel drain and fill and precondition canister steps are not required for gaseous-fueled vehicles. In addition, the supplemental two-diurnal test and the running loss test are not required.
(b) The vehicle test for fuel spitback during fuel dispensing is conducted as a stand-alone test (see § 86.146). This test is not required for gaseous-fueled vehicles.
(c) Ambient temperature levels encountered by the test vehicle shall be not less than 68 °F nor more than 86 °F, unless otherwise specified. If a different ambient temperature is specified for soaking the vehicle, the soak period may be interrupted once for up to 10 minutes to transport the vehicle from one soak area to another, provided the ambient temperature experienced by the vehicle is never below 68 °F. The temperatures monitored during testing must be representative of those experienced by the test vehicle.
(d) The vehicle shall be approximately level during all phases of the test sequence to prevent abnormal fuel distribution.
(e) The supplemental tests for exhaust emissions related to aggressive driving (US06) and air conditioning (SC03) use are conducted as stand-alone tests as described in §§ 86.158 through 86.160. These tests may be performed in any sequence that maintains the appropriate preconditioning requirements as specified in § 86.132.
(f) If tests are invalidated after collection of emission data from previous test segments, the test may be repeated to collect only those data points needed to complete emission measurements. Compliance with emission standards may be determined by combining emission measurements from different test runs. If any emission measurements are repeated, the new measurements supersede previous values.
§ 86.131-96   Vehicle preparation.
(a) For gasoline- and methanol-fueled vehicles prepare the fuel tank(s) for recording the temperature of the prescribed test fuel, as described in § 86.107-96(e).
(b) Provide additional fittings and adapters, as required, to accommodate a fuel drain at the lowest point possible in the tank(s) as installed on the vehicle.
(c) For preconditioning that involves loading the evaporative emission canister(s) with butane, provide valving or other means as necessary to allow purging and loading of the canister(s).
(d) For vehicles to be tested for running loss emissions, prepare the fuel tank(s) for measuring and recording the temperature and pressure of the fuel tank as specified in § 86.107-96 (e) and (f). Measurement of vapor temperature is optional during the running loss test. If vapor temperature is not measured, fuel tank pressure need not be measured.
(e) For vehicles to be tested for running loss emissions, prepare the exhaust system by sealing or plugging all detectable sources of exhaust gas leaks. The exhaust system shall be tested or inspected to ensure that detectable exhaust hydrocarbons are not emitted into the running loss enclosure during the running loss test.
(f) For vehicles to be tested for aggressive driving emissions (US06), provide a throttle position sensing signal that is compatible with the test dynamometer. This signal provides the input information that controls dynamometer dynamic inertia weight adjustments (see §§ 86.108-00(b)(2)(ii) and 86.129-00(f)(2)). If a manufacturer chooses not to implement dynamic inertia adjustments for a portion or all of their product line, this requirement is not applicable.
(g) You may disable any AECDs that have been approved solely for emergency vehicle applications under paragraph (4) of the definition of defeat device in § 86.1803. The emission standards do not apply when any of these AECDs are active.
§ 86.132-00   Vehicle preconditioning.
Applicability. Section 86.132-96 (a) through (c)(1) and (d) through (m) and paragraph (c)(2) of this section are applicable to FTP and evaporative emission testing. Paragraphs (n) and (o) of this section are applicable to vehicles tested for the SFTP supplemental tests of aggressive driving (US06) and air conditioning (SC03). Section 86.132-00 includes text that specifies requirements that differ from § 86.132-96. Where a paragraph in § 86.132-96 is identical and applicable to § 86.132-00, this may be indicated by specifying the corresponding paragraph and the statement “[Reserved]. For guidance see § 86.132-96.”
(a)-(c)(1) [Reserved]. For guidance see § 86.132-96.
(c)(2)(i) Once a test vehicle has completed the refueling and vehicle soak steps specified in § 86.132-96 (b) and (c)(1), these steps may be omitted in subsequent testing with the same vehicle and the same fuel specifications, provided the vehicle remains under laboratory ambient temperature conditions for at least 6 hours before starting the next test. In such cases, each subsequent test shall begin with the preconditioning drive specified in § 86.132-96(c)(1). The test vehicle may not be used to set dynamometer horsepower.
(ii) The SFTP test elements of aggressive driving (US06) and air conditioning (SC03) can be run immediately or up to 72 hours after the official FTP and/or evaporative test sequence without refueling provided the vehicle has remained under laboratory ambient temperature conditions. If the time interval exceeds 72 hours or the vehicle leaves the ambient temperature conditions of the laboratory, the manufacturer must repeat the refueling operation.
(d)-(m) [Reserved]. For guidance see § 86.132-96.
(n) Aggressive Driving Test (US06) Preconditioning. (1) If the US06 test follows the exhaust emission FTP or evaporative testing, the refueling step may be deleted and the vehicle may be preconditioned using the fuel remaining in the tank (see paragraph (c)(2)(ii) of this section). The test vehicle may be pushed or driven onto the test dynamometer. Acceptable cycles for preconditioning are as follows:
(i) Preconditioning may consist of a 505, 866, highway, US06 or SC03 test cycles.
(ii) [Reserved]
(iii) If a manufacturer has concerns about fuel effects on adaptive memory systems, a manufacturer may precondition a test vehicle on test fuel and the US06 cycle. Upon request from a manufacturer, the administrator will also perform the preconditioning with the US06 cycle.
(iv) The preconditioning cycles for the US06 test schedule are conducted at the same ambient test conditions as the certification US06 test.
(2) Following the preconditioning specified in paragraphs (n)(1)(i), (ii), and (iii) of this section, the test vehicle is returned to idle for one to two minutes before the start of the official US06 test cycle.
(o) Air Conditioning Test (SC03) Preconditioning. (1) If the SC03 test follows the exhaust emission FTP or evaporative testing, the refueling step may be deleted and the vehicle may be preconditioned using the fuel remaining in the tank (see paragraph (c)(2)(ii) of this section). The test vehicle may be pushed or driven onto the test dynamometer. Acceptable cycles for preconditioning are as follows:
(i) If the soak period since the last exhaust test element is less than or equal to two hours, preconditioning may consist of a 505, 866, or SC03 test cycles.
(ii) If the soak period since the last exhaust test element is greater than two hours, preconditioning consists of one full Urban Dynamometer Driving Cycle. Manufacturers, at their option, may elect to use the preconditioning in paragraph (o)(1)(i) of this section when the soak period exceeds two hours.
(2) Following the preconditioning specified in paragraphs (o)(1)(i) and (ii) of this section, the test vehicle is turned off, the vehicle cooling fan(s) is turned off, and the vehicle is allowed to soak for 10 minutes prior to the start of the official SC03 test cycle.
(3) The preconditioning cycles for the SC03 air conditioning test and the 10 minute soak are conducted at the same ambient test conditions as the SC03 certification air conditioning test.
§ 86.132-96   Vehicle preconditioning.
(a) Prepare the vehicle for testing as described in this section. Store the vehicle before testing in a way that prevents fuel contamination and preserves the integrity of the fuel system. The vehicle shall be moved into the test area and the following operations performed.
(b)(1) Gasoline- and Methanol-Fueled Vehicles. Drain the fuel tank(s) and fill with test fuel, as specified in § 86.113, to the “tank fuel volume” defined in § 86.082-2. Install the fuel cap(s) within one minute after refueling.
(2) Gaseous-Fueled Vehicles. Fill fuel tanks with fuel that meets the specifications in § 86.113. Fill the fuel tanks to a minimum of 75 percent of service pressure for natural gas-fueled vehicles or a minimum of 75 percent of available fill volume for liquefied petroleum gas-fueled vehicles. However, if you omit the refueling event in paragraph (f) of this section, refuel the vehicles to 85 percent instead of 75 percent. Draining the fuel tanks at the start of the test is not required if the fuel in the tanks already meets the specifications in § 86.113.
(c)(1) Gasoline- and methanol-fueled vehicles shall be soaked for at least 6 hours after being refueled. Petroleum-fueled diesel vehicles and gaseous-fueled vehicles shall be soaked for at least 1 hour after being refueled. Following this soak period, the test vehicle shall be placed, either by being driven or pushed, on a dynamometer and operated through one Urban Dynamometer Driving Schedule (UDDS), specified in § 86.115 and appendix I of this part.
(2) Once a test vehicle has completed the refueling and vehicle soak steps specified in paragraphs (b) and (c)(1) of this section, these steps may be omitted in subsequent testing with the same vehicle and the same fuel specifications, provided the vehicle remains under laboratory ambient temperature conditions for at least 6 hours before starting the next test. In such cases, each subsequent test shall begin with the preconditioning drive specified in this paragraph. The test vehicle may not be used to set dynamometer horsepower.
(d) For unusual circumstances where the need for additional preconditioning is demonstrated by the manufacturer, such preconditioning may be allowed with the advance approval of the Administrator.
(e) The Administrator may also choose to conduct or require to be conducted additional preconditioning to ensure that the evaporative emission control system is stabilized in the case of gasoline-fueled and methanol-fueled vehicles, or to ensure that the exhaust system is stabilized in the case of petroleum- and methanol-fueled diesel vehicles. The preconditioning shall consist of one of the following:
(1) For gasoline- and methanol-fueled vehicles. (i) Additional preconditioning shall consist of no more than 50 miles of mileage accumulation under typical driving conditions, either on the road or on a dynamometer.
(ii) In the case of repeat testing on a flexible-fueled vehicle, in which the test fuel is changed, the following preconditioning procedure shall be used. This additional preconditioning allows the vehicle to adapt to the new fuel before the next test run.
(A) Purge the vehicle's evaporative canister for 60 minutes at 0.8 cfm.
(B) Drain the fuel tank(s) and fill with 3 gallons of the test fuel.
(C) Start the vehicle and allow it to idle for 1 minute.
(D) Drain the fuel tank(s) and fill with the new test fuel to the “tank fuel volume” defined in § 86.082-2. The average temperature of the dispensed fuel shall be less than 60 °F.
(E) Conduct a heat build according to the procedure specified in § 86.133-90.
(F) The vehicle shall be placed, either by being driven or pushed, on a dynamometer and operated through one UDDS, specified in § 86.115 and appendix I of this part.
(G) Following the dynamometer drive, the vehicle shall be turned off for 5 minutes, then restarted and allowed to idle for 1 minute. The vehicle shall then be turned off for 1 minute, and allowed to idle again for 1 minute.
(H) After the vehicle is turned off the last time, it may be tested for evaporative and exhaust emissions, starting with paragraph (a) of this section.
(2) For petroleum-fueled diesel, methanol-fueled diesel, and gaseous-fueled vehicles. The preconditioning shall consist of either of the following:
(i) An initial one hour minimum soak and, one, two, or three driving cycles of the UDDS, as described in paragraph (c) of this section, each followed by a soak of at least one hour with engine off, engine compartment cover closed and cooling fan off. The vehicle may be driven off the dynamometer following each UDDS for the soak period; or
(ii) For abnormally treated vehicles, as defined in § 86.085-2 or § 86.1803-01 as applicable, two Highway Fuel Economy Driving Schedules, found in 40 CFR part 600, appendix I, run in immediate succession, with the road load power set at twice the value obtained from § 86.129-80.
(f) Drain and then fill the vehicle's fuel tank(s) with test fuel, as specified in § 86.113, to the “tank fuel volume” defined in § 86.082-2. Refuel the vehicle within 1 hour after completing the preconditioning drive. Install fuel cap(s) within 1 minute after refueling. Park the vehicle within five minutes after refueling. However, for the following vehicles you may omit this refueling event and instead drive the vehicle off the dynamometer and park it within five minutes after the preconditioning drive:
(1) Diesel-fueled vehicles.
(2) Gaseous-fueled vehicles.
(3) Fuel economy data vehicles.
(4) In-use vehicles subject to testing under § 86.1845.
(g) The vehicle shall be soaked for not less than 12 hours nor more than 36 hours before the cold start exhaust emission test. The soak period starts at the end of the refueling event, or at the end of the previous drive if there is no refueling.
(h) During the soak period for the three-diurnal test sequence described in § 86.130-96, precondition any evaporative canisters as described in this paragraph (h); however, canister preconditioning is not required for fuel economy data vehicles. For vehicles with multiple canisters in a series configuration, the set of canisters must be preconditioned as a unit. For vehicles with multiple canisters in a parallel configuration, each canister must be preconditioned separately. If production evaporative canisters are equipped with a functional service port designed for vapor load or purge steps, the service port shall be used during testing to precondition the canister. In addition, for model year 1998 and later vehicles equipped with refueling canisters, these canisters shall be preconditioned for the three-diurnal test sequence according to the procedure in paragraph (j)(1) of this section. If a vehicle is designed to actively control evaporative or refueling emissions without a canister, the manufacturer shall devise an appropriate preconditioning procedure, subject to the approval of the Administrator.
(1)(i) Prepare the evaporative emission canister for the canister purging and loading operation. The canister shall not be removed from the vehicle, unless access to the canister in its normal location is so restricted that purging and loading can only reasonably be accomplished by removing the canister from the vehicle. Special care shall be taken during this step to avoid damage to the components and the integrity of the fuel system. A replacement canister may be temporarily installed during the soak period while the canister from the test vehicle is preconditioned.
(ii) The canister purge shall be performed with ambient air of humidity controlled to 50±25 grains per pound of dry air. This may be accomplished by purging the canister in a room that is conditioned to this level of absolute humidity. The flow rate of the purge air shall be maintained at a nominal flow rate of 0.8 cfm and the duration shall be determined to provide a total purge volume flow through the canister equivalent to 300 canister bed volume exchanges. The bed volume is based on the volume of adsorbing material in the canister.
(iii) The evaporative emission canister shall then be loaded by sending to the canister an amount of commercial grade butane vapors equivalent to 1.5 times its nominal working capacity. The canister shall be loaded with a mixture composed of 50 percent butane and 50 percent nitrogen by volume at a rate of 15±2 grams butane per hour. If the canister loading at that rate takes longer than 12 hours, a manufacturer may determine a new rate, based on completing the canister loading in no less than 12 hours. The new rate may be used for all subsequent canister loading according to paragraph (h) of this section. The time of initiation and completion of the canister loading shall be recorded.
(iv) The determination of a canister's nominal working capacity shall be based on the average capacity of no less than five canisters that are in a stabilized condition.
