United States Environmental Protection Agency Air and Radiation E P A420-R-00-007 April 2000


# IM240 & E v ap T echnical Guidance

Printed on Recycled Paper

### EPA420-R-00-007 April 2000



# IM240 & Evap Technical Guidance

Transportation and Regional Programs Division Office of Transportation and Air Quality U.S. Environmental Protection Agency

NOTICE This technical report does not necessarily represent final EPA decisions or positions. It is intended to present technical analysis of issues using data which are currently available. The purpose in the release of such reports is to facilitate the exchange of technical information and to inform the public of technical developments which may form the basis for a final EPA decision, position, or regulatory action.Introduction
§85.2205 Test Standards ......................................................................................................... ......... 1 (a) IM240 Emission Standards .............................................................................................. 1 (b) Transient Test Score Calculations .................................................................................... 5 (c) Evaporative System Pressure Test Standards ................................................................. 10 (d) Gas Cap Test Standards .................................................................................................. 10
§85.2221 IM240 Test Procedures .................................................................................................. 12 (a) General Requirements .................................................................................................... 12 (b) Pre-inspection and Preparation ....................................................................................... 12 (c) Equipment Positioning and Settings ............................................................................... 13 (d) Vehicle Conditioning ...................................................................................................... 14 (e) Vehicle Emission Test Sequence .................................................................................... 15 (f) Emission Measurements ................................................................................................. 18
§85.2222 Evaporative System Pressure and Gas Cap Test Procedures ......................................... 19 (a) General Requirements .................................................................................................... 19 (b) Pre-inspection and Preparation ....................................................................................... 19 (c) Fuel Inlet Pressure Test .................................................................................................. 19 (d) Gas Cap Test ................................................................................................................ .. 20
§85.2226 IM240 Equipment Specifications ................................................................................... 21 (a) Dynamometer Specifications .......................................................................................... 21 (b) Constant Volume Sampler .............................................................................................. 25 (c) Analytical Instruments .................................................................................................... 27
§85.2227 Evaporative System Equipment Specifications .............................................................. 29 (a) General Requirements .................................................................................................... 29 (b) Evaporative System Pressure Test Equipment ............................................................... 29 (c) Gas Cap Test Equipment ................................................................................................ 29
§85.2234 IM240 Test Quality Control Requirements .................................................................... 31 (a) General Requirements .................................................................................................... 31 (b) Dynamometer ................................................................................................................. 31 (c) Constant Volume Sampler .............................................................................................. 33 (d) Analysis System ............................................................................................................. 34 (e) Gases ....................................................................................................................... ....... 36 (f) Overall System Performance .......................................................................................... 37 (g) Control Charts .............................................................................................................. .. 37
§85.2235 Evaporative Test Quality Control Requirements ............................................................ 39 (a) General Requirements .................................................................................................... 39 (b) Evaporative Pressure Checks ......................................................................................... 39 (c) Evaporative Gas Cap Checks ......................................................................................... 39
§85.2239 Test Report ............................................................................................................ ......... 40 (a) General Test Report Information .................................................................................... 40(b) Tests and Results ........................................................................................................... . 40 (c) Recommended IM240 Second-By-Second Emissions Report ....................................... 41
§85.2241 Terms .................................................................................................................. ............ 43
Appendix A Guidance on the Use of Fast-Pass IM240 Standards .................................................................... 44
Appendix B Alternative Fast-Pass IM240 Standards ........................................................................................ 50
Appendix C Fast Pass IM240 Standards Developed for Wisconsin ................................................................. 66
Appendix D Fast Pass IM240 Standards: Modal Regression Technique .......................................................... 73
Appendix E Calculation of Raw Emission Scores from Dilute Measurements ................................................ 82
Appendix F Modal Analysis of Second-by-Second Data Preconditioning Guidelines ................................... 87
Appendix G Full and Fast-Pass IM240 Positive Kinetic Energy Speed Variation Limits ................................ 91
Appendix H Derivation of TRLHP Coefficients ............................................................................................. 10 0
Appendix I Derivation of TRLHP Coefficients ............................................................................................ 10 3Introduction
This document is the successor to the August 1998 version of the EPA “IM240 & Evap Technical Guidance” and incorporates changes made since its publication. The following changes have been incorporated in this release of the EPA I/M technical guidance:
1) All references to the EPA evaporative emission purge test have been removed. Standards, procedures, specifications, and quality control practices are described in the August 1998 technical guidance.
2) A spreadsheet and example for usage of the Modal Fast Pass concept have been posted with the IM240 & Evap Technical Guidance on the EPA I/M web site..
3) K1 and K2 coefficients have been changed in 85.2205(b)(3)(iv)(E) to make them technically correct.
4) The exponent in the humidity correction factor in 85.2205(b)(3)(xi)(F) has been corrected for a typographical
error. 5) References to procedures for treatment of OBD II evaporative emission controlled vehicles have been revised to state that guidance for these vehicles will be published in a separate document, not a revision of the IM240 & Evap Technical Guidance.
6) The standard for the fuel inlet pressure test, 85.2205(d)(2)(i) has corrected a typographical error. The value “8" has been changed to “6.”
7) 85.2222(a)(2) has added a sentence stating fuel volatility is also a factor contributing to test variability when conducting the fuel inlet pressure test.
8) 85.2226(a)(3)(iii) has been revised to specify response time measurements at 2000, base inertia, and 5500 pounds of inertia.
9) 85.2227(b)(1)(i) has been added to specifically permit the use of flow based leak detection methods, but no standards have been proposed at present.
10) The text in 85.2227(c)(1)(iv) has been revised to clarify the term “automated.” The new wording states automatic operation means automated measurement of the pass/fail condition and a requirement for a real time data link.
11) Paragraphs (ii) and (iii) of 85.2234 have been modified to provide more flexible load settings at 50 and 20 mph to achieve longer and more measurable coast down times. The 22 to 18 mph coastdown limit has been changed to ± 6 seconds.
12) The 0.4% of point tolerance in 85.2234(d)(3) has been revised to ± 2% of point of a specific analyzer range, and the first sentence is modified to state its intent is to apply to the initial setting of a span point.
13) Paragraph 4 of 85.2234(g)(4) has been revised to state that driving trace quality is an example of how control charts for individual inspectors may used.
14) An equation has been added to 85.2239(b)(6) to define how “gpme” is calculated.15) Appendix I, Derivation of GTRL Coefficients has been revised to clarify its content, and make it more compatible with terms and equations provided by Sierra Research in the supporting documentation when the EPA I/M Look-up Table is revised.1 §85.2205 Test Standards

(a) IM240 Emission Standards
(1) Two Ways to Pass Standards . If the corrected, composite emission rates calculated in §85.2205(b) exceed the standards for any exhaust component, additional analysis of test results shall look at the second phase of the driving cycle separately. Phase 2 shall include second 94 through second 239. Second-by-second emission rates in grams, and composite emission rates in grams per mile for Phase 2 and for the entire test shall be recorded for each gas. If the composite emission level is equal to or below the composite standard, or if the Phase 2 grams per mile emission level is equal to or below the applicable Phase 2 standard, then the vehicle shall pass the test for that exhaust component.
(2) Start-up Standards . Start-up standards should be used during the first two years of program operation. Tier 1 standards are recommended for 1996 and newer vehicles and may be used for 1994 and newer vehicles certified to Tier 1 standards as well. The following exhaust emissions standards, in grams per mile, are recommended:
(i) Light Duty Vehicles

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1996+ 0.80 0.50 15.0 12.0 2.0 2.0 1991-1995 1.20 0.75 20.0 16.0 2.5 2.5 1983-1990 2.00 1.25 30.0 24.0 3.0 3.0 1981-1982 2.00 1.25 60.0 48.0 3.0 3.0 1980 2.00 1.25 60.0 48.0 6.0 6.0 1977-1979 7.50 5.00 90.0 72.0 6.0 6.0 1975-1976 7.50 5.00 90.0 72.0 9.0 9.0 1973-1974 10.0 6.00 150 120 9.0 9.0 1968-1972 10.0 6.00 150 120 10.0 10.0 (ii) High-Altitude Light Duty Vehicles

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1983-1984 2.00 1.25 60.0 48.0 3.0 3.0 1982 2.00 1.25 75.0 60.0 3.0 3.0 (iii) Light Duty Trucks (0 - 6000 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2 1996+

(< 3750 LVW) 0.80 0.50 15.0 12.0 2.0 2.0 (>3750 LVW) 1.00 0.63 20.0 16.0 2.5 2.5 1991-1995 2.40 1.50 60.0 48.0 3.0 3.0 1988-1990 3.20 2.00 80.0 64.0 3.5 3.5 1984-1987 3.20 2.00 80.0 64.0 7.0 7.0 1979-1983 7.50 5.00 100 80.0 7.0 7.01 The heavy-duty truck standards provided here were calculated using new vehicle certification standards and have not been subjected to field testing. This document provides no other guidance on heavy duty truck testing. Thus, anyone interested in performing IM240 tests on heavy-duty trucks should proceed with appropriate caution.

2 1975-1978 8.00 5.00 120 96.0 9.0 9.0 1973-1974 10.0 6.00 150 120 9.0 9.0 1968-1972 10.0 6.00 150 120 10.0 10.0 (iv) High-Altitude Light Duty Trucks (0 - 6000 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1991+ 3.00 2.00 70.0 56.0 3.0 3.0 1988-1990 4.00 2.50 90.0 72.0 3.5 3.5 1984-1987 4.00 2.50 90.0 72.0 7.0 7.0 1982-1983 8.00 5.00 130 104 7.0 7.0 (v) Light Duty Trucks (6001 - 8500 pounds GVWR)

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 CompositePhase 2 1996+

(< 5750 ALVW) 1.00 0.63 20.0 16.0 2.5 2.5 (>5750 ALVW) 2.40 1.50 60.0 48.0 4.0 4.0 1991-1995 2.40 1.50 60.0 48.0 4.5 4.5 1988-1990 3.20 2.00 80.0 64.0 5.0 5.0 1984-1987 3.20 2.00 80.0 64.0 7.0 7.0 1979-1983 7.50 5.00 100 80.0 7.0 7.0 1975-1978 8.00 5.00 120 96.0 9.0 9.0 1973-1974 10.0 6.00 150 120 9.0 9.0 1968-1972 10.0 6.00 150 120 10.0 10.0 (vi) High-Altitude Light Duty Trucks (6001 - 8500 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1991+ 3.00 2.00 70.0 56.0 4.5 4.5 1988-1990 4.00 2.50 90.0 72.0 5.0 5.0 1984-1987 4.00 2.50 90.0 72.0 7.0 7.0 1982-1983 8.00 5.00 130 104 7.0 7.0 (vii) Heavy-Duty Trucks (greater than 8500 pounds GVWR)