(A) For stabilization, each canister must be loaded no less than 10 times and no more than 100 times to 2-gram breakthrough with a 50/50 mixture by volume of butane and nitrogen, at a rate of 15 grams butane per hour. Each canister loading step must be preceded by canister purging with 300 canister bed volume exchanges at 0.8 cfm.
(B) For determining working capacity, each canister must first be purged with 300 canister bed volume exchanges at 0.8 cfm. The working capacity of each canister shall be established by determining the mass of butane required to load the canister from the purged state so that it emits 2 grams of hydrocarbon vapor; the canister must be loaded with a 50/50 mixture by volume of butane and nitrogen, at a rate of 15 grams butane per hour.
(2) For methanol-fueled and flexible-fueled vehicles, canister preconditioning shall be performed with a fuel vapor composition representative of that which the vehicle would generate with the fuel mixture used for the current test. Manufacturers shall develop a procedure to precondition the evaporative canister, if the vehicle is so equipped, for the different fuel. The procedure shall represent a canister loading equivalent to that specified in paragraph (h)(1) of this section and shall be approved in advance by the Administrator.
(i) [Reserved]
(j) During the soak period for the supplemental two-diurnal test sequence described in § 86.130-96, precondition any evaporative canisters using one of the methods described in this paragraph (j); however, canister preconditioning is not required for fuel economy data vehicles. For vehicles with multiple canisters in a series configuration, the set of canisters must be preconditioned as a unit. For vehicles with multiple canisters in a parallel configuration, each canister must be preconditioned separately. In addition, for model year 1998 and later vehicles equipped with refueling canisters, these canisters shall be preconditioned for the supplemental two-diurnal test sequence according to the procedure in paragraph (j)(1) of this section. Canister emissions are measured to determine breakthrough. Breakthrough is here defined as the point at which the cumulative quantity of hydrocarbons emitted is equal to 2 grams.
(1) Butane loading to breakthrough. The following procedure provides for emission measurement in an enclosure. Breakthrough may also be determined by measuring the weight gain of an auxiliary evaporative canister connected downstream of the vehicle's canister, in which case, the following references to the enclosure can be ignored. The auxiliary canister shall be well purged prior to loading. If production evaporative canisters are equipped with a functional service port designed for vapor load or purge steps, the service port shall be used during testing to precondition the canister.
(i) Prepare the evaporative/refueling emission canister for the canister loading operation. The canister shall not be removed from the vehicle, unless access to the canister in its normal location is so restricted that purging and loading can only reasonably be accomplished by removing the canister from the vehicle. Special care shall be taken during this step to avoid damage to the components and the integrity of the fuel system. A replacement canister may be temporarily installed during the soak period while the canister from the test vehicle is preconditioned.
(ii) The evaporative emission enclosure shall be purged for several minutes. Warning: If at any time the concentration of hydrocarbons, of methanol, or of methanol and hydrocarbons exceeds 15,000 ppm C the enclosure should be immediately purged. This concentration provides at least a 4:1 safety factor against the lean flammability limit.
(iii) The FID hydrocarbon analyzer shall be zeroed and spanned immediately prior to the canister loading procedure.
(iv) If not already on, the evaporative enclosure mixing fan shall be turned on at this time.
(v) Place the vehicle in a sealed enclosure and measure emissions with a FID.
(vi)(A) For gasoline-fueled vehicles, load the canister with a mixture composed of 50 percent butane and 50 percent nitrogen by volume at a rate of 40 grams butane per hour.
(B) For methanol-fueled and flexible-fueled vehicles, canister preconditioning shall be performed with a fuel vapor composition representative of that which the vehicle would generate with the fuel mixture used for the current test. Manufacturers shall develop a procedure to precondition the evaporative canister, if the vehicle is so equipped, for the different fuel.
(vii) As soon as the canister reaches breakthrough, the vapor source shall be shut off.
(viii) Reconnect the evaporative/refueling emission canister and restore the vehicle to its normal operating condition.
(2) Load with repeated diurnal heat builds to breakthrough. The following procedure provides for emission measurement in an enclosure. Breakthrough may also be determined by measuring the weight gain of an auxiliary evaporative canister connected downstream of the vehicle's canister, in which case, the following references to the enclosure can be ignored. The auxiliary canister shall be well purged with dry air prior to loading.
(i) The evaporative emission enclosure shall be purged for several minutes. Warning: If at any time the concentration of hydrocarbons, of methanol, or of methanol and hydrocarbons exceeds 15,000 ppm C the enclosure should be immediately purged. This concentration provides at least a 4:1 safety factor against the lean flammability limit.
(ii) The FID hydrocarbon analyzer shall be zeroed and spanned immediately prior to the diurnal heat builds.
(iii) If not already on, the evaporative enclosure mixing fan shall be turned on at this time.
(iv) The fuel tank(s) of the prepared vehicle shall be drained and filled with test fuel, as specified in § 86.113, to the “tank fuel volume” defined in § 86.082-2. The average temperature of the dispensed fuel shall be 60±12 °F (16±7 °C). The fuel tank cap(s) shall be installed within 1 minute after refueling.
(v) Within one hour of being refueled, the vehicle shall be placed, with the engine shut off, in the evaporative emission enclosure. The fuel tank temperature sensor shall be connected to the temperature recording system. A heat source, specified in § 86.107-90(a)(4), shall be properly positioned with respect to the fuel tank(s) and connected to the temperature controller.
(vi) The temperature recording system shall be started.
(vii) The fuel may be artificially heated to the starting diurnal temperature.
(viii) When the fuel temperature reaches at least 69 °F (21 °C), immediately: turn off purge blower (if not already off); close and seal enclosure doors; and initiate measurement of the hydrocarbon level in the enclosure.
(ix) When the fuel temperature reaches 72±2 °F (22±1 °C), start the diurnal heat build.
(x) The fuel shall be heated in such a way that its temperature change conforms to the following function to within ±4 °F (±3 °C):
(xi) As soon as breakthrough occurs or when the fuel temperature reaches 96 °F (36 °C), whichever occurs first, the heat source shall be turned off, the enclosure doors shall be unsealed and opened, and the vehicle fuel tank cap(s) shall be removed. If breakthrough has not occurred by the time the fuel temperature reaches 96 °F (36 °C), the heat source shall be removed from the vehicle, the vehicle shall be removed (with engine still off) from the evaporative emission enclosure and the entire procedure outlined in paragraph (j)(2) of this section shall be repeated until breakthrough occurs.
(xii) After breakthrough occurs, the fuel tank(s) of the prepared vehicle shall be drained and filled with test fuel, as specified in § 86.113, to the “tank fuel volume” defined in § 86.082-2. The fuel shall be stabilized to a temperature within 3 °F of the lab ambient before beginning the driving cycle for the exhaust emission test.
(k) [Reserved]
(l) Vehicles to be tested for exhaust emissions only shall be processed according to §§ 86.135 through 86.137. Vehicles to be tested for evaporative emissions shall be processed in accordance with the procedures in §§ 86.133 through 86.138, starting with § 86.135.
(m) Vehicles to be tested for evaporative emissions with the supplemental two-diurnal test sequence described in § 86.130-96, shall proceed according to §§ 86.135 through 86.137, followed by the supplemental hot soak test (see § 86.138-96(k)) and the supplemental diurnal emission test (see § 86.133-96(p)).
(n) With prior approval of the Administrator, manufacturers may use an alternative canister loading method in lieu of the applicable canister loading method described in the provisions of paragraphs (h), (j)(1) and (j)(2) of this section, provided the alternative method is shown to be equivalent or result in a more fully loaded canister (a canister that has adsorbed an equal or greater amount of hydrocarbon vapors) than the applicable canister loading method required by the provisions of paragraphs (h), (j)(1) and (j)(2) of this section. Additionally, the Administrator may conduct confirmatory certification testing and in-use testing using the alternative canister loading method used by the manufacturer to test applicable certification and/or in-use vehicles or the appropriate method outlined in the provisions of paragraphs (h), (j)(1) and (j)(2) of this section.
§ 86.133-96   Diurnal emission test.
(a)(1) The diurnal emission test for gasoline-, methanol- and gaseous-fueled vehicles consists of three 24-hour test cycles following the hot soak test. Emissions are measured for each 24-hour cycle, with the highest emission level used to determine compliance with the standards specified in subpart A of this part. The Administrator may truncate a test after any 24-hour cycle without affecting the validity of the collected data. Sampling of emissions from the running loss and hot soak tests is not required as preparation for the diurnal emission test. The diurnal emission test may be conducted as part of either the three- diurnal test sequence or the supplemental two-diurnal test sequence, as described in § 86.130-96.
(2) For the full three-diurnal test sequence, the diurnal emission test outlined in paragraphs (b) through (o) of this section follows the high-temperature hot soak test concluded in § 86.138-96(j).
(3) For the supplemental two-diurnal test sequence, the diurnal emission test outlined in paragraph (p) of this section follows the alternate hot soak test specified in § 86.138-96(k). This test is not required for gaseous-fueled vehicles.
(b) The test vehicle shall be soaked for not less than 6 hours nor more than 36 hours between the end of the hot soak test and the start of the diurnal emission test. For at least the last 6 hours of this period, the vehicle shall be soaked at 72°±3 °F. The temperature tolerance may be waived for up to 10 minutes to allow purging of the enclosure or transporting the vehicle into the enclosure at the beginning of the diurnal emission test.
(c) The test vehicle shall be exposed to ambient temperatures cycled according to the profile specified in § 86.133 and appendix II of this part.
(1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time and an average temperature deviation not to exceed 2 °F, where the average deviation is calculated using the absolute value of each measured deviation. In addition, the temperature from the sidewall temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time.
(2) Ambient temperatures shall be measured at least every minute. Temperature cycling shall begin when time = 0 minutes, as specified in paragraph (i)(5) of this section.
(d) The diurnal enclosure shall be purged for several minutes prior to the test. Warning: If at any time the concentration of hydrocarbons, of methanol or of methanol and hydrocarbons exceeds 15,000 ppm C the enclosure should be immediately purged. This concentration provides at least a 4:1 safety factor against the lean flammability limit.
(e) The test vehicle, with the engine shut off and the test vehicle windows and luggage compartment(s) opened, shall be moved into the diurnal enclosure.
(f)-(g) [Reserved]
(h) Prior to sampling for emissions and throughout the period of cycled ambient temperatures, the mixing fan(s) shall circulate the air at a rate of 0.8±0.2 cfm per cubic foot of ambient volume. The mixing fan(s), plus any additional fans if needed, shall also maintain a minimum wind speed of 5 mph (8 km/hr) under the fuel tank of the test vehicle. The Administrator may adjust fan speed and location to ensure sufficient air circulation around the fuel tank. The wind speed requirement may be satisfied by consistently using a fan configuration that has been demonstrated to maintain a broad 5-mph air flow in the vicinity of the vehicle's fuel tank, subject to verification by the Administrator.
(i) Emission sampling may begin as follows:
(1) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately prior to the sampling.
(2) Impingers charged with known volumes of pure deionized water shall be placed in the methanol sampling system (methanol-fueled vehicles only).
(3) Turn off purge blowers (if not already off).
(4) Close and seal enclosure doors (if not already closed and sealed).
(5) Within 10 minutes of closing and sealing the doors, analyze enclosure atmosphere for hydrocarbons and record. This is the initial (time = 0 minutes) hydrocarbon concentration, C HCi , required in § 86.143. Hydrocarbon emissions may be sampled continuously during the test period.
(6) Analyze the enclosure atmosphere for methanol, if applicable, and record. The methanol sampling must start simultaneously with the initiation of the hydrocarbon analysis and continue for 4.0±0.5 minutes. This is the initial methanol concentration, C CH 3 OHi , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses. If the test is conducted in a fixed-volume enclosure that allows airflow into and out of the enclosure, the effect of makeup air dilution must be factored into the analysis.
(j) If testing indicates that a vehicle design may result in fuel temperature responses during enclosure testing that are not representative of in-use summertime conditions, the Administrator may adjust air circulation and temperature during the test as needed to ensure that the test sufficiently duplicates the vehicle's in-use experience.
(k) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately prior to the end of each emission sampling period.
(l) Fresh impingers shall be installed in the methanol collection system immediately prior to the end of each emission measurement, if applicable.
(m) The end of the first, second, and third emission sampling period shall occur 1440±6, 2880±6, 4320±6 minutes, respectively, after the beginning of the initial sampling, as specified in paragraph (i)(5) of this section.
(1) At the end of each emission sampling period, analyze the enclosure atmosphere for hydrocarbons and record. This is the final hydrocarbon concentration, C HCf , required in § 86.143. The emission measurement at the end of each period becomes the initial hydrocarbon concentration, C HCi , of the next emission sampling period.
(2) Analyze the enclosure atmosphere for methanol, if applicable, and record. The methanol sampling must start simultaneously with the initiation of the hydrocarbon analysis and continue for 4.0±0.5 minutes. This is the final (time = 1440 minutes) methanol concentration, C CH 3 OHf , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses. If the test is conducted in a fixed-volume enclosure that allows airflow into and out of the enclosure, the effect of makeup air dilution must be factored into the analysis.
(n) At the end of the temperature cycling period the enclosure doors shall be unsealed and opened, the test vehicle windows and luggage compartments may be closed and the test vehicle, with the engine shut off, shall be removed from the enclosure.
(o) This completes the full three-diurnal evaporative emission test sequence described in § 86.130-96.
(p) For the supplemental two-diurnal test sequence described in § 86.130-96, the following steps shall be performed in lieu of the steps described in paragraphs (b) through (n) of this section.
(1) For the supplemental two-diurnal test sequence, the test vehicle shall be soaked for not less than 6 hours nor more than 36 hours between the end of the hot soak test described in § 86.138-96(k), and the start of the two-diurnal emission test. For at least the last 6 hours of this period, the vehicle shall be soaked at 72±3 °F.
(2) The vehicle shall be tested for diurnal emissions according to the procedures specified in paragraphs (c) through (n) of this section, except that the test includes only two 24-hour periods. Therefore the end of the first and second emission sampling periods shall occur 1440±6 and 2880±6 minutes, respectively, after the initial sampling.
(3) This completes the supplemental two-diurnal test sequence for evaporative emission measurement.
§ 86.134-96   Running loss test.