. 1

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1998+ 2.00 1.30 30.0 24.0 4.0 4.0 1991-1997 3.00 1.90 60.0 48.0 6.0 6.0 1987-1990 3.00 1.90 60.0 48.0 8.0 8.03 1985-1986 5.00 3.10 75.0 60.0 8.0 8.0 1979-1984 6.00 3.80 100.0 80.0 8.0 8.0 1974-1978 10.0 6.30 150.0 120.0 10.0 10.0 1970-1973 10.0 6.30 175.0 140.0 10.0 10.0 pre-1970 20.0 12.50 200.0 160.0 15.0 15.0 (3) Final Standards . The following exhaust emissions standards, in grams per mile, are recommended for vehicles tested in the calendar years 1997 and later. Tier 1 standards are recommended for all 1996 and newer vehicles but may be used for 1994 and newer vehicles.
(i) Light Duty Vehicles

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1996+ 0.60 0.40 10.0 8.0 1.5 1.5 1983-1995 0.80 0.50 15.0 12.0 2.0 2.0 1981-1982 0.80 0.50 30.0 24.0 2.0 2.0 1980 0.80 0.50 30.0 24.0 4.0 4.0 1977-1979 3.00 2.00 65.0 52.0 4.0 4.0 1975-1976 3.00 2.00 65.0 52.0 6.0 6.0 1973-1974 7.00 4.50 120 96.0 6.0 6.0 1968-1972 7.00 4.50 120 96.0 7.0 7.0 (ii) High-Altitude Light Duty Vehicles

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1983-1984 1.20 0.75 30.0 24.0 2.0 2.0 1982 1.20 0.75 45.0 36.0 2.0 2.0 (iii) Light Duty Trucks (0 - 6000 pounds GVWR)

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2 1996+

(< 3750 LVW) 0.60 0.40 10.0 8.0 1.5 1.5 (>3750 LVW) 0.80 0.50 13.0 10.0 1.8 1.8 1988-1995 1.60 1.00 40.0 32.0 2.5 2.5 1984-1987 1.60 1.00 40.0 32.0 4.5 4.5 1979-1983 3.40 2.00 70.0 56.0 4.5 4.5 1975-1978 4.00 2.50 80.0 64.0 6.0 6.0 1973-1974 7.00 4.50 120 96.0 6.0 6.0 1968-1972 7.00 4.50 120 96.0 7.0 7.0 (iv) High-Altitude Light Duty Trucks (0 - 6000 pounds GVWR)

. Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1988+ 2.00 1.25 60.0 48.0 2.5 2.5 1984-1987 2.00 1.25 60.0 48.0 4.5 4.54 1982-1983 4.00 2.50 90.0 72.0 4.5 4.5 (v) Light Duty Trucks (6001 - 8500 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2 1996+

(< 5750 ALVW) 0.80 0.50 13.0 10.0 1.8 1.8 (>5750 ALVW) 0.80 0.50 15.0 12.0 2.0 2.0 1988-1995 1.60 1.00 40.0 32.0 3.5 3.5 1984-1987 1.60 1.00 40.0 32.0 4.5 4.5 1979-1983 3.40 2.00 70.0 56.0 4.5 4.5 1975-1978 4.00 2.50 80.0 64.0 6.0 6.0 1973-1974 7.00 4.50 120 96.0 6.0 6.0 1968-1972 7.00 4.50 120 96.0 7.0 7.0 (vi) High-Altitude Light Duty Trucks (6001 - 8500 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1988+ 2.00 1.25 60.0 48.0 3.5 3.5 1984-1987 2.00 1.25 60.0 48.0 4.5 4.5 1982-1983 4.00 2.50 90.0 72.0 4.5 4.5 (vii) Heavy-Duty Trucks (greater than 8500 pounds GVWR)

.
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen Composite Phase 2 Composite Phase 2 Composite Phase 2

1998+ 2.00 1.30 30.0 24.0 4.0 4.0 1991-1997 2.00 1.30 40.0 32.0 5.0 5.0 1987-1990 2.00 1.30 40.0 32.0 6.0 6.0 1985-1986 3.00 1.90 50.0 40.0 6.0 6.0 1979-1984 5.00 3.10 75.0 60.0 6.0 6.0 1974-1978 10.0 6.30 150.0 120.0 10.0 10.0 1970-1973 10.0 6.30 175.0 140.0 10.0 10.0 pre-1970 20.0 12.50 200.0 160.0 15.0 15.0 (4) Fast-Pass . Vehicles may be fast-passed using the following algorithm.
(i) Fast-Pass Algorithm

. Beginning at second 30 of the driving cycle, cumulative secondby-second emission levels for each second, calculated from the start of the cycle in grams, shall be compared to the cumulative fast-pass emission standards for the second under consideration. For exhaust components subject to Phase 2 standards, cumulative second-by-second emission levels calculated in grams from second 109 forward shall be compared to cumulative second-by-second fast-pass Phase 2 emission standards for the second under consideration.
(ii) Fast-Pass Standards

. A vehicle shall pass the IM240 for a given exhaust component if either of the following conditions occur:5 (A) cumulative emissions of each exhaust are below the full cycle fast-pass standard for the second under consideration; or,
(B) at second 109 and later, (if the exhaust component is subject to Phase 2 standards) cumulative Phase 2 emissions of each exhaust component are below the Phase 2 fast-pass standards for the second under consideration;
(iii) Fast-Pass End of Test

. Testing may be terminated when fast-pass criteria are met for all subject exhaust components.
(iv) Applicability of Fast-Pass Standards

. If a fast-pass determination cannot be made for all subject exhaust components before the driving cycle ends, the pass/fail determination for each component shall be based on composite or Phase 2 emissions over the full driving cycle as described in §85.2205(a)(1).
(v) Fast-Pass Algorithms

. Vehicles may be fast-passed using other approaches if they are approved by the Administrator. States are encouraged to develop and use equations to define fast-pass standards for each composite emission standard rather than using tabular standards for each second of the test.
EPA-developed, tabular, fast-passed standards are included in Appendix A.
Fast-pass standards developed by Radian for Colorado are included in Appendix B.
Appendix C contains fast-pass standards generated by EPA for Wisconsin at the state's request. This was done to allow the state to move toward implementing final IM240 standards.
Appendix D contains fast-pass guidelines and 0.8 g/mi HC composite standards along with 0.5 g/mi HC Phase 2 cut points developed by Sierra Research under contract 68- C4-0056 Work Assignment 2-04. A complete listing of the modal regression coefficients would be too large to print in an appendix; however, the description in Appendix D is intended to provide background information and the rational behind this methodology. A complete series of coefficients are available on EPA's web site.

(b) Transient Test Score Calculations (1) Composite Scores . The composite scores for the test shall be determined by dividing the sum of the mass of each exhaust component obtained in each second of the test by the number of miles driven in the test. The first data point is the sample taken from t=0 to t=1. The composite test value shall be calculated by the equation in §85.2205(b)(1)(i):6 (i) Composite gpm = 

### emissions( g )

distance(m iles) s=0

s

s=0 s 

# ∑ ∑

Where: s = duration of test in seconds for fast pass = 239 seconds for complete IM240

(2) Second-by-Second Mass Calculations . The mass of each exhaust component shall be calculated to five significant digits for each second of the test using the following equations:

(i) Hydrocarbon mass: HC mass = V mix * Density HC * 

### H C 1,000,000 conc

(ii) Carbon Monoxide mass: CO mass = V mix * Density CO * 

### C O 1,000,000 conc

(iii) Oxides of Nitrogen mass: NOxmass = V mix * Density NO2 * K H * 

### N O 1,000,000 conc

(iv) Carbon Dioxide mass: CO2mass = V mix * Density CO2 * 

### CO2 100 conc

(3) Meaning of Terms

.
(i) V mix = The CVS flow rate in cubic feet per second corrected to standard temperature and pressure.7 (ii) HC mass = Hydrocarbon emissions in grams per second.
(iii) Density HC = Density of hydrocarbons is 16.33 grams per cubic foot assuming an average carbon to hydrogen ratio of 1:1.85 at 68°F and 760 mm Hg pressure. (iv) HC conc = Average hydrocarbon concentration per second of the dilute exhaust sample corrected for background, in ppm carbon equivalent, i.e., equivalent propane * 3.

(A) HC conc = HC e - HC d (1 - ) Where: 

### 1 D F
(B) HC e = Hydrocarbon concentration of the dilute exhaust sample, in ppm carbon equivalent.
(C) HC d = Background hydrocarbon concentration of the dilution air, in ppm carbon equivalent.

(D) DF = 

### 13.4 C O 2 (H C C O ) * 1 0 ee e 4



### + + −

This is calculated on a second-by-second basis, where CO 2 is measured in % and HC and CO are measured in ppm. Note this DF does not accountfor pollutants in the background air and becomes less accurate as the airfuel ratio of the vehicle deviates from stoichiometric.

(E) 

## ( ) () ( )( ) D F 100 K CO K CO K (HC ) K CO CO K CO CO K (HC HC ) alt 1 2d 2 d 3 d
1 2e 2d 2 e d 3 e d 

### = − −− − + −+ −

This method of calculating DF is also done on a second-by-second basis and accounts for pollutants in the background air as well as being more accurate than the method in (D) above when the vehicle deviates from stoichiometric operation. All concentrations are expressed in volume percent and the values of the constants for gasoline fuel are: K1 = 7.4806, K2 = 5.5936, and K3 = 57.0945. Appendix E contains additional information on this subject.
If raw emission scores are being determined from dilute measurements, EPA recommends the use of this method for calculating DF.
(v) CO mass = Carbon monoxide emissions in grams per second.
(vi) Density CO = Density of carbon monoxide is 32.97 grams per cubic foot at 68°F and 760 mm Hg pressure.8 (vii) CO conc = Average carbon monoxide concentration per second of the dilute exhaust sample, corrected for background, water vapor, and CO 2 extraction, in ppm.

(A) CO conc = CO e - CO d (1 - ) 

### 1 D F
(B) CO e = Carbon monoxide concentration of the dilute exhaust, in ppm.
(C) CO d = Background carbon monoxide concentration of the dilution air, in ppm. (viii) NO xmass = Oxides of nitrogen emissions in grams per second.
(ix) Density NO2 = Density of oxides of nitrogen is 54.16 grams per cubic foot assuming they are in the form of nitrogen dioxide at 68°F and 760 mm Hg pressure. (x) NO xconc = Average concentration of oxides of nitrogen per second of the dilute exhaust sample, corrected for background in ppm.

(A) NO xconc = NO xe - NO xd (1 - ) 

### 1 D F
(B) NO xe = Oxides of nitrogen concentration of the dilute exhaust sample, in ppm.
(C) NO xd = Background oxides of nitrogen concentration of the dilution air, in ppm.
(xi) K H = humidity correction factor
(A) Standard Method

K H = 

### 1.0 1.0 0.0047 * (H 75.0)

− − (B) H = Absolute humidity in grains of water per pound of dry air.

= 

### 43.478 * R * P P (P * R 100 ) a d

b d a



### −

(C) R a = Relative humidity of the ambient air, percent.2 This revised method for calculating K H as a function of both T and H is based on work performed by Sierra Research under contract 68-C4-0056, Work Assignment 2-04. If the calculated value of K H exceeds 2.19, the value of K H shall be set to 2.19. This analysis used the same MY69, 5-vehicle sample employed for the original K H factor study that resulted in the current CFR standard K H calculation method (listed in (xi)(A) above). However, in many cases IM testing occurs outside the temperature limits set by the CFR for the standard method; therefore, at this time EPA recommends using the revised method when testing above 86 ( F.

9 (D) P d = Saturated vapor pressure, mm Hg at the ambient dry bulb temperature.
(E) P b = Barometric pressure, mm Hg.

(F) Revised method 2

K H = 

## e [0.004977(H 75) .004447(T 75)]

−− −
(G) H = Absolute humidity in grains of water per pound of dry air.
(H) T = Temperature in °F.

NOTE: If the calculated K H using either method of calculation is greater than 2.19, the value of K H shall be set at 2.19.

(xiii) CO 2mass = Carbon dioxide emissions in grams per second.
(xiv) Density CO2 = Density of carbon dioxide is 51.81 grams per cubic foot at 68°F and 760 mm Hg.
(xv) CO 2conc = Average carbon dioxide concentration per second of the dilute exhaust sample, corrected for background, in percent.

(A) CO 2conc = CO 2e - CO 2d (1 - ) 

### 1 D F
(B) CO 2d = Background carbon dioxide concentration of the dilution air, in percent. (4) Negative Values . Negative gram per second readings shall be integrated as zero and recorded as such. Negative values measured for ambient background concentrations (HC d , CO d , CO 2d , and NO xd ) used in 85.2205(b)(3) shall be calculated as zero and recorded as such.
(5) Determination of Raw Exhaust Concentrations from IM240 Results . Although the IM240 is a mass-based test, it is possible to estimate tailpipe concentrations from the dilute measurements for those vehicles only required to undergo an idle test. One method for performing this10 calculation can be found in SAE manuscript 980678. Additional clarification on this can be found in Appendix E.
(c) Evaporative System Pressure Test Standards The methods described below are applicable to pre OBD II evaporative emission controlled vehicles. OBD II vehicles equipped with evaporative control monitors and certified to the enhanced evaporative emission standards are being phased-in with the 1996 through 1998 model years. Those vehicles must be tested using either OBD II scan tools, by measuring pressure loss through an evaporative emission "service port," or by following vehicle manufacturer specific instruction to avoid damaging rigid vapor lines which are prevalent on many vehicles equipped with enhanced evaporative emission control systems. Procedures for using OBD II scan tools will be published in a separate document.
All I/M programs conducting a pressure test must perform a leak check on the gas cap and provide a unique test result.
(1) Visual Check . The vehicle shall fail the evaporative system visual check if any part of the system is missing, damaged, improperly connected, or disconnected as described in §85.2222(b).
(2) Fuel Inlet Pressure Test

. (i) Pressure Test Method . A vehicle shall fail the pressure test if the fuel vapor control system isolated between the fuel inlet and a clamp on the line between the fuel tank and the canister, (located as close to the canister as possible) loses more than 6 inches of water pressure over a period of 120 seconds starting from a stabilized pressure of 14±1 inch of water.
(ii) Fast-Pass . Fast-pass determinations for the pressure test may be made anytime during the pressure decay between 20 and 120 seconds if the measured pressure exceeds:

P m = 

### P ( 0.33 * P 120 )*t i i



### − + 133

.

Where: P m = Measured pressure in inches of water

P i = Initial pressure in inches of water

t = Time in seconds
(d) Gas Cap Test Standards The methods described below are applicable to pre OBD II evaporative emission controlled vehicles. OBD II vehicles equipped with evaporative control monitors and certified to the enhanced evaporative emission standards are being phased-in with the 1996 through 1998 model years. Procedures for OBD vehicles will be published in a separate document.11 Pressure decay methods using a 1 liter head space are currently permitted under the June 1996 version of the IM240 technical guidance. As this method has been widely used in IM240 testing it will continue to be allowed. The pressure decay loss of 6 inches of WC from a starting pressure of 28 in. WC referenced to 70F and 1 atm and assuming a 1 liter head space, equates to a flow rate of about 80 cc/min.
(1) Visual Check . The vehicle shall fail the gas cap visual check if the cap is missing, obviously defective, or the wrong style cap for the vehicle. An example of a wrong style includes a cam lock cap installed on fill pipe which requires a threaded cap. States conducting cap testing should work with OEM suppliers to develop a user friendly method of identifying wrong style gas caps. (2) Pressure Decay Test Standard . For pressure decay methods using a 1 liter head space and the June 1996 IM240 technical guidance, the fuel cap shall fail the pressure test if it loses more than 6 inches of water column (WC) pressure over a period of 10 seconds from a starting pressure of 28±1 inch WC.
(3) 60 cc/min Flow Standard . The gas cap leak rate may be determined by pressure loss measurement, direct flow measurement, or flow comparison methods and shall be compared to a pass/fail flow rate standard of 60 cubic centimeters per minute of air at 30 inches of water column. The flow rate methods shall be referenced to standard conditions of 70 ( F and 1 atm. If the leak rate exceeds 60 cc/min at a pressure of 30 inches of water column, the cap shall fail the test.12 §85.2221 IM240 Test Procedures

(a) General Requirements
(1) Test Parameters . The following information shall be determined for the vehicle being tested and used to automatically select the dynamometer inertia, power absorption settings, and evaporative emission test parameters.
(i) Model Year (ii) Manufacturer (iii) Model name (iv) Body style (v) Number of cylinders (vi) Engine displacement
Alternative computerized methods of selecting dynamometer test conditions, such as VIN decoding, may be used.
(2) Ambient Conditions . The ambient temperature, absolute humidity, and barometric pressure shall be recorded continuously during the transient test, or as a single set of readings if taken less than 4 minutes prior to the transient driving cycle.
(3) Restart . If shut off, the vehicle shall be restarted as soon as possible before the test and shall be running at least 30 seconds prior to the transient driving cycle.
(b) Pre-inspection and Preparation
(1) Accessories . All accessories (air conditioning, heat, defogger, radio, automatic traction control if switchable, etc.) shall be turned off by the inspector, if necessary.
(2) Traction Control and Four-Wheel Drive (4WD). Vehicles with traction control systems that cannot be turned off shall not be tested on two wheel drive dynamometers. Vehicles with 4WD that cannot be turned off shall only be tested on 4WD dynamometers. If the 4WD function can be disabled, then 4WD vehicles may be tested on two wheel drive dynamometers.
(3) Leaks . The vehicle shall be inspected for exhaust leaks. Audio assessment while blocking exhaust flow, or measurement of carbon dioxide or other gases, shall be acceptable. Vehicles with leaking exhaust systems shall be rejected from testing.
(4) Operating Temperature . The vehicle temperature gauge, if equipped and operating, shall be checked to assess temperature. If the temperature gauge indicates that the engine is well below (less than 180 ( F) normal operating temperature, the vehicle shall not be fast-failed and shall get a second-chance emission test if it fails the initial test for any criteria exhaust component. Vehicles in overheated condition shall be rejected from testing.
(5) Tire Condition . Vehicles shall be rejected from testing if tire cords, bubbles, cuts, or other damage are visible. Vehicles shall be rejected that have space-saver spare tires, or unreasonably sized tires on the drive axle. Vehicle tires shall be visually checked for adequate pressure level. Drive wheel tires that appear low shall be inflated to approximately 30 psi, or to tire side wall13 pressure, or manufacturer's recommendation. The tires of vehicles being tested for the purposes of program evaluation under §51.353(c) shall have their tires inflated to tire side wall pressure.
(6) Ambient Background . Background concentrations of hydrocarbons, carbon monoxide, oxides of nitrogen, and carbon dioxide (HC, CO, NO x , and CO 2 , respectively) shall be sampled as specified in §85.2226(b)(2)(iv) to determine background concentration of dilution air. The sample shall be taken for a minimum of 15 seconds within 120 seconds of the start of the transient driving cycle, using the same analyzers used to measure tailpipe emissions except as provided in §85.2226(c)(4)(iv). Average readings over the 15 seconds for each gas shall be recorded in the test record. Testing shall be prevented until the average ambient background levels are less than 20 ppmC HC, 30 ppm CO, and 2 ppm NO x , or outside ambient air levels (not influenced by station exhaust), whichever are greater.
Other methods that do not employ a fixed analysis time of 15 seconds may be used, if approved by the Administrator.
(7) Sample System Purge . While a lane is in operation, the CVS shall continuously purge the CVS hose between tests. The blower may be turned off if the CVS is not in operation, but the system shall be purged for 2 minutes prior to the start of a test if the blower has been turned off. The off time shall be computer monitored and recorded to a history file for quality assurance.
(c) Equipment Positioning and Settings
(1) Roll Rotation . The vehicle shall be maneuvered onto the dynamometer with the drive wheels positioned on the dynamometer rolls. Prior to test initiation, the rolls shall be rotated until the vehicle laterally stabilizes on the dynamometer. Drive wheel tires shall be dried if necessary to prevent slippage during the initial acceleration.
(2) Cooling System . The use of a cooling system is optional when testing at temperatures below 50 ( F. Furthermore, the hood may be opened at the state's discretion. If a cooling system is in use, testing shall not begin until the cooling system is positioned and activated. The cooling system shall be positioned to direct air to the vehicle cooling system, but shall not be directed at the catalytic converter.
(3) Vehicle Restraint . Testing shall not begin until the vehicle is restrained. Any restraint system shall meet the requirements of §85.2226(a)(5)( vii ). The parking brake shall be set for front wheel drive vehicles prior to the start of the test. The parking brake need not be set for vehicles that release the parking brake automatically when the transmission is put in gear.
(4) Dynamometer Settings . Dynamometer power absorption and inertia weight settings shall be automatically chosen from an EPA-supplied electronic look-up table which will be referenced based upon the vehicle identification information obtained in 85.2221(a)(1). Vehicles not listed shall be tested using default power absorption and inertia settings in the latest version of the EPA I/M Look-up Table, as posted on EPA's web site: www.epa.gov/orcdizux/im.htm
(5) Exhaust Collection System . The exhaust collection system shall be positioned to insure complete capture of the entire exhaust stream from the tailpipe during the transient driving cycle. The system shall meet the requirements of §85.2226(b)(2).14 (d) Vehicle Conditioning (1) Queuing Time . When the vehicle queue exceeds 20 minutes, a vehicle shall get a secondchance emission test if it fails the initial test and all criteria exhaust components are at or below 1.5 times the standard. At the state’s discretion, second-chance testing may be granted if criteria exhaust components exceed any preset level above the standard.
(2) Program Evaluation . Vehicles being tested for the purpose of program evaluation under §51.353(c) shall receive two full transient emission tests (i.e., a full 240 seconds each). Results from both tests and the test order shall be separately recorded in the test record. Emission scores and results provided to the motorist may be from either test.
(3) Discretionary Preconditioning