(a) Overview. Gasoline- and methanol-fueled vehicles are to be tested for running loss emissions during simulated high-temperature urban driving; this test is not required for gaseous-fueled vehicles. During operation, tank temperatures are controlled according to a prescribed profile to simulate in-use conditions. If the vehicle is determined to have exceeded the standard before the end of the running loss test, the test may be terminated without invalidating the data. The test can be run either in a sealed enclosure or with the point-source method, as specified in paragraph (g) of this section. Measurement of vapor temperature is optional during the running loss test; however, if testing by the Administrator shows that a vehicle has exceeded an emission standard without measurement of vapor temperatures, the manufacturer may, utilizing its own resources, conduct subsequent testing on that vehicle to determine if the exceedance is attributable to inadequate control of vapor temperatures.
(b) Driving schedule. Conduct the running loss test by operating the test vehicle through one Urban Dynamometer Driving Schedule (UDDS), a 2-minute idle, two New York City Cycles, another 2-minute idle, another UDDS, then another 2-minute idle (see § 86.115 and appendix I of this part). Fifteen seconds after the engine starts, place the transmission in gear. Twenty seconds after the engine starts, begin the initial vehicle acceleration of the driving schedule. The transmission shall be operated according to the specifications of § 86.128 during the driving cycles.
(c) Dynamometer operation. (1) The exhaust from the vehicle must be routed outside the test cell or enclosure. Exhaust gases may, but need not, be collected and sampled.
(2) Provisions of § 86.135-90(c) shall apply.
(3) Practice runs over the prescribed driving schedule may not be performed at test point.
(4) Provisions of § 86.135-90 (e) and (f) shall apply.
(5) If the dynamometer horsepower must be adjusted manually, it shall be set within 1 hour prior to the running loss test phase. The test vehicle shall not be used to make this adjustment. Dynamometers using automatic control of preselectable power settings may be set any time prior to the beginning of the emissions test.
(6) Dynamometer roll or shaft revolutions shall be used to determine the actual driving distance for the running loss test, D RL , required in § 86.143. The revolutions shall be measured on the same roll or shaft used for measuring the vehicle's speed.
(7) Provisions of § 86.135-90(i) shall apply.
(8) The test run may be stopped if a warning light or gauge indicates that the vehicle's engine coolant has overheated.
(d) Engine starting and restarting. (1) Provisions of § 86.136-90(a) shall apply.
(2) If the vehicle does not start after the manufacturer's recommended cranking time (or 10 continuous seconds in the absence of a manufacturer's recommendation), cranking shall cease for the period recommended by the manufacturer (or 10 seconds in the absence of a manufacturer's recommendation). This may be repeated for up to three start attempts. If the vehicle does not start after three attempts, the reason for failure to start shall be determined. If failure to start is an operational error, the vehicle shall be rescheduled for testing, starting with the soak period immediately preceding the running loss test.
(3) If failure to start is caused by a vehicle malfunction, corrective action of less than 30 minutes duration may be taken (according to § 86.090-25), and the test continued, provided that the ambient conditions to which the vehicle is exposed are maintained at 95±5 °F (35±3 °C). When the engine starts, the timing sequence of the driving schedule shall begin. If failure to start is caused by vehicle malfunction and the vehicle cannot be started, the test shall be voided, the vehicle removed from the dynamometer, and corrective action may be taken according to § 86.090-25. The reason for the malfunction (if determined) and the corrective action taken shall be reported to the Administrator.
(4) Provisions of § 86.136-90(e) shall apply.
(e) Pressure checks. No pressure checks of the evaporative system shall be allowed. Under no circumstances will any changes/repairs to the evaporative emissions control system be allowed.
(f) Temperature stabilization. Immediately after the hot transient exhaust emission test, the vehicle shall be soaked in a temperature controlled area for a maximum of 6 hours until the fuel temperature is stabilized. The fuel may be heated or cooled to stabilize fuel temperatures, but the fuel heating rate must not exceed 5 °F in any 1-hour interval during the soak period. A manufacturer may use a faster heating rate or a longer period for stabilizing fuel temperatures if the needed heating cannot be easily accomplished in the 6-hour period, subject to Administrator approval.
(1) Fuel temperatures must be held at 95 ±3 °F for at least one hour before the start of the running loss test.
(2) If a vehicle's fuel temperature profile has an initial temperature lower than 95 °F, as described in § 86.129-94(d)(7)(v), the fuel in the test vehicle must be stabilized to within 3 °F of that temperature for at least one hour before the start of the running loss test.
(g) Running loss test. The running loss test may be conducted either by the enclosure method, or by the point-source method.
(1) Enclosure method. (i) The running loss enclosure shall be purged for several minutes immediately prior to the test. Warning: If at any time the concentration of hydrocarbons, of methanol, or of methanol and hydrocarbons exceeds 15,000 ppm C the enclosure should be immediately purged. This concentration provides at least a 4:1 safety factor against the lean flammability limit.
(ii) The FID hydrocarbon analyzer shall be zeroed and spanned immediately prior to the test.
(iii) If not already on, the running loss enclosure mixing fan(s) shall be turned on at this time. Throughout the test, the mixing fan(s) shall circulate the air at a rate of at least 1.0 cfm per cubic foot of ambient volume.
(iv) The test vehicle, with the engine off, shall be moved onto the dynamometer in the running loss enclosure. The vehicle engine compartment cover shall be unlatched, but closed as much as possible, allowing for the air intake equipment specified in paragraph (g)(1)(vii) of this section. The vehicle engine compartment cover may be closed if alternate routing is found for the air intake equipment. Any windows, doors, and luggage compartments shall be closed. A window may be opened to direct cooling air into the passenger compartment of the vehicle, if the vehicle is not equipped with its own air conditioning.
(v) Fans shall be positioned as described in §§ 86.107-96 (d) and (h).
(vi) Set vehicle air conditioning controls as described in 40 CFR 1066.835.
(vii) Connect the air intake equipment to the vehicle, if applicable. This connection shall be made to minimize leakage.
(viii) The temperature and pressure recording systems shall be started. Measurement of vapor temperature is optional during the running loss test. If vapor temperature is not measured, fuel tank pressure need not be measured.
(ix) Turn off purge blowers (if not already off).
(x) The temperature of the liquid fuel shall be monitored and recorded at least every 15 seconds with the temperature recording system specified in § 86.107-96(e).
(xi) Close and seal the enclosure doors.
(xii) When the ambient temperature is 95±5 °F (35±3 °C) and the fuel has been stabilized according to paragraph (f) of this section, the running loss test may begin. Measure the initial ambient temperature and pressure.
(A) Analyze enclosure atmosphere for hydrocarbons and record. This is the initial (time = 0 minutes) hydrocarbon concentration, C HCi , required in § 86.143. Hydrocarbon emissions may be sampled continuously during the test period.
(B) Analyze the enclosure atmosphere for methanol, if applicable, and record. The methanol sampling must start simultaneously with the initiation of the hydrocarbon analysis and continue for 4.0±0.5 minutes. This is the initial (time = 0 minutes) methanol concentration, C CH 3 OHi , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses.
(xiii) Start the engine and begin operation of the vehicle over the drive cycle specified in paragraph (b) of this section.
(xiv) The ambient temperature shall be maintained at 95±5 °F (95±2 °F on average) during the running loss test, measured at the inlet to the cooling fan in front of the vehicle; it shall be recorded at least every 60 seconds.
(xv) The fuel temperature during the dynamometer drive shall be controlled to match the fuel tank temperature profile determined in § 86.129. Measured fuel temperatures must be within ±3 °F of the target profile throughout the test run. Vapor temperatures, if measured, must be within ±5 °F of the target profile during the first 4186 seconds of the running loss test, and within ±3 °F for the remaining 120 seconds of the test run. For any vehicle complying with the test standards, vapor temperatures may be higher than the specified tolerances without invalidating test results. For testing by the Administrator, vapor temperatures may be lower than the specified tolerances without invalidating test results. If the test vehicle has more than one fuel tank, the temperatures for both fuel tanks shall follow the target profiles determined in § 86.129. The control system shall be tuned and operated to provide smooth and continuous tank temperature profiles that are representative of the on-road profiles.
(xvi) Fuel tank pressure may exceed 10 inches of water during the running loss test only if the manufacturer demonstrates that vapor would not be vented to the atmosphere upon fuel cap removal. Note that this allows for temporary pressure exceedances for vehicles whose tank pressure otherwise remains below 10 inches of water.
(xvii) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately prior the end of the test.
(xviii) Fresh impingers shall be installed in the methanol collection system immediately prior to the end of the test, if applicable.
(xix) The running loss test ends with the completion of the third 2-minute idle period.
(xx) At the end of the running loss test:
(A) Analyze the enclosure atmosphere for hydrocarbons and record. This is the final hydrocarbon concentration, C HCf , required in § 86.143.
(B) Analyze the enclosure atmosphere for methanol, if applicable, and record. The methanol sampling must start prior to the end of the test and continue for 4.0±0.5 minutes. The methanol sampling must be completed within 2 minutes after the end of the running loss test. This is the final methanol concentration, C CH 3 OHf , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses.
(C) Turn off all the fans specified in § 86.107-96(d). Also, the time that the vehicle's engine compartment cover is open for removal of air intake equipment, if applicable, shall be minimized to avoid loss of heat from the engine compartment.
(xxi) Turn off any CVS apparatus (if not already turned off).
(2) Point-source method. (i) The test vehicle, with the engine off, shall be moved onto the dynamometer. The vehicle engine compartment cover and any windows, doors, and luggage compartments shall be closed.
(ii) Fans shall be positioned as described in §§ 86.135-90(b) and 86.107-96(d).
(iii) The running loss vapor vent collection system shall be properly positioned at the potential fuel vapor vents or leaks of the vehicle's fuel system. Typical vapor vents for current fuel systems are the ports of the evaporative emission canister and the pressure relief vent of the fuel tank (typically integrated into the fuel tank cap).
(iv) The running loss vapor vent collection system may be connected to a PDP-CVS or CFV-CVS bag collection system. Otherwise, running loss vapors shall be sampled continuously with analyzers meeting the requirements of § 86.107-96(b).
(v) Fans shall be positioned as described in § 86.107-96(d).
(vi) Set vehicle air conditioning controls as described in 40 CFR 1066.835.
(vii) The temperature and pressure recording systems shall be started. Measurement of vapor temperature is optional during the running loss test. If vapor temperature is not measured, fuel tank pressure need not be measured.
(viii) The temperature of the liquid fuel shall be monitored and recorded at least every 15 seconds with the temperature recording system specified in § 86.107-96(e).
(ix) When the ambient temperature is 95±5 °F (35±3 °C) and the fuel tank temperature is 95±3 °F the running loss test may begin.
(x) The ambient temperature shall be maintained at 95±5 °F (95±2 °F on average) during the running loss test, measured at the inlet to the cooling fan in front of the vehicle; it shall be recorded at least every 60 seconds.
(xi) Fuel temperatures shall be controlled according to the specifications of paragraph (g)(1)(xv) of this section.
(xii) The tank pressure requirements described in paragraph (g)(1)(xvi) of this section apply also to running loss testing by the point source method.
(xiii) The running loss test ends with completion of the third 2-minute idle period.
(xiv) If emissions are collected in bags, the sample bags must be analyzed within 20 minutes of their respective sample collection phases, as described in § 86.137-94(b)(15). The results of the analysis are used in § 86.143 to calculate the mass of hydrocarbons emitted.
(xv) At the end of the running loss test, turn off all the fans specified in § 86.107-96(d).
(3) With prior approval of the Administrator, manufacturers may use an alternative running loss test procedure, provided the alternative test procedure is shown to yield equivalent or superior emission results (in terms of quality control, accuracy and repeatability) for the running loss, hot soak and diurnal portions of the three diurnal-plus-hot-soak test sequence. Additionally, the Administrator may conduct certification and in-use testing using the test procedures outlined in paragraph (g)(1) of this section, paragraph (g)(2) of this section or the alternative running loss test procedure as approved for a specific vehicle.
(4) High-altitude testing. For testing under high-altitude conditions, decrease the target ambient and fuel temperatures by 5 °F. For example, the fuel temperature profile should be adjusted downward based on a nominal starting temperature of 90 °F, and the nominal temperature in the enclosure should be 90 °F.
(h) Following the completion of the running loss drive, the vehicle may be tested for hot soak emissions as specified in § 86.138-96.
§ 86.135-12   Dynamometer procedure.
(a) Overview. The dynamometer run consists of two tests, a “cold” start test, after a minimum 12-hour and a maximum 36-hour soak according to the provisions of §§ 86.132 and 86.133, and a “hot” start test following the “cold” start by 10 minutes. Engine startup (with all accessories turned off), operation over the UDDS, and engine shutdown make a complete cold start test. Engine startup and operation over the first 505 seconds of the driving schedule complete the hot start test. The exhaust emissions are diluted with ambient air in the dilution tunnel as shown in Figure B94-5 and Figure B94-6. A dilution tunnel is not required for testing vehicles waived from the requirement to measure particulates. Six particulate samples are collected on filters for weighing; the first sample plus backup is collected during the first 505 seconds of the cold start test; the second sample plus backup is collected during the remainder of the cold start test (including shutdown); the third sample plus backup is collected during the hot start test. Continuous proportional samples of gaseous emissions are collected for analysis during each test phase. For gasoline-fueled, natural gas-fueled and liquefied petroleum gas-fueled Otto-cycle vehicles, the composite samples collected in bags are analyzed for THC, CO, CO 2 , CH 4 , NO X , and N 2 O. For petroleum-fueled diesel-cycle vehicles (optional for natural gas-fueled, liquefied petroleum gas-fueled and methanol-fueled diesel-cycle vehicles), THC is sampled and analyzed continuously according to the provisions of § 86.110-94. Parallel samples of the dilution air are similarly analyzed for THC, CO, CO 2 , CH 4 , NO X , and N 2 O. For natural gas-fueled, liquefied petroleum gas-fueled and methanol-fueled vehicles, bag samples are collected and analyzed for THC (if not sampled continuously), CO, CO 2 , CH 4 , NO X , and N 2 O. For methanol-fueled vehicles, methanol and formaldehyde samples are taken for both exhaust emissions and dilution air (a single dilution air formaldehyde sample, covering the total test period may be collected). For ethanol-fueled vehicles, methanol, ethanol, acetaldehyde, and formaldehyde samples are taken for both exhaust emissions and dilution air (a single dilution air formaldehyde sample, covering the total test period may be collected). Parallel bag samples of dilution air are analyzed for THC, CO, CO 2 , CH 4 , NO X , and N 2 O.