. (i) Any vehicle may be preconditioned by maneuvering the vehicle on to the dynamometer and driving the 94 to 239 second segment of the transient cycle in 85.2221(e)(1). This method has been demonstrated to adequately precondition the vast majority of vehicles (SAE 962091).
Other preconditioning cycles may be developed and used if approved by the Administrator.
(ii) Alternatively, modal analysis of the failing second-by-second test data may be performed to identify vehicles that would benefit from additional pre-conditioning. Appendix F provides retest criteria developed by Sierra Research under EPA contract 68-C4-0056 Work Assignment 2-04.15 (e) Vehicle Emission Test Sequence
(1) Transient Driving Cycle . The vehicle shall be driven over the following cycle:

Time second Speed mph Time second Speed mph Time second Speed mph Time second Speed mph Time second Speed mph 0 0 48 25.7 96 0 144 24.6 192 54.6 1 0 49 26.1 97 0 145 24.6 193 54.8 2 0 50 26.7 98 3.3 146 25.1 194 55.1 3 0 51 27.5 99 6.6 147 25.6 195 55.5 4 0 52 28.6 100 9.9 148 25.7 196 55.7 5 3 53 29.3 101 13.2 149 25.4 197 56.1 6 5.9 54 29.8 102 16.5 150 24.9 198 56.3 7 8.6 55 30.1 103 19.8 151 25 199 56.6 8 11.5 56 30.4 104 22.2 152 25.4 200 56.7 9 14.3 57 30.7 105 24.3 153 26 201 56.7 10 16.9 58 30.7 106 25.8 154 26 202 56.3 11 17.3 59 30.5 107 26.4 155 25.7 203 56 12 18.1 60 30.4 108 25.7 156 26.1 204 55 13 20.7 61 30.3 109 25.1 157 26.7 205 53.4 14 21.7 62 30.4 110 24.7 158 27.3 206 51.6 15 22.4 63 30.8 111 25.2 159 30.5 207 51.8 16 22.5 64 30.4 112 25.4 160 33.5 208 52.1 17 22.1 65 29.9 113 27.2 161 36.2 209 52.5 18 21.5 66 29.5 114 26.5 162 37.3 210 53 19 20.9 67 29.8 115 24 163 39.3 211 53.5 20 20.4 68 30.3 116 22.7 164 40.5 212 54 21 19.8 69 30.7 117 19.4 165 42.1 213 54.9 22 17 70 30.9 118 17.7 166 43.5 214 55.4 23 14.9 71 31 119 17.2 167 45.1 215 55.6 24 14.9 72 30.9 120 18.1 168 46 216 56 25 15.2 73 30.4 121 18.6 169 46.8 217 56 26 15.5 74 29.8 122 20 170 47.5 218 55.8 27 16 75 29.9 123 20.7 171 47.5 219 55.2 28 17.1 76 30.2 124 21.7 172 47.3 220 54.5 29 19.1 77 30.7 125 22.4 173 47.2 221 53.6 30 21.1 78 31.2 126 22.5 174 47.2 222 52.5 31 22.7 79 31.8 127 22.1 175 47.4 223 51.5 32 22.9 80 32.2 128 21.5 176 47.9 224 50.5 33 22.7 81 32.4 129 20.9 177 48.5 225 48 34 22.6 82 32.2 130 20.4 178 49.1 226 44.5 35 21.3 83 31.7 131 19.8 179 49.5 227 41 36 19 84 28.6 132 17 180 50 228 37.5 37 17.1 85 25.1 133 17.1 181 50.6 229 34 38 15.8 86 21.6 134 15.8 182 51 230 30.5 39 15.8 87 18.1 135 15.8 183 51.5 231 27 40 17.7 88 14.6 136 17.7 184 52.2 232 23.5 41 19.8 89 11.1 137 19.8 185 53.2 233 20 42 21.6 90 7.6 138 21.6 186 54.1 234 16.516 43 23.2 91 4.1 139 22.2 187 54.6 235 13 44 24.2 92 0.6 140 24.5 188 54.9 236 9.5 45 24.6 93 0 141 24.7 189 55 237 6 46 24.9 94 0 142 24.8 190 54.9 238 2.5 47 25 95 0 143 24.7 191 54.6 239 0

(2) Driving Trace . The inspector shall follow an electronic, visual depiction of the time/speed relationship of the transient driving cycle, or trace. The visual depiction of the trace shall be of sufficient magnification and adequate detail to allow accurate tracking by the driver and shall permit the driver to anticipate upcoming speed changes. The trace shall also clearly indicate gear shifts as specified in §85.2221(e)(3).
(3) Shift Schedule . For vehicles with manual transmissions, inspectors shall shift gears according to the following shift schedule:
Shift Sequence (gear) Speed (miles per hour) Nominal Cycle Time (seconds) 1 - 2 15 9.3 2 - 3 25 47.0 De-clutch 15 87.9 1 - 2 15 101.6 2 - 3 25 105.5 3 - 2 17 119.0 2 - 3 25 145.8 3 - 4 40 163.6 4 - 5 45 167.0 5 - 6 50 180.0 De-clutch 15 234.5

Gear shifts shall occur at the points in the driving cycle where the specified speeds are obtained. For vehicles with fewer than six forward gears the same schedule shall be followed while disregarding shifts above the highest gear.
(4) Speed Excursion Limits . Speed excursion limits shall apply as follows:
(i) Upper Limit . The upper limit is 2 mph higher than the highest point on the trace within 1 second of the given time.
(ii) Lower Limit . The lower limit is 2 mph lower than the lowest point on the trace within 1 second of the given time.
(iii) Speed Variations . Speed variations greater than the tolerances (such as may occur during gear changes) are acceptable provided they occur for no more than 2 seconds on any occasion.
(iv) Underpowered Vehicles . Speeds lower than those prescribed during accelerations are acceptable provided the vehicle is operated at maximum available power during such accelerations until the vehicle speed is within the excursion limits. If the vehicle is underpowered and unable to adequately follow the trace, it may at the State’s discretion be rejected from testing or given an idle test.17 (v) Exceedances . Exceedances of the limits in §85.2221(5)(ii) through §85.2221(5)(iii) shall automatically result in a void test. The station manager can override the automatic void of a test if the manager determines that the conditions specified in §85.2221(e)(4)(iv) occurred.
(5) Speed Variation Limits

. (i) Limits . Based on work performed under contract 68-C4-0056, Work Assignment 2-04 the following Positive Kinetic Energy limits were developed by Sierra Research. These results are based on an analysis of 16,581 IM240 tests conducted in AZ.

(ii) PKE = 

## P P

d x t t 0

t

x 0 x =

= 

# ∑ ∫

where: PP t = V 2 t - V 2 (t-1) mi 2 /hr 2 for V t > V (t-1)

PP t = 0 for V t = V (t-1) x = distance (mi)
(iii) PKE Limits . Full Test PKE Limits:
Upper Limit 3456 mi/hr 2

Lower Limit 3082 mi/hr 2
NOTE: The test cycle shall be invalid for a pass/fail determination if the PKE value is below the lower limit for a passing vehicle or above the upper limit for a failing vehicle. PKE values alone should not be used to make an early pass/fail determination.
Test cycles with PKE values outside the lower and upper limits shall be valid for preconditioning provided that all other requirements are met.
(iv) Second-by-Second Limits . Second-by-Second PKE upper and lower limits are listed in Appendix G.
(6) Distance Criteria . The actual distance traveled for the transient driving shall be measured. If the absolute difference between the measured distance and the theoretical distance for the actual test exceeds 0.05 miles, the test shall be void.
(7) Vehicle Stalls . Vehicle stalls during the test shall void the test and result in a new test. More than 3 stalls shall result in rejecting the vehicle from testing.18 (8) Inertia Weight Selection . The inertia weight selected for the vehicle shall be verified as specified in §85.2226(a)(1)(i). For systems employing electrical inertia simulation, an algorithm identifying the actual inertia force applied during the transient driving cycle shall be used to determine proper inertia simulation.
(9) CVS Operation . The CVS operation shall be verified for each test for a CFV-type CVS by measuring either the absolute pressure difference across the venturi or measuring the blower vacuum behind the venturi for minimum levels needed to maintain choke flow for the venturi design. The operation of an SSV-type CVS shall be verified throughout the test by monitoring the difference in pressure between upstream and throat pressure. The minimum values shall be determined from system calibrations. Monitored pressure differences below the minimum values shall void the test.
(f) Emission Measurements
(1) Exhaust Measurement . The emission analysis system shall sample and record dilute exhaust HC, CO, CO 2 , and NO x during the transient driving cycle as described in §85.2226(c).19 §85.2222 Evaporative System Pressure and Gas Cap Test Procedures