(b) During dynamometer operation, a fixed speed cooling fan shall be positioned so as to direct cooling air to the vehicle in an appropriate manner with the engine compartment cover open. In the case of vehicles with front engine compartments, the fan shall be squarely positioned within 12 inches (30.5 centimeters) of the vehicle. In the case of vehicles with rear engine compartments (or if special designs make the above impractical), the cooling fan shall be placed in a position to provide sufficient air to maintain vehicle cooling. The fan capacity shall normally not exceed 5300 cfm (2.50 m 3 /sec). However, if the manufacturer can show that during field operation the vehicle receives additional cooling, and that such additional cooling is needed to provide a representative test, the fan capacity may be increased, additional fans used, variable speed fan(s) may be used, and/or the engine compartment cover may be closed, if approved in advance by the Administrator. For example, the hood may be closed to provide adequate air flow to an intercooler through a factory installed hood scoop. Additionally, the Administrator may conduct certification, fuel economy and in-use testing using the additional cooling set-up approved for a specific vehicle.
(c) The vehicle speed as measured from the dynamometer rolls shall be used. A speed vs. time recording, as evidence of dynamometer test validity, shall be supplied on request of the Administrator.
(d) Practice runs over the prescribed driving schedule may be performed at test point, provided an emission sample is not taken, for the purpose of finding the appropriate throttle action to maintain the proper speed-time relationship, or to permit sampling system adjustment. Both smoothing of speed variations and excessive accelerator pedal perturbations are to be avoided. When using two-roll dynamometers a truer speed-time trace may be obtained by minimizing the rocking of the vehicle in the rolls; the rocking of the vehicle changes the tire rolling radius on each roll. This rocking may be minimized by restraining the vehicle horizontally (or nearly so) by using a cable and winch.
(e) The drive wheel tires may be inflated up to a gauge pressure of 45 psi (310 kPa) in order to prevent tire damage. The drive wheel tire pressure shall be reported with the test results.
(f) If the dynamometer has not been operated during the 2-hour period immediately preceding the test, it shall be warmed up for 15 minutes by operating at 30 mph (48 kph) using a non-test vehicle or as recommended by the dynamometer manufacturer.
(g) If the dynamometer horsepower must be adjusted manually, it shall be set within 1 hour prior to the exhaust emissions test phase. The test vehicle shall not be used to make this adjustment. Dynamometers using automatic control of pre-selectable power settings may be set anytime prior to the beginning of the emissions test.
(h) The driving distance, as measured by counting the number of dynamometer roll or shaft revolutions, shall be determined for the transient cold start, stabilized cold start, and transient hot start phases of the test. The revolutions shall be measured on the same roll or shaft used for measuring the vehicle's speed.
(i) Four-wheel drive and all-wheel drive vehicles may be tested either in a four-wheel drive or a two-wheel drive mode of operation. In order to test in the two-wheel drive mode, four-wheel drive and all-wheel drive vehicles may have one set of drive wheels disengaged; four-wheel and all-wheel drive vehicles which can be shifted to a two-wheel mode by the driver may be tested in a two-wheel drive mode of operation.
§ 86.135-90   Dynamometer procedure.
(a) The dynamometer run consists of two tests—a “cold” start test, after a minimum 12-hour and a maximum 36-hour soak according to the provisions of §§ 86.132 and 86.133, and a “hot” start test following the “cold” start by 10 minutes. Engine startup (with all accessories turned off), operation over the UDDS and engine shutdown make a complete cold-start test. Engine startup and operation over the first 505 seconds of the driving schedule complete the hot start test. The exhaust emissions are diluted with ambient air in the dilution tunnel as shown in Figure B94-5 and Figure B94-6. A dilution tunnel is not required for testing vehicles waived from the requirement to measure particulate matter. Six particulate samples are collected on filters for weighing; the first sample plus backup is collected during the first 505 seconds of the cold-start test; the second sample plus backup is collected during the remainder of the cold-start test (including shutdown); the third sample plus backup is collected during the hot start test. Continuous or batch proportional samples of gaseous emissions are collected for analysis during each test phase. Use the following measurement procedures for each type of engine:
(1) For gasoline-fueled, natural gas-fueled and liquefied petroleum gas-fueled Otto-cycle vehicles, the composite samples collected in bags are analyzed for THC, CO, CO 2 , CH 4 , and NO X .
(2) For petroleum-fueled diesel-cycle vehicles (optional for natural gas-fueled, liquefied petroleum gas-fueled and methanol-fueled diesel-cycle vehicles), THC is sampled and analyzed continuously according to the provisions of § 86.110. Parallel samples of the dilution air are similarly analyzed for THC, CO, CO 2 , CH 4 , and NO X .
(3) For natural gas-fueled, liquefied petroleum gas-fueled and methanol-fueled vehicles, bag samples are collected and analyzed for THC (if not sampled continuously), CO, CO 2 , CH 4 , and NO X .
(4) For methanol-fueled vehicles, methanol and formaldehyde samples are taken for both exhaust emissions and dilution air (a single dilution air formaldehyde sample, covering the total test period may be collected). Parallel bag samples of dilution air are analyzed for THC, CO, CO 2 , CH 4 , and NO X .
(b) During dynamometer operation, a fixed speed cooling fan shall be positioned so as to direct cooling air to the vehicle in an appropriate manner with the engine compartment cover open. In the case of vehicles with front engine compartments, the fan shall be squarely positioned within 12 inches (30.5 centimeters) of the vehicle. In the case of vehicles with rear engine compartments (or if special designs make the above impractical), the cooling fan shall be placed in a position to provide sufficient air to maintain vehicle cooling. The fan capacity shall normally not exceed 5300 cfm (2.50 m3/sec). If however, the manufacturer can show that during field operation the vehicle receives additional cooling, and that such additional cooling is needed to provide a representative test, the fan capacity may be increased, additional fans used, variable speed fan(s) may be used, and/or the engine compartment cover may be closed if approved in advance by the Administrator. For example, the hood may be closed to provide adequate air flow to an intercooler through a factory installed hood scoop. Additionally, the Administrator may conduct certification, fuel economy and in-use testing using the additional cooling set-up approved for a specific vehicle.
(c) The vehicle speed as measured from the dynamometer rolls shall be used. A speed vs. time recording, as evidence of dynamometer test validity, shall be supplied on request of the Administrator.
(d) Practice runs over the prescribed driving schedule may be performed at test point, provided an emission sample is not taken, for the purpose of finding the appropriate throttle action to maintain the proper speed-time relationship, or to permit sampling system adjustment. Both smoothing of speed variations and excessive accelerator pedal perturbations are to be avoided. When using two-roll dynamometers a truer speed-time trace may be obtained by minimizing the rocking of the vehicle in the rolls; the rocking of the vehicle changes the tire rolling radius on each roll. This rocking may be minimized by restraining the vehicle horizontally (or nearly so) by using a cable and winch.
(e) The drive wheel tires may be inflated up to a gauge pressure of 45 psi (310 kPa) in order to prevent tire damage. The drive wheel tire pressure shall be reported with the test results.
(f) lf the dynamometer has not been operated during the 2-hour period immediately preceding the test, it shall be warmed up for 15 minutes by operating at 30 mph (48 kph) using a non-test vehicle or as recommended by the dynamometer manufacturer.
(g) If the dynamometer horsepower must be adjusted manually, it shall be set within 1 hour prior to the exhaust emissions test phase. The test vehicle shall not be used to make this adjustment. Dynamometers using automatic control of preselectable power settings may be set anytime prior to the beginning of the emissions test.
(h) The driving distance, as measured by counting the number of dynamometer roll or shaft revolutions, shall be determined for the transient cold start, stabilized cold start, and transient hot start phases of the test. The revolutions shall be measured on the same roll or shaft used for measuring the vehicle's speed.
(i) Four-wheel drive and all-wheel drive vehicles may be tested either in a four-wheel drive or a two-wheel drive mode of operation. In order to test in the two-wheel drive mode, four-wheel drive and all-wheel drive vehicles may have one set of drive wheels disengaged; four-wheel and all-wheel drive vehicles which can be shifted to a two-wheel mode by the driver may be tested in a two-wheel drive mode of operation.
§ 86.136-90   Engine starting and restarting.
(a) Otto-cycle vehicles. Paragraph (a) of this section applies to Otto-cycle vehicles.
(1) The engine shall be started according to the manufacturer's recommended starting procedures in the owner's manual. The initial 20-second idle period shall begin when the engine starts.
(2) Choke operation: (i) Vehicles equipped with automatic chokes shall be operated according to the manufacturer's operating instructions in the owner's manual, including choke setting and “kick-down” from cold fast idle.
(ii) Vehicles equipped with manual chokes shall be operated according to the manufacturer's operating instructions in the owner's manual.
(3) The transmission shall be placed in gear 15 seconds after the engine is started. If necessary, braking may be employed to keep the drive wheels from turning.
(4) The operator may use the choke, accelerator pedal, etc., where necessary to keep the engine running.
(5) If the manufacturer's operating instructions in the owner's manual do not specify a warm engine starting procedure, the engine (automatic and manual-choke engines) shall be started by depressing the accelerator pedal about half way and cranking the engine until it starts.
(b) Diesel vehicles. The engine shall be started according to the manufacturers recommended starting procedures in the owners manual. The initial 20-second idle period shall begin when the engine starts. The transmission shall be placed in gear 15 seconds after the engine is started. If necessary, braking may be employed to keep the drive wheels from turning.
(c) If the vehicle does not start after the manufacturer's recommended cranking time (or 10 continuous seconds in the absence of a manufacturer's recommendation), cranking shall cease for the period recommended by the manufacturer (or 10 seconds in the absence of a manufacturer's recommendation). This may be repeated for up to three start attempts. If the vehicle does not start after three attempts, the reason for failure to start shall be determined. The gas flow measuring device on the constant volume sampler (usually a revolution counter) or CFV (and the hydrocarbon integrator and particulate sampling system when testing petroleum-fueled diesel vehicles and the particulate sampling system when testing methanol-fueled diesel vehicles, see § 86.137) shall be turned off and the sampler selector valves, including the methanol sampler, placed in the “standby” position during this diagnostic period. In addition, either the CVS should be turned off, or the exhaust tube disconnected from the tailpipe during the diagnostic period. If failure to start is an operational error, the vehicle shall be rescheduled for testing from a cold start.
(d) If the engine “false starts” the operator shall repeat the recommended starting procedure (such as resetting the choke, etc.).
(e) Stalling. (1) If the engine stalls during an idle period, the engine shall be restarted immediately and the test continued. If the engine cannot be started soon enough to allow the vehicle to follow the next acceleration as prescribed, the driving schedule indicator shall be stopped. When the vehicle restarts, the driving schedule indicator shall be reactivated.
(2) If the engine stalls during some operating mode other than idle, the driving schedule indicator shall be stopped, the vehicle shall then be restarted and accelerated to the speed required at that point in the driving schedule and the test continued. During acceleration to this point, shifting shall be performed in accordance with § 86.128.
(3) If the vehicle will not restart within one minute, the test shall be voided, the vehicle removed from the dynamometer, corrective action taken, and the vehicle rescheduled for test. The reason for the malfunction (if determined) and the corrective action taken shall be reported to the Administrator.
§ 86.137-94   Dynamometer test run, gaseous and particulate emissions.
Section 86.137-94 includes text that specifies requirements that differ from § 86.137-90. Where a paragraph in § 86.137-90 is identical and applicable to § 86.137-94, this may be indicated by specifying the corresponding paragraph and the statement “[Reserved]. For guidance see § 86.137-90.” Where a corresponding paragraph of § 86.137-90 is not applicable, this is indicated by the statement “[Reserved].”
(a) General. The dynamometer run consists of two tests, a cold start test, after a minimum 12-hour and a maximum 36-hour soak according to the provisions of § 86.132, and a hot start test following the cold start test by 10 minutes. The vehicle shall be stored prior to the emission test in such a manner that precipitation (e.g., rain or dew) does not occur on the vehicle. The complete dynamometer test consists of a cold start drive of 7.5 miles (12.1 km) and simulates a hot start drive of 7.5 miles (12.1 km). The vehicle is allowed to stand on the dynamometer during the 10 minute time period between the cold and hot start tests. The cold start test is divided into two periods. The first period, representing the cold start “transient” phase, terminates at the end of the deceleration which is scheduled to occur at 505 seconds of the driving schedule. The second period, representing the “stabilized” phase, consists of the remainder of the driving schedule including engine shutdown. The hot start test, similarly, consists of two periods. The first period, representing the hot start “transient” phase, terminates at the same point in driving schedule as the first period of the cold start test. The second period of the hot start test, “stabilized” phase, is assumed to be identical to the second period of the cold start test. Therefore, the hot start test terminates after the first period (505 seconds) is run.
(b) The following steps shall be taken for each test:
(1) Place drive wheels of vehicle on dynamometer without starting engine.
(2) Open the vehicle engine compartment cover and position the cooling fan.
(3) For all vehicles, with the sample selector valves in the “standby” position, connect evacuated sample collection bags to the dilute exhaust and dilution air sample collection systems.
(4) For methanol-fueled vehicles, with the sample selector valves in the “standby” position, insert fresh sample collection impingers into the methanol sample collection system, fresh impingers or a fresh cartridge into the formaldehyde sample collection system and fresh impingers (or a single cartridge for formaldehyde) into the dilution air sample collection systems for methanol and formaldehyde (background measurements of methanol and formaldehyde may be omitted and concentrations assumed to be zero for calculations in § 86.144).
(5) Start the CVS (if not already on), the sample pumps (except the particulate sample pump, if applicable), the temperature recorder, the vehicle cooling fan, and the heated THC analysis recorder (diesel-cycle only). (The heat exchanger of the constant volume sampler, if used, petroleum-fueled diesel-cycle THC analyzer continuous sample line and filter, methanol-fueled vehicle THC, methanol and formaldehyde sample lines, if applicable, should be preheated to their respective operating temperatures before the test begins).
(6) Adjust the sample flow rates to the desired flow rate and set the gas flow measuring devices to zero.
(i) For gaseous bag samples (except THC samples), the minimum flow rate is 0.17 cfm (0.08 1/sec).
(ii) For THC samples, the minimum FID (or HFID in the case of diesel-cycle and methanol-fueled Otto-cycle vehicles) flow rate is 0.066 cfm (0.031 1/sec).
(iii) For methanol samples, the flow rates shall be set such that the system meets the design criteria of § 86.109 and § 86.110. For samples in which the concentration in the primary impinger exceeds 0.5 mg/l, it is recommended that the mass of methanol collected in the secondary impinger not exceed ten percent of the total mass collected. For samples in which the concentration in the primary impinger does not exceed 0.5 mg/l, analysis of the secondary impingers is not necessary.
(iv) For formaldehyde samples, the flow rates shall be set such that the system meets the design criteria of § 86.109 and § 86.110. For impinger samples in which the concentration of formaldehyde in the primary impinger exceeds 0.1 mg/l, it is recommended that the mass of formaldehyde collected in the secondary impinger not exceed ten percent of the total mass collected. For samples in which the concentration in the primary impinger does not exceed 0.1 mg/l, analysis of the secondary impingers is not necessary.
(7) Attach the exhaust tube to the vehicle tailpipe(s).
(8) Carefully install a particulate sample filter into each of the filter holders. The filters must be handled only with forceps or tongs. Rough or abrasive filter handling will result in erroneous weight determination.
(9) Start the gas flow measuring device, position the sample selector valves to direct the sample flow into the “transient” exhaust sample bag, the “transient” methanol exhaust sample, the “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol dilution air sample and the “transient” formaldehyde dilution air sample (turn on the petroleum-fueled diesel-cycle THC analyzer system integrator, mark the recorder chart, start particulate sample pump No. 1, and record both gas meter or flow measurement instrument readings, if applicable), turn the key on, and start cranking the engine.
(10) Fifteen seconds after the engine starts, place the transmission in gear.
(11) Twenty seconds after the engine starts, begin the initial vehicle acceleration of the driving schedule.
(12) Operate the vehicle according to the Urban Dynamometer Driving Schedule (§ 86.115).
During particulate testing, adjust the flow rate through the particulate sample probe to maintain a constant value within ±5 percent of the set flow rate. Record the average temperature and pressure at the gas meter or flow instrument inlet. If the set flow rate cannot be maintained because of high particulate loading on the filter, the test shall be terminated. The test shall be rerun using a lower flow rate, or larger diameter filter, or both.
(13) At the end of the deceleration which is scheduled to occur at 505 seconds, simultaneously switch the sample flows from the “transient” bags and samples to the “stabilized” bags and samples, switch off gas flow measuring device No. 1, switch off the No. 1 petroleum-fueled diesel hydrocarbon integrator and the No. 1 particulate sample pump, mark the petroleum-fueled diesel hydrocarbon recorder chart, and close valves isolating particulate filter No. 1, if applicable, start gas flow measuring device No. 2, and start the petroleum-fueled diesel hydrocarbon integrator No. 2 and the No. 2 particulate sample pump and open valves isolating particulate filter No. 2, if applicable. Before the acceleration which is scheduled to occur at 510 seconds, record the measured roll or shaft revolutions and reset the counter or switch to a second counter. As soon as possible transfer the “transient” exhaust and dilution air samples to the analytical system and process the samples according to § 86.140 obtaining a stabilized reading of the bag exhaust sample on all analyzers within 20 minutes of the end of the sample collection phase of the test. Obtain methanol and formaldehyde sample analyses, if applicable, within 24 hours of the end of the sample collection phase of the test.
(14) Turn the engine off 2 seconds after the end of the last deceleration (at 1,369 seconds).
(15) Five seconds after the engine stops running, simultaneously turn off gas flow measuring device No. 2 and if applicable, turn off the hydrocarbon integrator No. 2, mark the hydrocarbon recorder chart, turn off the No. 2 particulate sample pump and close the valves isolating particulate filter No. 2, and position the sample selector valves to the “standby” position (and open the valves isolating particulate filter No. 1, if applicable). Record the measured roll or shaft revolutions (both gas meter or flow measurement instrumentation readings), and reset the counter. As soon as possible, transfer the “stabilized” exhaust and dilution air samples to the analytical system and process the samples according to § 86.140, obtaining a stabilized reading of the exhaust bag sample on all analyzers within 20 minutes of the end of the sample collection phase of the test. Obtain methanol and formaldehyde sample analyses, if applicable, within 24 hours of the end of the sample period. (If it is not possible to perform analysis on the methanol and formaldehyde samples within 24 hours, the samples should be stored in a dark cold (4-10 °C) environment until analysis. The samples should be analyzed within fourteen days.) If applicable, carefully remove both pairs of particulate sample filters from their respective holders, and place each in a separate petri dish, and cover.
(16) Immediately after the end of the sample period, turn off the cooling fan and close the engine compartment cover.
(17) Turn off the CVS or disconnect the exhaust tube from the tailpipe(s) of the vehicle.
(18) Repeat the steps in paragraphs (b)(2) through (b)(12) of this section for the hot start test, except only two evacuated sample bags, two methanol sample impingers, two formaldehyde sample impingers, and one pair of particulate sample filters, as appropriate, are required. The step in paragraph (b)(9) of this section shall begin between 9 and 11 minutes after the end of the sample period for the cold-start test.
(19) At the end of the deceleration scheduled to occur at 505 seconds, simultaneously turn off gas flow measuring device No. 1 (and the petroleum-fueled diesel hydrocarbon integrator No. 1; mark the petroleum-fueled diesel hydrocarbon recorder chart and turn off the No. 1 particulate sample pump, if applicable) and position the sample selector valve to the “standby” position. (Engine shutdown is not part of the hot start test sample period.) Record the measured roll or shaft revolutions (and the No. 1 gas meter reading or flow measurement instrument). Carefully remove the third pair of particulate sample filters from the holder and place in a clean petri dish and cover, if applicable.
(20) As soon as possible, transfer the hot start “transient” exhaust and dilution air samples to the analytical system and process the samples according to § 86.140, obtaining a stabilized reading of the exhaust bag sample on all analyzers within 20 minutes of the end of the sample collection phase of the test. Obtain methanol and formaldehyde sample analyses, if applicable, within 24 hours of the end of the sample period. If it is not possible to perform analysis on the methanol and formaldehyde samples within 24 hours, the samples should be stored in a dark, cold (4-10 °C) environment until analysis. Analyze the samples within fourteen days.
(21) As soon as possible, and in no case longer than one hour after the end of the hot start phase of the test, transfer the six particulate filters to the weighing chamber for post-test conditioning, if applicable.
(22) Disconnect the exhaust tube from the vehicle tailpipe(s) and drive the vehicle from dynamometer.
(23) The CVS or CFV may be turned off, if desired.
(24) This completes the test sequence for vehicles that do not need testing for evaporative emissions. Continue testing for evaporative emissions as follows:
(i) For the three-day diurnal test sequence, proceed according to § 86.134.
(ii) For the two-day diurnal test sequence, proceed according to § 86.138-96(k). The following additional provisions apply for heavy-duty vehicles:
(A) For vehicles with a nominal fuel tank capacity at or above 50 gallons, operate the vehicle over a second full FTP cycle before measuring evaporative emissions; exhaust emission measurement is not required for the additional FTP cycle.
(B) [Reserved]
§ 86.138-96   Hot soak test.
(a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following the running loss test. However, sampling of emissions from the running loss test is not required as preparation for the hot soak test.
(2) Gaseous-fueled vehicles. Since gaseous-fueled vehicles are not required to perform a running loss test, the hot soak test shall be conducted within seven minutes after completion of the hot start exhaust test.
(b) The hot soak test may be conducted in the running loss enclosure as a continuation of that test or in a separate enclosure.
(1) If the hot soak test is conducted in the running loss enclosure, the driver may exit the enclosure after the running loss test. If exiting, the driver should use the personnel door described in § 86.107-96(a)(2), exiting as quickly as possible with a minimum disturbance to the system. The final hydrocarbon and methanol concentration for the running loss test, measured in § 86.134-96(g)(1)(xx), shall be the initial hydrocarbon and methanol concentration (time = 0 minutes) C HCi and C CH 3 OHi , for the hot soak test.
(2) If the vehicle must be moved to a different enclosure, the following steps must be taken:
(i) The enclosure for the hot soak test shall be purged for several minutes prior to completion of the running loss test. WARNING: If at any time the concentration of hydrocarbons, of methanol, or of methanol and hydrocarbons exceeds 15,000 ppm C the enclosure should be immediately purged. This concentration provides at least a 4:1 safety factor against the lean flammability limit.
(ii) The FID hydrocarbon analyzer shall be zeroed and spanned immediately prior to the test.
(iii) Fresh impingers shall be installed in the methanol sample collection system immediately prior to the start of the test, if applicable.
(iv) If not already on, the mixing fan(s) shall be turned on at this time. Throughout the hot soak test, the mixing fan(s) shall circulate the air at a rate of 0.8±0.2 cfm per cubic foot of the nominal enclosure volume.
(v) Begin sampling as follows:
(A) Analyze the enclosure atmosphere for hydrocarbons and record. This is the initial (time = 0 minutes) hydrocarbon concentration, C HCi , required in § 86.143. Hydrocarbon emissions may be sampled continuously during the test period.
(B) Analyze the enclosure atmosphere for methanol, if applicable, and record. The methanol sampling must start simultaneously with the initiation of the hydrocarbon analysis and continue for 4.0±0.5 minutes. This is the initial (time = 0 minutes) methanol concentration, C CH 3 OHi , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses.
(vi) The vehicle engine compartment cover shall be closed (if not already closed), the cooling fan shall be moved, the vehicle shall be disconnected from the dynamometer and any sampling system, and then driven at minimum throttle to the enclosure for the hot soak test. These steps should be done as quickly as possible to minimize the time needed to start the hot soak test.
(vii) The vehicle's engine must be stopped before any part of the vehicle enters the enclosure.
(viii) The vehicle shall enter the enclosure; the enclosure doors shall be closed and sealed within 2 minutes of engine shutdown and within seven minutes after the end of the running loss test.
(ix) The test vehicle windows and any luggage compartments shall be opened (if not already open). The vehicle engine compartment cover shall be closed (if not already closed).
(c) [Reserved]
(d) The temperature recording system shall be started and the time of engine shutoff shall be noted on the evaporative emission hydrocarbon data recording system.
(e) For the first 5 minutes of the hot soak test, the ambient temperature shall be maintained at 95±10 °F. For the remainder of the hot soak test, the ambient temperature shall be maintained at 95±5 °F (95±2 °F on average).
(f) The 60±0.5 minute hot soak begins when the enclosure doors are sealed (or when the running loss test ends, if the hot soak test is conducted in the running loss enclosure).
(g) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately prior to the end of the test.
(h) Fresh impingers shall be installed in the methanol collection system immediately prior to the end of the test, if applicable.
(i) [Reserved]
(j) At the end of the 60±0.5 minute test period:
(1) Analyze the enclosure atmosphere for hydrocarbons and record. This is the final (time = 60 minutes) hydrocarbon concentration, C HCf , required in § 86.143.
(2) Analyze the enclosure atmosphere for methanol and record, if applicable. The methanol sampling must start simultaneously with the initiation of the hydrocarbon analysis and continue for 4.0±0.5 minutes. This is the final (time = 60 minutes) methanol concentration, C CH 3 OHf , required in § 86.143. Record the time elapsed during this analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to allow accurate GC analysis, rapidly collect the methanol sample in a bag and then bubble the bag sample through the impingers at the specified flow rate. The time elapsed between collection of the bag sample and flow through the impingers should be minimized to prevent any losses.
(k) For the supplemental two-diurnal test sequence ( see § 86.130-96), perform a hot soak test as described in this section, except that the test shall be conducted within seven minutes after completion of the hot start exhaust test and temperatures throughout the hot soak measurement period must be between 68 ° and 86 °F. This hot soak test is followed by two consecutive diurnal heat builds, described in § 86.133-96(p).
(l) If the vehicle is to be tested for diurnal emissions, follow the procedure outlined in § 86.133-96.
§ 86.139-90   Particulate filter handling and weighing.
(a) At least 8 hours, but not more than 56 hours before the test, place each filter in an open, but protected, petri dish and place in the weighing chamber which meets the humidity and temperature specifications of § 86.112.
(b) At the end of the 8 to 56 hour stabilization period, weigh the filter on a balance having a precision of one microgram. Record this weight. This reading is the tare weight.
(c) The filter shall then be stored in a covered petri dish which shall remain in the weighing chamber until needed for testing.
(d)(1) If the filter is not used within one hour of its removal from the weighing chamber, it shall be reweighed.
(2) The one hour limit may be replaced by an eight-hour limit if one or both of the following conditions are met:
(i) A stabilized filter is placed and kept in a sealed filter holder assembly with the ends plugged, or
(ii) A stabilized filter is placed in a sealed filter holder assembly, which is then immediately placed in a sample line through which there is no flow.
(e) After the test, and after the sample filter is returned to the weighing room, condition it for at least 1 hour but not more than 56 hours. Then weigh a second time. This latter reading is the gross weight of the filter. Record this weight.
(f) The net weight (P e ) is the gross weight minus the tare weight.
Should the sample on the filter contact the petri dish or any other surface, the test is void and must be rerun.
§ 86.140-94   Exhaust sample analysis.
The following sequence shall be performed in conjunction with each series of measurements:
(a) For CO, CO 2 , CH 4 , NO X , and for Otto-cycle and methanol-fueled, natural gas-fueled and liquefied petroleum gas-fueled (if non-heated FID option is used) diesel vehicle HC:
(1) Zero the analyzers and obtain a stable zero reading. Recheck after tests.
(2) Introduce span gases and set instrument gains. In order to avoid errors, span and calibrate at the same flow rates used to analyze the test sample. Span gases should have concentrations equal to 75 to 100 percent of full scale. If gain has shifted significantly on the analyzers, check the calibrations. Show actual concentrations on chart.
(3) Check zeroes; repeat the procedure in paragraphs (a) (1) and (2) of this section if required.
(4) Check flow rates and pressures.
(5) Measure THC, CO, CO 2 , CH 4 , and NO X concentrations of samples.
(6) Check zero and span points. If difference is greater than 2 percent of full scale, repeat the procedure in paragraphs (a) (1) through (5) of this section.