(a) General Requirements
(1) Pressure Test . The on-vehicle pressure tests described in §85.2222(c) shall be performed after any tailpipe emission test. Vehicles receiving a pressure test specified in §85.2222(c) should also be given a gas cap leak test specified in §§85.2222(d).
(2) Controlling Test Variability . The pressure test shall be conducted in a manner that minimizes changes in temperature, since pressure measurements are affected by changes in the vapor space temperature. Volume compensation for the pressure test is not required, but the vapor space volume will affect the pressure decay measurement. Excessive fuel vapor pressure, although not controllable at the time of test, may affect the accuracy and repeatability of the result.
(3) Gas Cap Test Requirement . A gas cap test described in §85.2222(d) may be performed before or after the tailpipe emission test.
(4) Alternative Techniques . Alternative gas cap or pressure test procedures may be used if they are shown to be equivalent or better than those described below.
(b) Pre-inspection and Preparation (1) Visual Inspection - Canister . The evaporative canister(s) shall be visually checked to the degree practical. A missing or obviously damaged canister(s) shall fail the visual evaporative system check.
(2) Visual Inspection - System . The evaporative system hoses shall be visually inspected for the appearance of proper routing, connection, and condition, to the degree practical. If any evaporative system hose is misrouted, disconnected, or damaged, the vehicle shall fail the visual evaporative system check.
(3) Visual Inspection - Gas Cap . If the gas cap is missing, obviously defective, or the wrong style cap for the vehicle, the vehicle shall fail the visual inspection.
(c) Fuel Inlet Pressure Test
(1) Equipment Set-up . The vapor vent line(s) from the gas tank to the canister(s) shall be clamped off as close to the canister(s) as practical without damaging evaporative system hardware. Dual fuel tanks shall be checked individually if the complete vapor control system can not be accessed by pressurizing from the fill pipe interface of only one fuel tank. The proper adapter, as specified in §85.2227(c)(2)(i) shall be selected.
(2) Starting Pressure . The gas tank shall be pressurized to 14±1 inch of WC, or a vehicle specific pressure as identified in the I/M Look-up Table.
(3) Stability . Pressure stability shall be monitored for a period of 10 seconds prior to the start of the pressure decay measurement. One definition of stability is a loss of no more than 5 inches WC over a 10 second period when the initial pressure is 14±1 inch WC. If the loss of pressure in 10 seconds exceeds this value, two more attempts shall be made to reach stability. Failure to achieve stability likely indicates the presence of a large leak and therefore failure of the pressure test. Alternate definitions of stability may be proposed by the State and approved by the Administrator. Stability criteria for flow comparator or direct flow measurement methods do not apply.20 (4) Volume Compensation . Pressure decay measurements are affected by the vapor volume in the fuel tank. Volume-compensated pressure decay measurements are presently not required. By design, flow comparator or flow measurement methods do not require volume corrections. (5) Pressure Monitoring . Close the pressure source and measure the loss in pressure over a 120 second interval. Fast-pass determinations may be made using the equations in §85.2205(d)(2)(ii).
(6) Clamp Removal . Remove the clamp on the vapor line and carefully relieve pressure and remove the adapter used to supply pressure to the vapor space.
(d) Gas Cap Test
(1) Cap Installation . The fuel cap, or caps, shall be removed from the fuel inlet(s) and installed on a portable or bench test rig using the adapter appropriate for the gas cap as specified in §85.2227(d)(1)(ii).
(2) Leak Measurement . The gas cap leak rate shall be measured and compared against a 60 cc/min at 30 in. WC flow standard. Pressure decay measurement using instruments with a 1 liter head space shall be made from an initial pressure of 28 in. WC and be compared against a loss of 6 in. WC in 10 seconds.
(3) Cap Replacement . The fuel cap(s) shall be replaced on the fuel inlet and tightened appropriately.21 §85.2226 IM240 Equipment Specifications

(a) Dynamometer Specifications
(1) General Requirements

. (i) Capacity . The dynamometer structure (e.g., bearings, rollers, pit plates, etc.) shall accommodate all light-duty vehicles and light-duty trucks up to 8500 pounds GVWR.
(ii) Test Parameters . Road load horsepower and inertia simulation shall be automatically selected from the EPA I/M Look-up Table, or equivalent data base, based on the vehicle parameters in the test record.
(iii) Alternative Designs . Alternative dynamometer specifications, designs, and error checking methods may be used if the alternative provides proper dynamometer loading over the IM240 driving cycle.
(iv) Units . Specifications in this section are generally expressed in units of horsepower. System designs using equivalent units of force, English or SI, are permissible.
(v) Ambient Range . The dynamometer shall be designed to meet specifications at an ambient temperature range of 35 to 110°F, and at absolute humidity values representative of the IM240 testing location.
(2) Power Absorption

. (i) Power Absorber Design . The power absorber unit shall be an electric AC or DC motor/absorber design. Eddy current designs may be approved if proven equivalent to other designs in terms of inertia response time, total load, and emissions performance over an IM240 driving cycle.
(ii) Range

. (A) Mechanical Inertia Dynamometers . Dynamometers using clutchable flywheels shall have sufficient power absorber capacity to accommodate the TRLHP values in the EPA I/M Look-up Table.
(B) Electric Inertia Dynamometers . Dynamometers using a combination of mechanical base inertia and supplemental electrical inertia shall have sufficient power absorber capacity to accommodate the sum of the TRLHP values in the EPA I/M Look-up Table plus the power absorbed from accelerating a vehicle at 3.3 mph/sec at the equivalent test weight (ETW) specified in the I/M Look-up Table.
(iii) Accuracy . The power absorber shall be adjustable across the required horsepower range at 50 mph in 0.1 horsepower increments. The accuracy of the power absorber or power exchange unit, for road load simulation only, shall be ±0.25 horsepower or ±3% of point, whichever is greater.
(iv) Indicated Horsepower . At constant velocity, the power absorber shall load the vehicle according the following equations:

IHP = TRLHP - PLHP - GTRL
Where: IHP is the dynamometer indicated, or set, horsepower.22 TRLHP is the track, or total, horsepower for a particular vehicle.
PLHP is the dynamometer parasitic loss horsepower.
GTRL is the generic tire/roll loss of a vehicle on the dynamometer.
TRLHP, PLHP, GTRL, and therefore IHP, are all expressed as three term polynomials of the type:
HP = A*Obmph + B*Obmph 2 + C*Obmph 3
Where: HP represents individual expressions relating IHP, TRLHP, PLHP, or GTRL as a function of velocity.
A, B, or C represent horsepower coefficients for the individual expressions relating IHP, TRLHP, PLHP, or GTRL as a function of velocity.
Obmph is the velocity in miles per hour.
Expressions for TRLHP, and GTRL are found in Appendices H and I.
(3) Inertia

. (i) Range . The dynamometer shall provide inertia simulation capability of 2000 to 5500 pounds for light duty vehicles and trucks less than or equal to 5500 pounds ETW. Dynamometers used for testing light duty vehicles and trucks over 5500 ETW shall have inertia simulation capability to set the inertia at the correct value as referenced in the EPA I/M Look-up Table.
(ii) Mechanical Inertia Simulation . The dynamometer shall be equipped with clutchable mechanical flywheels with inertia selectable to a 250 pound sensitivity. The tolerance on the base inertia weight and the flywheels shall be within 1% of the specified test weights. The test system shall be equipped with a method, independent from the flywheel selection system, that identifies which flywheels are actually rotating during the transient driving cycle.
(iii) Electric Inertia Simulation . Electric inertia simulation, or a combination of electric and mechanical simulation may be used in lieu of mechanical flywheels, provided that the performance of the electrically simulated inertia complies with the following specifications.
(A) System Response . The torque response to a step change shall be at least 90% of the command value within 200 milliseconds, and shall be within 2 percent of the commanded torque by 300 milliseconds after the command is issued. Any overshoot of the commanded torque value shall not exceed 25 percent of the torque value. Response time measurements shall be performed at 2000, base inertia, and 5500 pounds of inertia.
(B) Simulation Error . An inertia simulation error (ISE) shall be continuously calculated any time the actual dynamometer speed is between 10 and 60 mph. The average positive ISE over the driving cycle shall be calculated by the equation in §85.2226(a)(3)(iii)(C), and shall not exceed 2 percent of the inertia weight selected (IW s ) for the vehicle under test.23 (C) 

### ISE IW - I IW

s t

s 

### =     

 *100

Where: ISE = Inertia simulation error expressed in percent.

IW s = Total inertia desired, or selected, in pounds mass.

I t = Total inertia being simulated by the dynamometer in pounds mass.

(D) 

## I I 32.2 V (F F )dt t m m rl t 0

t 

## =+ −

= 

# ∫

Where: I t = Total inertia being simulated by the dynamometer in pounds mass.

I m = Base mechanical inertia of the dynamometer in pounds mass.
32.2 = Gravitational constant, (ft)(lbm)/(lbf)(sec 2 ).
V = Measured roll speed in feet/second.

F m = Force measured by the load cell converted to force at the roll surface in pounds.

F rl = Dynamometer road load expressed as a three term polynomial in pounds force at the measured roll speed.

t = Time in seconds.
(4) Dynamometer Parasitic Loss
(i) Friction Curves . The dynamometer internal friction curves, typically bearing and windage friction expressed as a function of velocity, shall be capable of being automatically measured, stored, and accurately accounted for over the IM240 driving cycle.
(ii) Friction Curve Definition . Parasitic loss friction shall be expressed in a tabular format as a function of velocity, or as a polynomial of the type:

PLHP = A p *Obmph + B p Obmph 2 + C p Obmph 3
Where: PLHP represents the dynamometer parasitic friction, expressed in horsepower.

A p , B p , and C p are coefficients relating a least squares fit of dynamometer friction and velocity.
Obmph is dynamometer roll surface velocity in miles per hour.24 (5) Rolls

. (i) Size and Type . The dynamometer shall be equipped with twin rolls. The rolls shall be coupled side to side. In addition, the front and rear rolls shall be coupled. The dynamometer roll diameter shall be between 8.5 and 21.0 inches. The spacing between the roll centers shall comply with the equation in §85.2226(a)(5)(iii). The dynamometer rolls shall accommodate an inside track width of 30 inches and an outside track width of at least 100 inches.
(ii) Roll Installation . Rolls shall be installed in the floor such that vehicles will be within ±5 degrees of horizontal.
(iii) Roll Spacing . The spacing between the roll centers shall comply with the following equation to within +0.5 inches and -0.25 inches.
Roll Spacing = (24.375 + D) * Sin 31.5 (
Where: Roll Spacing is the distance between the roll centerlines in inches.