(b) For petroleum-fueled, natural gas-fueled and liquefied petroleum gas-fueled (if HFID is used) diesel vehicle HC:
(1) Zero HFID analyzer and obtain a stable zero reading.
(2) Introduce span gas and set instrument gains. Span gas should have concentration equal to 75 to 100 percent of full scale.
(3) Check zero as in paragraph (b)(1) of this section.
(4) Introduction of zero and span gas into the analyzer can be accomplished by either of the following methods:
(i) Close heated valve in THC sample (see Figures B94-5 or B94-6) and allow gases to enter HFID. Extreme care should be taken not to introduce gases under high pressure.
(ii) Connect zero and span line directly to THC sample probe and introduce gases at a flow rate greater than 125 percent of the HFID flow rate with the CVS blower operating (see Figures B94-5 or B94-6). Excess flow must be allowed to exit probe inlet.
In order to minimize errors, HFID flow rate and pressure during zero and span (and background bag reading) must be exactly the same as that used during testing.
(5) Continuously record (integrate electronically if desired) dilute THC emission levels during test. Background samples are collected in sample bags and analyzed as in paragraphs (b)(4) (i) or (ii) of this section.
(6) Check zero and span as in paragraphs (b) (1) through (4) of this section. If difference is greater than 2 percent of full scale, void test and check for THC “hangup” or electronic drift in analyzer.
(c) For CH 3 OH (methanol-fueled vehicles), introduce test samples into the gas chromatograph and measure the concentration. This concentration is C MS in the calculations.
(d) For HCHO (methanol-fueled vehicles), introduce formaldehyde test samples into the high pressure liquid chromatograph and measure the concentration of formaldehyde as a dinitrophenylhydrazine derivative in acetonitrile. This concentration is C FS in the calculations.
(e) For CH 4 analysis:
(1) In the event that the procedure results in negative NMHC wm values (as may occur with high methane fractions), any negative NMHC wm value whose absolute value is less than 10 percent of the NMHC standard shall be rounded to zero. Negative NMHC wm values whose absolute value is more than 10 percent of the NMHC standard shall require sample remeasurement. If the 10 percent criterion cannot be met after remeasurement, the test will be void.
(2) Other sampling procedures may be used if shown to yield equivalent or superior results and if approved in advance by the Administrator.
§ 86.142-90   Records required.
The following information shall be recorded with respect to each test:
(a) Test number.
(b) System or device tested (brief description).
(c) Date and time of day for each part of the test schedule.
(d) Test results. Also include a comparison of drive cycle energy and target cycle energy relative to both inertia and road load forces as specified in 40 CFR 1066.425 for each drive cycle or test phase, as appropriate.
(e) Driver and equipment operator IDs.
(f) Vehicle. ID number, manufacturer, model year, standards, engine family, evaporative emissions family, basic engine description (including displacement, number of cylinders, turbo-/supercharger used, and catalyst usage), fuel system (including number of carburetors, number of carburetor barrels, fuel injection type, and fuel tank(s) capacity and location), engine code, gross vehicle weight rating, inertia weight class, actual curb weight at zero miles, actual road load at 50 mph (80 kph), transmission configuration, axle ratio, car line, system miles, idle rpm, and drive wheel tire pressure, as applicable.
(g) Dynamometer. Dynamometer ID, inertia weight setting, indicated power absorption setting, records to verify compliance with the vehicle speed versus time requirements of the test, and driving distance for each of the three phases of the test, calculated from the measured roll or shaft revolutions.
(h) Gas analyzers. Analyzer bench ID, analyzer ranges, recordings of analyzer output during zero, span, and sample readings.
(i) Recorder charts: Test number, date, vehicle ID, operator ID, and identification of the measurements recorded.
(j) Test cell barometric pressure, ambient temperature, and humidity.
A central laboratory barometer may be used: Provided, that individual test cell barometric pressures are shown to be within ±0.1 percent of the barometric pressure at the central barometer location.
(k) Temperatures. Records to verify compliance with the ambient temperature requirements throughout the test procedure and recordings of vehicle fuel temperature(s) during the diurnal test and of the enclosure temperatures during the diurnal and hot soak tests.
(l) CFV-CVS. Total dilute exhaust volume (Vmix) for each phase of the exhaust test.
(m) PDP-CVS. Test measurements required to calculate the Vmix. Total dilute exhaust volume (Vmix) for each phase of the exhaust test.
(n) The humidity of the dilution air.
If conditioning columns are not used (see §§ 86.122 and 86.144) this measurement can be deleted. If the conditioning columns are used and the dilution air is taken from the test cell, the ambient humidity can be used for this measurement.
(o) Additional records required for diesel vehicles. (1) Pressure and temperature of the dilute exhaust mixture (and background air if sampled) at the inlet to the gas meter used for particulate sampling.
(2) The temperature of the dilute exhaust mixture inside the dilution tunnel near the inlet of the particulate probe.
(3) The temperature of the gas flowing in the heated sample line before the heated filter, and also before the HFID, and the temperature of the control system of the heated hydrocarbon detector.
(4) Gas meter or flow measurement instrumentation readings at the start of each sample period and at the end of each sample period.
(5) The stabilized pre-test weight and post-test weight of each particulate sample and back-up filter.
(6) Continuous temperature and humidity recording of the ambient air in which the particulate filters were stabilized.
(p) Additional required records for methanol-fueled vehicles. (1) Specification of the methanol-fuel or methanol-fuel mixtures used during the test.
(2) Volume of sample passed through the methanol sampling system and the volume of deionized water in each impinger.
(3) The concentration of the GC analyses of the test samples (methanol).
(4) Volume of sample passed through the formaldehyde sampling system and the volume of DNPH solution used.
(5) The concentration of the HPLC analysis of the test sample (formaldehyde).
(6) The temperatures of the sample lines before the HFID and the impinger, the temperature of the exhaust transfer duct (as applicable), and the temperature of the control system of the heated hydrocarbon detector.
(7) A continuous measurement of the dew point of the raw and diluted exhaust. This requirement may be omitted if the temperatures of all heated lines are kept above 220 °F, or if the manufacturer performs an engineering analysis demonstrating that the temperature of the heated systems remains above the maximum dew point of the gas stream throughout the course of the test.
(q) Additional required records for natural gas-fueled vehicles. Composition, including all carbon containing compounds; e.g. CO 2 , of the natural gas-fuel used during the test. C 1 and C 2 compounds shall be individually reported. C 3 and heavier hydrocarbons, and C 6 and heavier compounds may be reported as a group.
(r) Additional required records for liquefied petroleum gas-fueled vehicles. Composition of the liquefied petroleum gas-fuel used during the test. Each hydrocarbon compound present, through C 4 compounds, shall be individually reported. C 5 and heavier hydrocarbons may be reported as a group.
§ 86.143-96   Calculations; evaporative emissions.
(a) The following equations are used to calculate the evaporative emissions from gasoline- and methanol-fueled vehicles, and for gaseous-fueled vehicles.
(b) Use the measurements of initial and final concentrations to determine the mass of hydrocarbons and methanol emitted. For testing with pure gasoline, methanol emissions are assumed to be zero.
(1) For enclosure testing of diurnal, hot soak, and running loss emissions:
(i) Methanol emissions:
(ii) Hydrocarbon emissions:
(iii) For variable-volume enclosures, defined in § 86.107(a)(1)(i), the following simplified form of the hydrocarbon mass change equation may be used:
(2) For running loss testing by the point-source method, the mass emissions of each test phase are calculated below, then summed for a total mass emission for the running loss test. If emissions are continuously sampled, the following equations can be used in integral form.
(i) Methanol emissions:
(ii) Hydrocarbon emissions:
(c) If the test fuel contains at least 25% oxygenated compounds by volume, measure the concentration of oxygenated compounds directly using a photoacoustic analyzer specified in 40 CFR 1065.269 or using impingers as described in 40 CFR 1065.805(f). Calculate total hydrocarbon equivalent emissions with the following equation, using density values specified in 40 CFR 1066.1005(f):
(d)(1) For the full three-diurnal test sequence, there are two final results to report:
(i) The sum of the adjusted total mass emissions for the diurnal and hot soak tests (M DI + M HS ); and
(ii) The adjusted total mass emissions for the running loss test, on a grams per mile basis = M RL /D RL , where D RL = miles driven for the running loss test (see § 86.134-96(c)(6)).
(2) For the supplemental two-diurnal test sequence, there is one final result to report: the sum of the adjusted total mass emissions for the diurnal and hot soak tests (M DI + M HS ), described in §§ 86.133-96(p) and 86.138-96(k), respectively.
§ 86.144-94   Calculations; exhaust emissions.
The final reported test results shall be computed by use of the following formula:
(a) For light-duty vehicles and light duty trucks:
(1) Y WM = Weighted mass emissions of each pollutant, i.e., THC, CO, THCE, NMHC, NMHCE, CH 4 , NO X , or CO 2 , in grams per vehicle mile.
(2) Y ct = Mass emissions as calculated from the “transient” phase of the cold start test, in grams per test phase.
(3) Y ht = Mass emissions as calculated from the “transient” phase of the hot start test, in grams per test phase.
(4) Y s = Mass emissions as calculated from the “stabilized” phase of the cold start test, in grams per test phase.
(5) D ct = The measured driving distance from the “transient” phase of the cold start test, in miles.
(6) D ht = The measured distance from the “transient” phase of the hot start test, in miles.
(7) D s = The measured driving distance from the “stabilized” phase of the cold start test, in miles.
(b) The mass of each pollutant for each phase of both the cold start test and the hot start test is determined from the following:
(1) Total hydrocarbon mass:
(2) Oxides of nitrogen mass:
(3) Carbon monoxide mass:
(4) Carbon dioxide mass:
(5) Methanol mass:
(6) Formaldehyde mass:
(7) Total hydrocarbon equivalent mass:
(8) Non-methane hydrocarbon mass:
(9) Non-methane hydrocarbon equivalent mass:
(10) Methane mass:
(11) Nitrous Oxide Mass:
(c) Meaning of symbols:
(1)(i) HC mass = Total hydrocarbon emissions, in grams per test phase.
(ii) Density HC = Density of total hydrocarbon.
(A) For gasoline-fuel, diesel-fuel and methanol fuel; Density HC = 16.33 g/ft 3 −carbon atom (0.5768 kg/m 3 −carbon atom), assuming an average carbon to hydrogen ratio of 1:1.85, at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(B) For natural gas and liquefied petroleum gas-fuel; Density HC = 1.1771 (12.011 + H/C (1.008)) g/ft 3 −carbon atom (0.04157(12.011 + H/C (1.008))kg/m 3 −carbon atom), where H/C is the hydrogen to carbon ratio of the hydrocarbon components of the test fuel, at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) HC conc = Total hydrocarbon concentration of the dilute exhaust sample corrected for background, in ppm carbon equivalent, i.e., equivalent propane × 3.
(B) HC conc = HC e −HC d (1−1/DF).
(iv)(A) HC e = Total hydrocarbon concentration of the dilute exhaust sample or, for diesel-cycle (or methanol-fueled vehicles, if selected), average hydrocarbon concentration of the dilute exhaust sample as calculated from the integrated THC traces, in ppm carbon equivalent.
(B) HC e = FID HC e −(r)C CH 3 OHe.
(v) FID HC e = Concentration of total hydrocarbon plus methanol in dilute exhaust as measured by the FID, ppm carbon equivalent.
(vi) r = FID response to methanol.
(vii) C CH 3 OHe = Concentration of methanol in dilute exhaust as determined from the dilute exhaust methanol sample in ppm carbon. For vehicles not fueled with methanol, C CH 3 OHe equals zero.
(viii)(A) HC d = Total hydrocarbon concentration of the dilution air as measured, in ppm carbon equivalent.
(B) HC d = FID HC d −(r)C CH 3 OHd.
(ix) FID HC d = Concentration of total hydrocarbon plus methanol in dilution air as measured by the FID, ppm carbon equivalent.
(x) C CH 3 OHd = Concentration of methanol in dilution air as determined from dilution air methanol sample in ppm carbon. For vehicles not fueled with methanol, C CH 3 OHd equals zero.
(2)(i) NOx mass = Oxides of nitrogen emissions, in grams per test phase.
(ii) Density NO2 = Density of oxides of nitrogen is 54.16 g/ft3 (1.913 kg/m 3 ) assuming they are in the form of nitrogen dioxide, at 68 °F (20 °C) and 760 mm Hg (101.3kPa) pressure.
(iii)(A) NOx conc = Oxides of nitrogen concentration of the dilute exhaust sample corrected for background, in ppm.
(B) NOx conc = NOx e −NOx d (1−(1/DF)).
(iv) NOx e = Oxides of nitrogen concentration of the dilute exhaust sample as measured, in ppm.
(v) NOx d = Oxides of nitrogen concentration of the dilution air as measured, in ppm.
(3)(i) CO mass = Carbon monoxide emissions, in grams per test phase.
(ii) Density CO = Density of carbon monoxide is 32.97 g/ft 3 (1.164 kg/m3), at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) CO conc = Carbon monoxide concentration of the dilute exhaust sample corrected for background, water vapor, and CO 2 extraction, in ppm.
(B) CO conc = CO e − CO d (1 − (1/DF)).
(iv)(A) CO e = Carbon monoxide concentration of the dilute exhaust volume corrected for water vapor and carbon dioxide extraction, in ppm.
(B) CO e = (1 − 0.01925CO 2e -0.000323R)CO em for petroleum fuel with hydrogen to carbon ratio of 1.85:1.
(C) CO e = [1−(0.01 + 0.005HCR) CO 2e −0.000323R]CO em for methanol-fuel or natural gas-fuel or liquefied petroleum gas-fuel, where HCR is hydrogen-to-carbon ratio as measured for the fuel used.
(v) CO em = Carbon monoxide concentration of the dilute exhaust sample as measured, in ppm.
(vi) CO 2e = Carbon dioxide concentration of the dilute exhaust sample, in percent.
(vii) R = Relative humidity of the dilution air, in percent (see § 86.142(n)).
(viii)(A) CO d = Carbon monoxide concentration of the dilution air corrected for water vapor extraction, in ppm.
(B) CO d = (1-0.000323R)CO dm .
(ix) CO dm = Carbon monoxide concentration of the dilution air sample as measured, in ppm.
If a CO instrument which meets the criteria specified in § 86.111 is used and the conditioning column has been deleted, CO em must be substituted directly for CO e and CO dm must be substituted directly for CO d .
(4)(i) CO 2mass = Carbon dioxide emissions, in grams per test phase.
(ii) Density CO 2 = Density of carbon dioxide is 51.81 g/ft 3 (1.830 kg/m 3 ), at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) CO 2conc = Carbon dioxide concentration of the dilute exhaust sample corrected for background, in percent.
(B) CO 2conc = CO 2e − CO 2d (1 − (1/DF)). Where:
(iv) CO 2d = Carbon dioxide concentration of the dilution air as measured, in percent.
(5)(i) CH 3 OH mass = Methanol emissions corrected for background, in grams per test phase.
(ii) Density CH3OH = Density of methanol is 37.71 g/ft 3 -carbon atom (1.332 kg/m 3 -carbon atom), at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) CH 3 OH conc = Methanol concentration of the dilute exhaust corrected for background, ppm.
(B) CH 3 OH conc = C CH3OHe − C CH3OHd (1 − (1/DF)).
(iv)(A) C CH3OHe = Methanol concentration in the dilute exhaust, ppm.
(B)
(v)(A) C CH3OHd = Methanol concentration in the dilution air, ppm.
(B)
(vi) T EM = Temperature of methanol sample withdrawn from dilute exhaust, °R.
(vii) T DM = Temperature of methanol sample withdrawn from dilution air, °R.
(viii) P B = Barometric pressure during test, mm Hg.
(ix) V EM = Volume of methanol sample withdrawn from dilute exhaust, ft 3 .
(x) V DM = Volume of methanol sample withdrawn from dilution air, ft 3 .
(xi) C S = GC concentration of sample drawn from dilute exhaust, µg/ml.
(xii) C D = GC concentration of sample drawn from dilution air, µg/ml.
(xiii) AVS = Volume of absorbing reagent (deionized water) in impinger through which methanol sample from dilute exhaust is drawn, ml.
(xiv) AVD = Volume of absorbing reagent (deionized water) in impinger through which methanol sample from dilution air is drawn, ml.
(xv) 1 = first impinger.
(xvi) 2 = second impinger.
(xvii) 1 = first impinger.
(xviii) 2 = second impinger.
(6)(i) HCHO mass = Formaldehyde emissions corrected for background, in grams per test phase.
(ii) Density HCHO = Density of formaldehyde is 35.36 g/ft 3 - carbon atom (1.249 kg/m 3 -carbon atom), at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) HCHO conc = Formaldehyde concentration of the dilute exhaust corrected for background, in ppm.
(B) HCHO conc = C HCHOe − C HCHOd (1 − (1/DF)).
(iv)(A) C HCHOe = Formaldehyde concentration in dilute exhaust, in ppm.
(B)
(v)(A) C HCHOd = Formaldehyde concentration in dilution air in ppm.
(B)
(vi) C FDE = Concentration of DNPH derivative of formaldehyde from dilute exhaust sample in sampling solution, µg/ml.
(vii) V AE = Volume of sampling solution for dilute exhaust formaldehyde sample, ml.
(viii)(A) Q = Ratio of molecular weights of formaldehyde to its DNPH derivative.
(B) Q = 0.1429.
(ix) T EF = Temperature of formaldehyde sample withdrawn from dilute exhaust, °R.
(x) V SE = Volume of formaldehyde sample withdrawn from dilute exhaust, ft 3 .
(xi) P B = Barometric pressure during test, mm Hg.
(xii) C FDA = Concentration of DNPH derivative of formaldehyde from dilution air sample in sampling solution, µg/ml.
(xiii) V AA = Volume of sampling solution for dilution air formaldehyde sample, ml.
(xiv) T DF = Temperature of formaldehyde sample withdrawn from dilution air, °R.
(xv) V SA = Volume of formaldehyde sample withdrawn from dilution air, ft 3 .
(7)(i) DF = 13.4/[CO 2e + (HC e + CO e ) 10 −4 ] for petroleum-fueled vehicles.
(ii) For methanol-fueled vehicles, where fuel composition is C X H y O z as measured, or calculated, for the fuel used:
(iii)
(iv)(A) K H = Humidity correction factor.
(B) K H = 1/[1−0.0047(H−75)].
(C) For SI units, K H = 1 × [1-0.0329(H × 10.71)].
(v)(A) H = Absolute humidity in grains (grams) of water per pound (kilogram) of dry air.
(B) H=[(43.478)R a × P d ]/[P B −(P d × R a /100)].
(C) For SI units, H=[(6.211)R a × P d ]/[P B × (P d × R a /100)].
(vi) R a = Relative humidity of the ambient air, percent.
(vii) P d = Saturated vapor pressure, mm Hg (kPa) at the ambient dry bulb temperature.
(viii) P B = Barometric pressure, mm Hg (kPa).
(ix)(A) V mix = Total dilute exhaust volume in cubic feet per test phase corrected to standard conditions (528°R (293 °K) and 760 mm Hg (101.3 kPa)).
(B) For PDP-CVS, V mix is:
(C) For SI units,
(x) V o = Volume of gas pumped by the positive displacement pump, in cubic feet (m 3 ) per revolution. This volume is dependent on the pressure differential across the positive displacement pump.
(xi) N = Number of revolutions of the positive displacement pump during the test phase while samples are being collected.
(xii) P B = Barometric pressure, mm Hg (kPa).
(xiii) P 4 = Pressure depression below atmospheric measured at the inlet to the positive displacement pump, in mm Hg (kPa) (during an idle mode).
(xiv) T p = Average temperature of dilute exhaust entering positive displacement pump during test, °R(°K).
(8)(i) NMHC conc = HC conc − (r CH4 × CH 4conc ).
(ii) Density NMHC = The density of non-methane hydrocarbon.
(A) For gasoline-fuel and diesel-fuel; Density NMHC = 16.33 g/ft 3 -carbon atom (0.5768 kg/m 3 -carbon atom), assuming an average carbon to hydrogen ratio of 1:1.85 at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(B) For natural gas and liquefied petroleum gas fuel; Density NMHC = 1.1771(12.011 + H/C(1.008))g/ft 3 -carbon atom (0.04157(12.011 + H/C(1.008))kg/m 3 -carbon atom), where H/C is the hydrogen to carbon ratio of the non-methane hydrocarbon components of the test fuel, at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(iii)(A) CH 4conc = Methane concentration of the dilute exhaust sample corrected for background, in ppm carbon equivalent.
(B) CH 4conc = CH 4e − CH 4d (1 − 1/DF)
(iv) CH 4e = Methane exhaust bag concentration in ppm carbon equivalent.
(v) CH 4d = Methane concentration of the dilution air in ppm carbon equivalent.
(vi) rCH4 = HC FID response to methane as measured in § 86.121(d).
(9)(i) CH 4mass = Methane emissions, in grams per test phase.
(ii) Density CH4 = Density of methane is 18.89 g/ft 3 -carbon atom (0.6672 kg/m 3 -carbon atom), at 68 °F (20 °C) and 760 mm Hg (101.3 kPa) pressure.
(10)(i) N 2 O mass = Nitrous oxide emissions, in grams per test phase.
(ii) Density N2O = Density of nitrous oxide is 51.81 g/ft 3 (1.83 kg/m 3 ), at 68 °F (20 °C) and 760 mm Hg (101.3kPa) pressure.
(iii)(A) N 2 O conc = Nitrous oxide concentration of the dilute exhaust sample corrected for background, in ppm.
(B) N 2 O conc = N 2 O e − N 2 O d (1 − (1/DF)).
(d) For petroleum-fueled vehicles, example calculation of mass values of exhaust emissions using positive displacement pump:
(1) For the “transient” phase of the cold start test assume the following: V o = 0.29344 ft 3 rev; N = 10,485; R = 48.0 pct; R a = 48.2 percent; P B = 762 mm Hg; P d = 22.225 mm Hg; P 4 = 70 mm Hg; T p = 570 °R; HC e = 105.8 ppm, carbon equivalent; NOx e = 11.2 ppm; CO em = 306.6 ppm; CO 2e = 1.43 percent; CH 4e = 10.74 ppm; HC d = 12.1 ppm; NOx d = 0.8 ppm; CO dm = 15.3 ppm; CO 2d = 0.032 percent; CH 4d = 2.20 ppm; D ct = 3.598 miles.
(i) V mix = (0.29344)(10,485)(762-70)(528)/(760)(570) = 2595.0 ft 3 per test phase.
(ii) H = (43.478)(48.2)(22.225)/762 − (22.225)(48.2/100) = 62 grains of water per pound of dry air.
(iii) K H = 1/[1 − 0.0047(62-75)] = 0.9424.
(iv) CO e = [1-0.01925(1.43) − 0.000323(48)](306.6) = 293.4 ppm.
(v) CO d = [1 − 0.000323(48)](15.3) = 15.1 ppm.
(vi) DF = 13.4/[1.43 + 10 −4 (105.8 + 293.4)] = 9.116.
(vii) HC conc = 105.8-12.1(1 − 1/9.116) = 95.03 ppm.
(viii) HC mass = (2595)(16.33)(95.03/1,000,000) = 4.027 grams per test phase.
(ix) NOx conc = 11.2 − 0.8(1 − 1/9.116) = 10.49 ppm.
(x) NOx mass = (2595)(54.16)(10.49/1,000,000)(0.9424) = 1.389 grams per test phase.
(xi) CO conc = 293.4 − 15.1(1 − 1/9.116) = 280.0 ppm.
(xii) CO mass = (2595)(32.97)(280/1,000,000) = 23.96 grams per test phase.
(xiii) CO 2conc = 1.43 − 0.032(1 − 1/9.116) = 1.402 percent.
(xiv) CO 2mass = (2595.0)(51.85)(1.402/100) = 1886 grams per test phase.
(xv) CH 4conc = 10.74 − 2.2 (1 − 1/9.116) = 8.78 ppm.
(xvi) NMHC conc = 95.03 − 8.78 = 86.25 ppm.
(xvii) NMHC mass = (2595)(16.33)(86.25)/1,000,000 = 3.655 grams per test phase.
(2) For the stabilized portion of the cold start test assume that similar calculations resulted in the following:
(i) HC mass = 0.62 gram per test phase.
(ii) NOx mass = 1.27 grams per test phase.
(iii) CO mass = 5.98 grams per test phase.
(iv) CO 2mass = 2346 grams per test phase.
(v) D s = 3.902 miles.
(vi) NMHC mass = 0.50 gram per test phase.
(3) For the “transient” portion of the hot start test assume that similar calculations resulted in the following:
(i) HC mass = 0.51 gram per test phase.
(ii) NOx mass = 1.38 grams per test phase.
(iii) CO mass = 5.01 grams per test phase.
(iv) CO 2mass = 1758 grams per test phase.
(v) D ht = 3.598 miles.
(vi) NMHC mass = 0.44 grams per test phase.
(4) Weighted mass emission results:
(i) HC wm = 0.43[(4.027 + 0.62)/(3.598 + 3.902)] + 0.57[(0.51 + 0.62)/(3.598 + 3.902)] = 0.352 gram per vehicle mile.
(ii) NOx wm = 0.43[(1.389 + 1.27)/(3.598 + 3.902)] + 0.57[(1.38 + 1.27)/(3.598 + 3.902)] = 0.354 gram per vehicle mile.
(iii) CO wm = 0.43[(23.96 + 5.98)/(3.598 + 3.902)] + 0.57[(5.01 + 5.98)/(3.598 + 3.902)] = 2.55 grams per vehicle mile.
(iv) CO 2wm = 0.43[(1886 + 2346)/(3.598 + 3.902) + 0.57[(1758 + 2346)/(3.598 + 3.902)] = 555 gram per vehicle mile.
(v) NMHC wm = 0.43[(3.655 + 0.50)/(3.598 + 3.902)] + 0.57[(0.44 + 0.50)/(3.598 + 3.902)] = 0.310 gram per vehicle mile.
(e) For methanol-fueled vehicles with measured fuel composition of CH 3.487 O 0.763 , example calculation of exhaust emissions using positive displacement pump:
(1) For the “transient” phase of the cold start test assume the following: V 0 = 0.29344 ft 3 rev; N = 25,801; R = 37.5 pct; Ra = 37.5 percent; P B = 725.42 mm Hg; P d = 22.02 mm Hg; P 4 = 70 mm Hg; T p 570 deg.R; FID HC e = 14.65 ppm, carbon equivalent; r = 0.788; T EM = 527.67 deg.R; V EM = 0.2818 ft 3 ; C S1 = 7.101; AV S1 = 15.0 ml; C S2 = 0.256; AV S2 = 15.0 ml; T DM = 527.67 deg.R; V DM = 1.1389 ft 3 ; C D1 = 0.439; AV D1 = 15.0 ml; C D2 = 0.0; AV D2 = 15.0 ml; C FDE = 8.970 µg/ml; V AE = 5.0 ml; Q = 0.1429; T EF = 527.67 deg.R; V SE = 0.2857 ft 3 ; C FDA = 0.39 µg/ml; V AA = 5.0 ml; T DF = 527.67 deg.R; V SA = 1.1043 ft 3 ; NO X . = 5.273 ppm; CO em = 98.8 ppm; CO 2e = 0.469 pct; CH 4e = 2.825 ppm; FID HC d = 2.771 ppm; NO X . = 0.146 ppm; CO dm = 1.195 ppm; CO 2d = 0.039 percent; CH 4d = 2.019 ppm; Dct = 3.583 miles.
(i) V mix = (0.29344)(25,801)(725.42-70)(528)/(760)(570) = 6048.1.0 ft 3 per test phase.
(ii) H = (43.478)(37.5)(22.02)/[725.42-(22.02 × 37.5/100)] = 50 grains of water per pound of dry air.
(iii) K H = 1/[1−0.0047(50−75)] = 0.8951.
(iv) CO e = [1-(0.01 + 0.005 × 3.487) × 0.469)−0.000323(37.5)) × 98.8 = 96.332 ppm.
(v) CO d = (1−0.000323(37.5)) × 1.195 = 1.181 ppm.
(vi) C CH3OHe = (3.813 × 10 −2 )(527.67)[(7.101)(15.0) + (0.256)(15.0)]/(725.42)(0.2818) = 10.86 ppm.