D = Roll diameter in inches
(iv) Roll Surface . The surface finish and hardness shall be such that tire slippage is minimized when testing vehicles using the inertia weight and horsepower settings found in the EPA I/M Look-up Table while following the IM240 driving schedule, and that tire wear and noise are minimized. Knurled roll surfaces are acceptable.
(v) Test Distance and Vehicle Speed . The total number of dynamometer roll revolutions shall be used to calculate the distance traveled. Pulse counters may be used to calculate the distance directly if there are at least 16 pulses per revolution. The measurement of the actual roll distance for the composite and each phase of the transient driving cycle shall be accurate to within ±0.01 mile. The measurement of the roll speed shall be accurate to within ±0.1 mph over the IM240 driving schedule.
(vi) Vehicle Lift . A vehicle lift system located between the dynamometer rolls shall be provided to facilitate drive axle positioning and vehicle egress from the dynamometer.
(vii) Vehicle Restraint System . The dynamometer shall include a system of safely restraining the forward and side-to-side motion of front wheel drive vehicles, and the forward motion of rear wheel drive vehicles during the IM240 driving schedule, while allowing unobstructed ingress and egress from the dynamometer.
(6) Load Cell

. (i) Torque Measurement . The dynamometer shall have a torque measurement system accurate to within ±2% of full scale.
(ii) Dead Weights . Dead weights used to calibrate a torque meter or load cell shall be traceable to NIST and be accurate to within ±0.5%.
(iii) Dynamic Calibrations . Designs using an F = MA method for calibrating the load cell are also acceptable.
(7) Driver's Aid

.25 (i) Video Display . The dynamometer shall be equipped with a video display device able to be easily positioned to accommodate all test vehicles while clearly visible to the driver. The display shall have a method that allows the driver to accurately and smoothly follow the desired driving cycle.
(ii) Remote Capabilities . The dynamometer shall have a means of allowing the driver to start the test, perform an emergency stop, and perform other necessary and convenient functions related to the test while inside the vehicle.
(8) Other

. (i) Augmented Braking . Augmented braking shall be used during vehicle decelerations on the driving cycle. Augmented braking shall be actuated only when the negative force applied by the vehicle at the roll surface is greater than 110 pounds. If the augmented braking is not linked to driver braking, the driver shall be signaled to not accelerate during this period.
(ii) Cooling Fan . The cooling fan capacity shall be 5400 ±300 SCFM, positioned within 12 inches of the intake to the vehicle's cooling system, and avoid unrepresentative cooling of the engine and exhaust control system.
(9) All Wheel Drive Dynamometers

. (i) Design . The dynamometer shall meet the requirements for two wheel drive vehicles and be capable of testing traction control and all wheel drive vehicles in a safe manner without damaging the vehicle.
(ii) Wheelbase . The all wheel drive dynamometer shall be capable of testing vehicles having a wheelbase between 84 and 125 inches, or as necessary to meet the wheelbase values in the I/M Look-up Table. The system shall provide a locking mechanism to secure the roll at the desired wheelbase.
(iii) Speed Synchronization . Front and rear wheels shall maintain speed synchronization within ±0.1 mph.
(b) Constant Volume Sampler
(1) General Design Requirements

. (i) Venturi Type . A constant volume sampling (CVS) system of the critical flow venturi (CFV) or the sub-sonic venturi (SSV) type shall be used to collect vehicle exhaust samples. The CVS system and components shall generally conform to the specifications in §86.109-90.
(ii) CVS Flow Size . The CVS system shall be sized in a manner that prevents condensation in the dilute sample over the range of ambient conditions to be encountered during testing. A 700 SCFM system is assumed to satisfy this requirement. The range of ambient conditions may require the use of heated sample lines. Should heated sample lines be used , the lines and components shall be heated to a minimum of 120 ( F and a maximum of 250 ( F, which shall be monitored during the driving cycle.
(iii) CVS Compressor . The CVS compressor flow capacity shall be sufficient to maintain proper flow in the main CVS venturi with an adequate margin. For CFV CVSs the26 margin shall be sufficient to maintain choke flow. The capacity of the blower relative to the CFV flow capacity shall not be so large as to create a limited surge margin.
(iv) Materials . All materials in contact with exhaust gas shall be unaffected by and shall not affect the sample (i.e., the materials shall not react with the sample, and neither shall they taint the sample as a result of out gassing). Acceptable materials include stainless steel, Teflon ® , silicon rubber, and Tedlar ®

. (v) Alternative Designs . Alternative CVS specifications, materials, or designs may be allowed upon a determination by the Administrator, that for the purpose of properly conducting an approved short test, the evidence supporting such deviations will not significantly affect the proper measurement of emissions.
(2) Sample System

. (i) Sample Probe . The sample probe within the CVS shall be designed such that a continuous and adequate volume of sample is collected for analysis. The system shall have a method for determining if the sample collection system has deteriorated or malfunctioned such that an adequate sample is not being collected, or that the response time has deteriorated such that the time correlation for each emission constituent is no longer valid.
(ii) CVS Mixing Tee

. (A) Design and Effect . The mixing tee for diluting the vehicle exhaust with ambient air shall be at the vehicle tailpipe exit as in §86.109-90(a)(2)(iv). The dilution mixing tee shall be capable of collecting exhaust from all light-duty vehicle and light-duty truck exhaust systems. The design used shall not cause static pressure in the tailpipe to change such that the emission levels are significantly affected. A change of ±1.0 inch of water or less, as measured at the tailpipe, shall be acceptable.
(B) Locating Device . The mixing tee shall have a device for positively locating the tee relative to the tailpipe with respect to distance from the tailpipe, and with respect to positioning the exhaust stream from the tailpipe(s) in the center of the mixing tee flow area. The locating device, or the size of the entrance to the tee shall be such that if a vehicle moves laterally from one extreme position on the dynamometer to the other extreme, that mixing tee will collect all of the exhaust sample.
(iii) Dual Exhaust . For dual exhaust systems, the design used shall insure that each leg of the sample collection system maintains equal flow. Equal flow will be assumed if the design of the "Tee" intersection for the dual CVS hoses is a "Y" that minimizes the flow loss from each leg of the "Y," if each leg of the dual exhaust collection system is approximately equal in length (± 1 foot), and if the dilution area at the end of each leg is approximately equal. In addition, the CVS flow capacity shall be such that the entrance flow velocity for each leg of the dual exhaust system is sufficient to entrain all of the vehicle's exhaust from each tailpipe.
(iv) Background Sample . The mixing tee shall be used to collect the background sample. The position of the mixing tee for taking the background sample shall be within 12 lateral and 12 longitudinal feet of the position during the transient driving cycle, and approximately 4 vertical feet from the floor.27 (v) Integrated Sample . A continuous dilute sample shall be provided for integration by the analytical instruments in a manner similar to the method for collecting bag samples as described in §86.109-90.
(c) Analytical Instruments
(1) General Requirements

. (i) Instrument Specifications . The emission analysis system shall automatically sample, integrate, and record the specified emission values for HC, CO, CO2, and NOx. Performance of the analytical instruments with respect to accuracy and precision, drift, interferences, noise, etc. shall be similar to instruments used for testing under §86 Subparts B, D, and N. Analytical instruments shall perform in this manner in the full range of operating conditions in the lane environment.
(ii) Alternative Designs . Alternative analytic equipment specifications, materials, designs, or detection methods may be allowed upon a determination by the Administrator, that for the purpose of properly conducting an approved short test, the evidence supporting such deviations will not significantly affect the proper measurement of emissions.
(2) Detection Methods and Instrument Ranges
(i) Total Hydrocarbon Analysis . Total hydrocarbon analysis shall be determined by a flame ionization detector. If a 700 SCFM CVS is used, the analyzer calibration curve shall cover at least the range of 0 ppmC to 2,000 ppmC. Use of a different CVS flow capacity shall require an adjustment to these ranges. Appropriate documentation supporting any adjustment in ranges shall be available. The calibration curve must comply with the quality control specifications in §85.2234(d) for calibration curve generation.
(ii) Carbon Monoxide Analysis . CO analysis shall be determined using a non-dispersive infrared analyzer. If a 700 SCFM CVS is used, CO analysis shall cover at least the range of 0 ppm to 10,000 ppm (1%). In order to meet the calibration curve requirements, two CO analyzers may be required - one from 0 to 1000 or 2000 ppm, and one from 0 to 1% CO. Use of a different CVS flow capacity shall require an adjustment to these ranges. Appropriate documentation supporting any adjustment in ranges shall be available. The calibration curve requirements and the quality control specifications in §85.2234(d) apply to both analyzers.
(iii) Carbon Dioxide Analysis . CO 2 analysis shall be determined using an NDIR analyzer. If a 700 SCFM CVS is used, CO 2 analysis shall cover at least the range of 0 ppm to 40,000 ppm (4%). Use of a different CVS flow capacity shall require an adjustment to these ranges. Appropriate documentation supporting any adjustment in ranges shall be available. The calibration curve must comply with the quality control specifications in §85.2234(d) for calibration curve generation.
(iv) Oxides of Nitrogen Analysis . NOx analysis shall be determined using chemiluminescence. The NOx measurement shall be the sum of nitrogen oxide and nitrogen dioxide. Alternatively, NO x measurements may be made by re-calibrating the chemiluminescence analyzer in NO only mode, then running the analyzer in NO only mode and multiplying the result by 1.03. This will eliminate the need for the converter and flow balance checks in §85.2234(d)(5) and §85.2234(d)(6).
If a 700 SCFM CVS is used, the NOx analysis shall cover at least the range of 0 ppm to 500 ppm. Use of a different CVS flow capacity shall require an adjustment to these28 ranges. Appropriate documentation supporting any adjustment in ranges shall be available. The calibration curve must comply with the quality control specifications in §85.2234(d) for calibration curve generation.
(3) System Response Requirements . Historically, continuously integrated emission analyzers have been required to have a response time of 1.5 seconds or less to 90% of a step change, where a step change was 60% of full scale or better. System response times between a step change at the probe and reading 90% of the change shall be less than 10 seconds.
(4) Integration Requirements

. (i) Sampling Frequency . The analyzer voltage responses, CVS pressure(s), CVS temperature(s), dynamometer speed, and dynamometer power shall be sampled at a frequency of no less than 5 Hertz, and the voltage levels shall be averaged over 1 second intervals.
(ii) Time Alignment . The system shall properly time correlate each analyzer signal and the CVS signals to the driving trace.
(iii) Engineering Units . The one-second average analyzer voltage levels shall be converted to concentrations by the analyzer calibration curves. Corrected concentrations for each gas shall be derived by subtracting the pre-test background concentrations from the measured concentrations, according to the method in §85.2205(b). The corrected concentrations shall be converted to grams, for each second, using the equations specified in §85.2205(b) to combine the concentrations with the CVS flow over the same interval. The grams of emissions per test phase shall be determined using the equations in §85.2205(b).
(iv) Multiple Analyzers . When multiple analyzers are used for any constituent, the integration system shall simultaneously integrate both analyzers. The integrated values for the lowest analyzer in range shall be used for each second.
(v) Background Samples . For all constituents, the background concentration levels from the lowest range shall be used, including the case where multiple analyzers may have been used.
(5) Analytical System Design

. (i) Materials . All materials in contact with exhaust gas prior to and throughout the measurement portion of the system shall be unaffected by and shall not affect the sample (i.e., the materials shall not react with the sample, and neither shall they taint the sample as a result of out gassing). Acceptable materials include stainless steel, Teflon, silicon rubber, and Tedlar ®.
(ii) System Filters . The sample system shall have an easily replaceable filter element to prevent particulate matter from reducing the reliability of the analytical system. The filter element shall provide for reliable sealing after filter element changes. If the sample line is heated, the filter system shall also be heated.
(iii) Availability of Intermediate Calculation Variables . Upon request prior to a test, all intermediate calculation variables shall be available to be downloaded to electronic files or hard copy. These variables shall include those that calculate the vehicle emission test results, perform emission analyzer and dynamometer function checks, and perform quality assurance and quality control measurements.29 §85.2227 Evaporative System Equipment Specifications

(a) General Requirements
(1) Equipment Design . Automated and computerized test systems shall be used for the evaporative system tests wherever they are appropriate. Pass/fail decisions shall be made automatically. The systems shall be tamper resistant and designed to avoid damage to the vehicle during installation, testing, and removal.
(2) Alternative Systems . Alternative purge, pressure, or gas cap test equipment specifications or designs may be proposed by a State if they are supported by data and approved in advance by the Administrator.

(b) Evaporative System Pressure Test Equipment
(1) General Requirements

. (i) Alternative Designs . Flow measurement or flow comparator leak detection methods are acceptable if supported by data and approved in advance by the Administrator. Standards for flow based methods have not been established.
(ii) Pressurizing Gas . Nitrogen, or an equivalent non-toxic, non-greenhouse, inert gas, shall be used for pressurizing the evaporative system. Air should only be used if the pressurized vapor space is outside the combustible limits for the vehicle fuel type.
(iii) Automatic Operation . The process for filling the vapor space, monitoring compliance, recording data, and making a pass/fail decision shall be automatic. After the determination that the evaporative system has been filled to the specified pressure level, and upon initiation of the test, the pressure level in the evaporative system shall be recorded at a frequency of no less than 1 Hertz until the conclusion of the test.
(iv) Test Abort . The system shall be equipped with an abort system that positively shuts off and relieves pressure. The abort system shall be capable of being activated quickly and conveniently by the inspector should the need arise.
(v) Grounding . A fillpipe pressure test must be designed to prevent electrostatic discharge that would pose a flammability risk during the test.
(2) Adapters and Clamps

. (i) Fuel Inlet Adapters . Adapters attached to the fuel fillpipe inlet shall be used to supply pressurized gas into the fuel tank. Adapters shall be available for at least 95 percent of the fuel inlets that are used on U.S. light duty vehicles and light duty trucks for the model years covered by the program.
(ii) Hose Clamp . The hose clamp used for the fuel inlet pressure test shall be designed to apply only enough pressure to close the flexible vent line between the fuel tank and canister without damaging it. The nose of the clamp shall be smooth-surfaced or otherwise designed to avoid damage to the vent line.
(3) Pressure Gauge . The device for measuring pressure shall have a minimum range of 0 to 28 inches of water and an accuracy of + 0.3 inches of water, or 2% of point, whichever is greater.
(c) Gas Cap Test Equipment30 (1) General Requirements

. (i) Alternative Designs . Leak testers failing gas caps with a test standard below 60 cc/min at 30 in. WC are permissible provided they do not falsely fail gas caps designed to meet vehicle manufacturer OEM specifications, are repeatable and accurate in a centralized I/M environment, and demonstrate quantifiable reductions in real world mass emissions. OEM leak rates for individual manufacturers are proprietary. Information submitted to EPA shows some vehicle manufacturers had maximum leak rates up to 20 cc/min at 30 inches of WC.
(ii) Gas Cap Adapters . The gas cap tester shall accommodate at least 95 percent of the gas caps that are used on U.S. light duty vehicles and trucks for the model years covered by the gas cap test program.
(iii) Pressurizing Gas . Air, Nitrogen, or an equivalent non-toxic, non-greenhouse, inert gas, shall be used for pressurizing the gas cap tester.
(iv) Automatic Operation . The process for making a pass/fail decision shall be automated. The gas cap tester shall provide for automated pass/fail determination and automated transfer of the pass/fail result to a host computer, i.e. a real-time data link.
(v) Over-Pressurization . The tester shall control the supply pressure of the gas used for pressure decay, direct flow measurement, or flow comparison methods and prevent over-pressurization.
(2) Gas Cap Tester . Gas cap testers employing internal reference orifices, or pressure measurement devices, shall be traceable to NIST flow or pressure measurement standards.
(i) Range . The tester shall identify passing gas caps with a leak rate equal to or less than 60 cc/min of air at 30 inches of WC, and failing caps with leak rates more than 60 cc/min at 30 inches of WC at reference conditions of 70F and 1 atm.
(ii) Filter . A serviceable air filter shall be incorporated upstream of flow orifices.
(iii) Power Supply . Battery powered testers shall be equipped with an automatic shutoff and a low-battery indicator.
(iv) Accuracy . Pressure decay, direct flow measurement, or flow comparison methods shall be accurate to ±3 cc/min at the 60 cc/min flow standard.
(v) Reference Caps and Orifices . NIST traceable reference passing fuel caps or orifices of nominal 52-56 cc/min, and NIST traceable reference failing fuel caps or orifices of nominal 64-68 cc/min shall be supplied with the tester for daily verification tests.
(vi) Head Space . Pressure decay methods shall employ a head space sized to produce correct results at the 60 cc/min at 30 in. WC standard.31 §85.2234 IM240 Test Quality Control Requirements
(a) General Requirements
(1) Manufacturers' Recommendations . Manufacturers' recommendations for equipment installation, calibration, and maintenance, shall be followed.
(2) Statistical Process Control . SPC tracking methods shall be established for appropriate equipment checks and custom diagnostic or verification tests.
(3) Modifications to Quality Control Requirements . Changes to the type or frequency of the quality checks are permitted provided they are based on SPC analysis, or data from experimental studies.
(b) Dynamometer
(1) Dynamometer Manufacturer Recommendations
(i) Minimum Requirements . The dynamometer manufacturer's requirements for periodic diagnostic checks, calibration, scheduled maintenance, and recommended quality control monitoring shall be followed.
(ii) Warm-up Requirements . The dynamometer manufacturer's procedure for insuring proper warm-up over a 35 to 110°F temperature range shall be followed.
(2) Coast Down Testing
(i) Frequency . Dynamometers with electric and mechanical inertia simulation shall receive a daily unloaded (vehicle off the dynamometer) coast down check over the range of 60 to 10 mph. This daily check shall be run at alternating combinations of inertia and road load settings. Dynamometers using only mechanical flywheels for inertia simulation shall also receive additional weekly coast down checks to properly characterize the friction at other combinations of flywheel weights. The number of these coast downs shall be established based on the dynamometer design and quality control monitoring.
(ii) Load Settings . Inertia and power absorber settings shall be representative of vehicle test conditions, and shall result in nominal coast down times of 15-20 seconds when time is measured between 55 and 45 mph, and 22-33 seconds when time is measured between 22 and 18 mph. Inertia settings for clutchable flywheel dynamometers are discretionary but should attempt to be above and below the base inertia of the dynamometer and represent high and low inertia weight vehicles.
(iii) Quality Control Limits . Actual control limits for the coast down tests shall be established by statistical process control practices. The 55 to 45 mph and 22 to 18 mph coastdown times shall be within ±1 second, and ± 6 seconds, respectively, of the theoretical coast down times. These ±1 and ±6 second limits are based on the 15-20 and 22-33 second coastdown times in the preceding paragraph. Theoretical coastdown time is based on the following equation: 

# ( ) t 0.5 * ETW 32.2 * (V V ) 550* HP I 2 F 2



### = −

Where: t = The coastdown time in seconds32 ETW = The Equivalent Test Weight in pounds

V I = The initial roll velocity in feet/second

V F = The final roll velocity in feet/second
IHP = The dynamometer indicated horsepower
An alternative to the ±1 or ±6 second limits is to perform an unloaded coastdown from 60 to 10 mph and reduce the speed/time data to produce a polynomial relationship between horsepower (or force) versus time. The measured horsepower curve shall be within ±0.25 horsepower or ±3% of point, whichever is greatest.
Dynamometers which exceed specific SPC limits or the coast down limits presented above, shall be removed from service until corrective action is taken to assure the dynamometer is performing satisfactorily.
(3) Parasitic Loss Checks
(i) Frequency . Checks of the parasitic loss curve shall be conducted at a frequency recommended by the dynamometer manufacturer, as required by inspection of quality control data, or as necessary following service to the dynamometer.
(ii) Quality Control Limits . Parasitic loss measurements shall be measured between 10 and 60 mph. Identification of outlier data shall be established by examination of quality control data.
Dynamometers which exceed dynamometer specific SPC limits for parasitic loss checks shall be removed from service until corrective action is taken to ensure the dynamometer is performing satisfactorily.
(4) Roll Speed

. (i) Frequency . Weekly checks of the roll speed measurement system shall be made, or at intervals recommended by the dynamometer manufacturer, or as required by inspection of quality control data, or as necessary following service to the dynamometer.
(ii) Quality Control Limits . If roll speed checks are conducted, the measured roll speed shall agree to within ±0.1 mph of the calibration standard. Dynamometers which exceed the 0.1 mph limit shall be removed from service until corrective action is taken to ensure the dynamometer is performing satisfactorily.
(5) Acceptance Criteria
(i) General . Prior to dynamometer acceptance, the dynamometer shall demonstrate compliance with the design criteria for the load cell accuracy, power absorber curve accuracy, roll geometry, dynamometer simulation error, electric inertia response time, and parasitic loss measurement. These criteria are specified in §85.2226(a).
(ii) Base Inertia Verification . The base inertia of dynamometers shall be verified before dynamometer acceptance. The base inertia weight plus individual prime weights shall be verified for dynamometers which simulate inertia with mechanical flywheels. The33 specified base inertia shall agree with acceptance testing measurements within ±10 pounds.
(iii) Independent Speed and Distance Verification . An independent method of verifying dynamometer roll speed and distance measurement accuracy shall be performed before dynamometer acceptance to ensure compliance with the specifications in §85.2226(a)(5)(v).
(c) Constant Volume Sampler
(1) Flow Calibration . The flow of the CVS shall be calibrated at six flow rates upon initial installation, 6 months following installation, and every 12 months thereafter. SPC tracer gas injection data may be used to verify CVS flow in lieu of the annual calibration requirement. This data shall be made available to EPA upon request. The flow rates shall include the nominal rated flow-rate and a rate below the rated flow-rate for both critical flow venturis and subsonic venturis, and a flow-rate above the rated flow for sub-sonic venturis. The flow calibration points shall cover the range of variation in flow that typically occurs when testing. A complete calibration shall be performed following repairs to the CVS that could affect flow.
(2) System Check . CVS flow calibration at the nominal CVS design flow shall be checked once per day using a procedure equivalent to that in §86.119(c). Deviations greater than ±4% shall result in automatic lockout of official testing until corrected. At the State’s discretion, the frequency of this may be reduced to weekly.
(3) Cleaning Flow Passages . The sample probe shall be checked at least once per month, and cleaned if necessary in order to maintain proper sample flow. CVS venturi passages shall be checked once per year and cleaned if necessary.
(4) Probe Flow . The indicator identifying the presence of proper probe flow for the system design (e.g., proportional flow for CFV systems, minimum flow for time correlation of different analyzers) shall be checked on a daily basis. Lack of proper flow shall require corrective action.
(5) Leak Check . The vacuum portion of the sample system shall be checked for leaks on a daily basis and each time the system is serviced.
(6) System Response Time Check . The response time of each analyzer shall be checked upon initial installation and after each repair or modification to the flow system that would reasonably be expected to affect the response time, and at least once per week. The check shall include the complete sample system from the sample probe to the analyzer. Statistical process control shall be used to monitor compliance and establish quality control limits. At a minimum, response time measurements that deviate significantly from the average response time for all CVS systems designed to the same specification in the program shall require corrective action before testing may resume.
(7) Mixing Tee Acceptance Test