(vii) HCe = 14.65−(0.788)(10.86) = 6.092.
(viii) DF = 100(1/[1 + (3.487/2) + 3.76(1 + (3.487/4) − (0.763/2))])/0.469 + (6.092 + 96.332 + 10.86 + 0.664)(10 −4 ) = 24.939.
(ix) C CH3OHd = (3.813 × 10 −2 )(527.67)[(0.439)(15.0) + (0.0)(15.0)]/(725.42)(1.1389) = 0.16 ppm.
(x) CH 3 OH conc = 10.86−0.16(1-1/24.939) = 10.71 ppm.
(xi) CH 3 OH mass = 6048.1 × 37.71 × (10.71/1,000,000) = 2.44 grams per test phase.
(xii) HC conc = [14.65 − (0.788)(10.86)] − [2.771 − (0.788)(0.16)] (1-1/24.94) = 3.553 ppm.
(xiii) HC mass = (6048.1)(16.33)(3.553/1,000,000) = 0.35 grams per test phase.
(xiv) C HCHOe = 4.069 × 10 −2 (8.970)(5.0)(0.1429)(527.67)/(0.2857)(725.42) = 0.664 ppm.
(xv) C HCHOd = 4.069 × 10 −2 (0.39)(5.0)(0.1429)(527.67)/(1.1043)(725.42) = 0.0075 ppm.
(xvi) HCHO conc = 0.664-0.0075(1-1/24.939) = 0.6568 ppm.
(xvii) HCHO mass = (6048.1)(35.36)(0.6568/1,000,000) = 0.1405 grams per test phase.
(xviii) THCE = 0.35 + (13.8756/32.042)(2.44) + (13.8756/ 30.0262)(0.1405) = 1.47 grams per test phase.
(xix) NO Xconc = 5.273−(0.146)(1-1/24.939) = 5.13 ppm.
(xx) NO Xmass = (6048.1)(54.16)(5.13/1,000,000)(0.8951) = 1.505 grams per test phase.
(xxi) CO conc = 96.332−1.181(1-1/24.939) = 95.2 ppm.
(xxii) CO mass = (6048.1)(32.97)(95.2/1,000,000) = 18.98 grams per test phase.
(xxiii) CO2 conc = 0.469-0.039(1-1/24.939) = 0.432 percent.
(xxiv) CO2 mass = (6048.1)(51.85)(0.432/100) = 1353 grams.
(xxv) CH4 conc = 2.825-2.019(1-1/24.939) = 0.89 ppm.
(xxvi) NMHC conc = 3.553 ppm−0.89 ppm = 2.67 ppm.
(xxvii) NMHC mass = (6048.1)(16.33)(2.67/1,000,000) = 0.263 grams per test phase.
(xxviii) NMHCE mass = 0.263 + (13.8756/32.042)(2.44) + (13.8756/ 30.0262)(0.1405) = 1.39 grams per test phase.
(2) For the stabilized portion of the cold start test assume that similar calculations resulted in the following:
(i) THCE = 0.143 grams per test phase.
(ii) NO Xmass = 0.979 grams per test phase.
(iii) CO mass = 0.365 grams per test phase.
(iv) CO 2mass = 1467 grams per test phase.
(v) D s = 3.854 miles.
(vi) NMHCE = 0.113 grams per test phase.
(3) For the “transient” portion of the hot start test assume that similar calculations resulted in the following:
(i) THCE = 0.488 grams as carbon equivalent per test phase.
(ii) NO Xmass = 1.505 grams per test phase.
(iii) CO mass = 3.696 grams per test phase.
(iv) CO 2mass = 1179 grams per test phase.
(v) D ht = 3.577 miles.
(vi) NMHCE = 0.426 grams per test phase.
(4) Weighted emission results:
(i) THCE wm = (0.43) × (1.473 + 0.143)/(3.583 + 3.854) + (0.57) × (0.488 + 0.143)/(3.577 + 3.854) = 0.142 grams as carbon equivalent per mile.
(ii) NOx wm = (0.43) × (1.505 + 0.979)/(3.583 + 3.854) + (0.57) × (1.505 + 0.979)/3.577 + 3.854) = 0.344 grams per mile.
(iii) CO wm = (0.43) × (18.983 + 0.365)/(3.583 = 3.854) + (0.57) × (3.696 + 0.365)/(3.577 + 3.854) = 1.43 grams per mile.
(iv) CO2 wm = (0.43) × (1353 + 1467)/(3.583 + 3.854) + (0.57) × (1179 + 1467)/(3.577 + 3.854) = 366 grams per mile.
(v) NMHCE wm = (0.43) × (1.386 + 0.113)/(3.583 + 3.854) + (0.57) × (0.426 = 0.113)/(3.577 + 3.854) = 0.128 grams per mile.
§ 86.145-82   Calculations; particulate emissions.
(a) The final reported test results for the mass particulate (M p ) in grams/mile shall be computed as follows.
(1) M p1 = Mass of particulate determined from the “transient” phase of the cold start test, in grams per test phase. (See § 86.110-82(c)(1) for determination.)
(2) M p2 = Mass of particulate determined from the “stabilized” phase of the cold start test, in grams per test phase. (See § 86.110-82(c)(1) for determination.)
(3) M p3 = Mass of particulate determined from the “transient” phase of the hot start test, in grams per test phase. (See § 86.110-82(c)(1) for determination).
(4) D ct = The measured driving distance from the “transient” phase of the cold start test, in miles.
(5) D s = The measured driving distance from the “stabilized” phase of the cold start test, in miles.
(6) D ht = The measured driving distance from the “transient” phase of the hot start test, in miles.
(b) The mass of particulate for each phase of testing is determined as follows:
(1) j = 1, 2 or 3 depending on which phase the mass of particulate is being determined for (i.e., the “transient” phase of the cold start test, the “stabilized” phase of the cold start test, or the “transient” phase of the hot start test).
(2) V mix = Total dilute exhaust volume in cubic meters per test, corrected to standard conditions 528°R (293K) and 29.92 in Hg (101.3 kPa). V mix is further defined in § 86.144.
(3) P e = mass of particulate per test on the exhaust filter(s), grams.
(4) P b = mass of particulate on the “background” filter, grams.
(i) The background particulate level, P b , inside the dilution air filter box at EPA is very low. P b will be assumed = 0, and background particulate samples will not be taken with each exhaust sample. It is recommended that background particulate checks be made periodically to verify the low level.
(ii) Any manufacturer may make the same assumption without prior EPA approval.
(iii) If P b is assumed = 0, then no background correction is made. The equation for particulate mass emissions then reduces to:
(6) V ep = total volume of sample pulled through the filter, cubic feet at standard conditions.
(i) V ap = corrected (according to procedure specified in § 85.120) dilute exhaust sample volume, cubic feet.
(ii) P bar = barometric pressure, in Hg.
(iii) P ip = pressure elevation above ambient measured at the inlet to the dilute exhaust sample gas meter or flow instrument, in Hg. (For most gas meters with unrestricted discharge P ip is negligible and can be assumed = 0.)
(iv) T ip = average temperature of the dilute exhaust sample at the inlet to the gas meter or flow instrument, °R.
(7) V bp = total volume of the background sample, cubic feet at standard conditions. (V bp is not required if P b is assumed = 0.) It is calculated using the following formula:
(i) V ab = corrected (according to procedure specified in § 85.120) background sample volume, cubic feet.
(ii) P bar = barometric pressure, in. Hg.
(iii) P ib = pressure elevation above ambient measured at the inlet to the background gas meter or flow instrument, in Hg. (For most gas meters with unrestricted discharge P ib is negligible and can be assumed = 0.)
(iv) T ib = average temperature of the background sample at the inlet to the gas meter or flow instrument, °R.
(8) DF = dilution factor. (DF is not required if P b is assumed = 0.)
§ 86.146-96   Fuel dispensing spitback procedure.
(a) The vehicle is fueled at a rate of 10 gal/min to test for fuel spitback emissions. All liquid fuel spitback emissions that occur during the test are collected in a bag made of a material impermeable to hydrocarbons or methanol. The bag shall be designed and used so that liquid fuel does not spit back onto the vehicle body, adjacent floor, etc., and it must not impede the free flow of displaced gasoline vapor from the orifice of the filler pipe. The bag must be designed to permit passage of the dispensing nozzle through the bag. If the bag has been used for previous testing, sufficient time shall be allowed for the bag to dry out. The dispensing nozzle shall be a commercial model, not equipped with vapor recovery hardware.
(b) Ambient temperature levels encountered by the test vehicle shall be not less than 68 °F nor more than 86 °F. The temperatures monitored during testing must be representative of those experienced by the test vehicle. The vehicle shall be approximately level during all phases of the test sequence to prevent abnormal fuel distribution.
(c) Measure and record the mass of the bag to be used for collecting spitback emissions to the nearest 0.01 gram.
(d) Drain the fuel tank(s) and fill with test fuel, as specified in § 86.113, to 10 percent of the reported nominal fuel tank capacity. The fuel cap(s) shall be installed immediately after refueling.
(e) The vehicle shall be soaked at 80±6 °F (27±3 °C) for a minimum of six hours, then placed, either by being driven or pushed, on a dynamometer and operated through one Urban Dynamometer Driving Schedule (specified in § 86.115 and appendix I of this part). The test vehicle may not be used to set dynamometer horsepower.
(f) Following the preconditioning drive, the vehicle shall be moved or driven at minimum throttle to the refueling area.
(g) All areas in proximity to the vehicle fuel fill orifice and the dispenser nozzle itself shall be completely dry of liquid fuel.
(h) The fuel filler neck shall be snugly fitted with the vented bag to capture any fuel emissions. The fuel nozzle shall be inserted through the bag into the filler neck of the test vehicle to its maximum penetration. The plane of the nozzle's handle shall be perpendicular to the floor of the laboratory.
(i) The fueling procedure consists of dispensing fuel through a nozzle, interrupted by a series of automatic shutoffs. A minimum of 3 seconds shall elapse between any automatic shutoff and subsequent resumption of dispensing. Dispensing may not be manually terminated, unless the test vehicle has already clearly failed the test. The vehicle shall be fueled according to the following procedure:
(1) The fueling operation shall be started within 4 minutes after the vehicle is turned off and within 8 minutes after completion of the preconditioning drive. The average temperature of the dispensed fuel shall be 65 ±5 °F (18 ±3 °C).
(2) The fuel shall be dispensed at a rate of 9.8±0.3 gallons/minute (37.1±1.1 L/min) until the automatic shutoff is activated.
(3) If the automatic shutoff is activated before the nozzle has dispensed an amount of fuel equal to 70 percent of the tank's nominal capacity, the dispensing may be resumed at a reduced rate. Repeat as necessary until the nozzle has dispensed an amount of fuel equal to at least 70 percent of the tank's nominal capacity.
(4) Once the automatic shutoff is activated after the nozzle has dispensed an amount of fuel equal to 70 percent of the tank's nominal capacity, the fuel shall be dispensed at a rate of 5 ±1 gallons/minute (19 ±4 ℓ/min) for all subsequent dispensing. Dispensing shall be restarted two additional times.
(5) If the nozzle has dispensed an amount of fuel less than 85 percent of the tank's nominal capacity after the two additional dispensing restarts, dispensing shall be resumed, and shall continue through as many automatic shutoffs as necessary to achieve this level. This completes the fueling procedure.
(j) Withdraw the nozzle from the vehicle and the bag, holding the tip of the nozzle upward to avoid any dripping into the bag.
(k) Within 1 minute after completion of the fueling event, the bag shall be folded to minimize the vapor volume inside the bag. The bag shall be folded as quickly as possible to prevent evaporation of collected emissions.
(l) Within 5 minutes after completion of the fueling event, the mass of the bag and its contents shall be measured and recorded (consistent with paragraph (c) of this section). The bag shall be weighed as quickly as possible to prevent evaporation of collected emissions.
§ 86.150-98   Refueling test procedure; overview.
(a) The refueling emissions test procedure described in this and subsequent sections is used to determine the conformity of vehicles with the refueling emissions standards set forth in subpart A of this part for light-duty vehicles and light-duty trucks. The refueling emissions test procedure may be performed as an individual test or in combination with the evaporative and exhaust emissions test sequences of § 86.130-96.
(b) The refueling emissions test is designed to measure hydrocarbon emissions resulting from the generation or displacement of fuel tank vapor during vehicle refueling. The refueling emissions shall be measured by the enclosure technique.
(c) All emission control systems installed on or incorporated in a new motor vehicle shall be functioning during all procedures in this subpart except:
(1) In cases of component malfunction or failure; and
(2) during certain specified fuel drain and fill operations, at which times the refueling emission control canister is disconnected. Maintenance to correct component malfunction or failure shall be authorized in accordance with § 86.098-25.
(d) For liquefied petroleum gas-fueled vehicles only. Refueling test procedures for light-duty vehicles and light-duty trucks operated on liquefied petroleum gas are described in § 86.157.
§ 86.151-98   General requirements; refueling test.
(a) The refueling emissions procedure, shown in Figure B98-12, starts with the stabilizing of the vehicle and the loading of the refueling emissions canister(s) to breakthrough, and continues with the vehicle drive for purging of the canister, followed by the refueling emissions measurement. The test is conducted following §§ 86.152-98 through 86.154-98 in order.
(b) Ambient temperature levels encountered by the test vehicle throughout the test sequence shall not be less than 68 °F (20 °C) nor more than 86 °F (30 °C).
(c) The vehicle shall be approximately level during all phases of the test sequence to prevent abnormal fuel distribution.
§ 86.152-98   Vehicle preparation; refueling test.
(a) Provide additional fittings and adapters, as required, to accommodate a fuel drain at the lowest point possible in the tank(s) as installed on the vehicle. The canister shall not be removed from the vehicle, unless access to the canister in its normal location is so restricted that purging and loading can only reasonably be accomplished by removing the canister from the vehicle. Special care shall be taken during this step to avoid damage to the components and the integrity of the fuel system. A replacement canister may be temporarily installed during the soak period while the canister from the test vehicle is preconditioned.
(b) Optionally, provide valving or other means to allow the venting of the refueling vapor line to the atmosphere rather than to the refueling emissions canister(s) when allowed by this test procedure.
(c) For preconditioning that involves loading the vapor collection canister(s) with butane, provide valving or other means as necessary to allow loading of the canister(s).