. (i) Static Pressure Requirement . The design of the mixing tee shall be evaluated by running the transient driving cycle on at least two vehicles, representing the high and low ends of engine displacement and inertia. Changes in the static tailpipe pressure with and without CVS, measured on a second-by-second basis within 3 inches of the end of the tailpipe, shall not exceed ±1.0 inch of water.
(ii) Single Exhaust System . The ability of the mixing tee design to capture all of the exhaust as a vehicle moves laterally from one extreme position on the dynamometer to the other extreme shall be evaluated with back-to-back testing of three vehicles,34representing the high and low ends of engine displacement and inertia. The back-toback testing shall be done with the mixing tee at the tailpipe and with an airtight connection to the tailpipe (i.e., the mixing tee will be effectively moved downstream, as in typical FTP testing). The difference in carbon-balance fuel economy between the mixing tee located at the vehicle and the positive connection shall be no greater than 5%.
(iii) Dual Exhaust System . The design of the dual exhaust system shall be evaluated with back-to-back testing of three vehicles, representing the high and low ends of engine displacement and inertia, with an airtight connection to the tailpipe (i.e., the mixing tee will be effectively moved downstream, as in typical FTP testing, for these qualification tests). The difference in carbon-balance fuel economy between the two methods shall be no greater than 5%.
(d) Analysis System
(1) Calibration Curve Generation

. (i) Initial Installation Calibration . Upon initial installation, calibration curves shall be generated for each analyzer. If an analyzer has more than one measurement transducer, each transducer shall be considered as a separate analyzer in the analysis system for the purposes of curve generation and analysis system checks.
(ii) Complete Range Calibration . The calibration curve shall consider the entire range of the analyzer as one curve.
(iii) Calibration Point Spacing . When both a low range analyzer and a high range analyzer are used for a single gas (e.g., CO), the high range analyzer shall use at least 5 calibration points plus zero in the lower portion of the high range scale corresponding to approximately 100% of the full-scale value of the low range analyzer. For all analyzers, at least 5 calibration points shall be used to define the calibration curve above the 5 lower calibration points. The calibration zero gas shall be used to set the analyzer to zero.
Alternatively, gas dividers may be used to generate a 10-point calibration curve employing equally spaced points.
(iv) Calibration Curve Fits . The calibration curves generated shall be a polynomial of the best fit and no greater than 4th order, and shall fit the data within ±2.0% at each calibration point as specified in §86.120-90, §86.122-78, §86.123-78, and §86.124-78.
(v) Mid-scale Verification . Each curve shall be verified for each analyzer with a confirming calibration standard between 30-60% of full scale that is not used for curve generation. Each confirming standard shall be measured by the curve within 2.5%.
(2) Spanning Frequency . The zero and up-scale span points shall be checked at 3 hour intervals following the daily mid-scale curve check specified in §85.2234(d)(4) and adjusted if necessary. If the up-scale span point drifts by more than 2.0% from the previous check official testing shall be prevented and corrective action shall be taken to bring the system into compliance. If the zero point drifts by more than 2 ppmC HC, 1 ppm NO x , 10 ppm CO, or 40 ppm CO 2 , official testing shall be prevented and corrective action shall be taken to bring the system into compliance, or the unit may be zeroed prior to each test.
(3) Limit Check . The tolerance on the initial adjustment of a change in the up-scale span point shall be ± 2% of point on the appropriate analyzer range. A software algorithm to perform the zero and span adjustment and subsequent calibration curve adjustment shall be used.35 Cumulative software up-scale zero and span adjustments greater than ± 10% from the latest calibration curve shall cause official testing to be prevented and corrective action shall be taken to bring the system into compliance. Zero and span potentiometers on the analyzer may be used between calibrations to minimize software corrections; however, a zero and span check shall be performed after any adjustment of a potentiometer.
(4) Daily Calibration Checks . The curve for each analyzer shall be checked and adjusted to correctly read zero using a working zero gas, and an up-scale span gas within the tolerance in §85.2234(d)(3), and then by reading a mid-scale span gas within 2.5% of point, on each operating day prior to vehicle testing. If the analyzer does not read the mid-scale span point within 2.5% of point, the analyzer shall automatically be prevented from official testing. Theup-scale span gas concentration for each analyzer may be up to 90% of full scale, and the midpoint concentration shall correspond to approximately 15% of full scale.
(5) Monthly NO x Converter Checks . The converter efficiency of the NO 2 to NO converter shall be checked on a monthly basis. The check shall be equivalent to §86.123-78 (for reference see TSD Form 305-01) except that the concentration of the NO gas shall be in the range of 75-400 ppm. Alternative methods may be used if approved by the Administrator.
This check is not required if the measurements of NO only are being performed per 85.2226(c)(2)(iv) with the NOx analyzer run in NO only mode.
(6) Monthly NO/NO x Flow Balance . The flow balance between the NO and NO x test modes shall be checked monthly. The check may be combined with the NO x converter check as illustrated in EPA NVFEL test laboratory Form 305-01.
This check is not required if the measurements of NO only are being performed per 85.2226(c)(2)(iv) with the NOx analyzer run in NO only mode.
(7) Monthly Calibration Checks . The basic calibration curve shall be verified monthly by the same procedure used to generate the curve in §85.2234(d)(1), and to the same tolerances.
(8) FID Check

. (i) FID Optimization . Upon initial operation, and after maintenance to the detector, each FID shall be checked, and adjusted if necessary, for proper peaking and characterization using the procedures described in SAE Paper No. 770141 or by analyzer manufacturer recommended procedures.
(ii) Methane Response . The response of each FID to a methane concentration of approximately 50 ppm CH 4 shall be checked once per month. If the response is outside of the range of 1.00 to 1.30, corrective action shall be taken to bring the FID response within this range. The response shall be computed by the equation in §85.2234(d)(8)(iii). The frequency of this check may be reduced by providing 1 year of data for each analyzer that demonstrates less frequent checks are acceptable. If less frequent checks are used, the response check data shall be made available to EPA upon request. (iii) Methane Response Definition . Ratio of Methane Response = FID response to CH 4 gas in ppmC /ppm CH 4 in the cylinder.
(9) Mid-Span or Cross-Checks . On a quarterly basis, and whenever gas bottles are changed, each analyzer in a given facility shall analyze a sample of a test gas. The test gas used for these cross checks shall be a 1% NIST traceable mid-span bottle and the same bottle shall be used for all36 analyzers at a given facility. The analyzer shall read this mid-span gas within 2.5% of the labeled value or the analyzer shall be taken out of service.
Alternatively, all gas bottles entering a facility shall be verified using a master bench and NIST traceable SRM, CRM, NTRM, or RGM gases. Quarterly checks would then be performed on each analyzer using three points at 25%, 50%, and 75% of full scale.
(10) Interference Test . The CO analyzer shall be checked for water vapor interference prior to initial service. The interference limits in this paragraph shall apply to analyzers used with a CVS of 700 SCFM or greater. For analyzers used with lower flow rate CVS units, the allowable interference response shall be proportionately adjusted downward.
(i) CO Analyzer . A CO instrument will be considered to be essentially free of CO 2 and water vapor interference if its response to a mixture of 3% CO 2 in N 2 which has been bubbled through water at 20°C produces an equivalent CO response, as measured on the most sensitive CO range, which is less than 1% of full scale.
(e) Gases (1) General Requirements . Gas blends may contain up to three of any of the following components: HC, CO, CO 2 , and NO. The HC component shall be propane. The diluent for blends containing HC shall be air. The diluent for blends containing NO shall be N 2 . CO and CO 2 may be used with either air or N 2 as the diluent. Blends containing four interest components may be used only if approved by the Administrator. Blends containing NO 2 shall also require approval by the Administrator prior to use, except if used to perform the NO x converter check specified in §85.2234(d)(5). Any interference effects between components in a gas blend shall be addressed in the quality control and quality assurance process. When a gas audit of the analytical system is performed, the auditor shall indicate whether CO 2 is present in the audit gas mixture prior to performing the audit.
(2) Calibration Gases . Gases used to generate and check calibration curves shall be traceable to a NIST SRM, CRM, NTRM, or RGM and have a stated uncertainty to within 1% of the standard by gas comparison methods. Calibration zero gas shall be used when using a gas divider to generate intermediary calibration gases.
(3) Span Gases . Gases used for up-scale span adjustment, cross-checks, and for mid-scale span checks shall be traceable to NIST SRM, CRM, NTRM, or RGM and have a stated uncertainty to within 2% of the standard by gas comparison methods. Span gas concentrations shall be verified immediately after a monthly calibration curve check and before being put into service. If the reading on the span gases exceeds 2.5% of the label value, the system or gases shall be taken out of service until corrective action is taken. When a gas divider is used to generate span gases, the diluent gas shall not have impurities any greater than the working zero gas.
(4) Calibration Zero Gas . The impurities in the calibration zero gas shall not exceed 0.1 ppmC, 0.5 ppm CO, 1 ppm CO 2 , and 0.1 ppm NO. Calibration zero grade air shall be used for the FID zero calibration gas. Calibration zero grade nitrogen or calibration zero grade air shall be used for CO, CO 2 , and NO x zero calibration gases.
(5) Working Zero Gas . The impurities in working zero grade gases shall not exceed 1 ppmC, 2 ppm CO, 400 ppm CO 2 , and 0.3 ppm NO x . Working zero grade air or calibration zero grade air shall be used for the FID zero span gas. Working or calibration zero grade nitrogen or air shall be used for CO, CO 2 , and NO x zero span gases.37 (6) FID Fuel . The fuel for the FID shall consist of a mixture of 40% (+ 2%) hydrogen, and the balance helium. The FID oxidizer shall be zero grade air, which can consist of artificial air containing 18 to 21 mole percent of oxygen.
(7) Gas Naming Protocol . Gases used for calibration or auditing shall be named according to a written established practice that has been approved by the Administrator. An accepted gas naming procedure for I/M test purposes is the IM240 Gas Certification Protocol dated 10/27/94, or its latest revision. Copies of the 10/27/94 document are available upon request from EPA.
(f) Overall System Performance
(1) Emission Levels . For each test lane, the average, median, 10th percentile and 90th percentile of the composite emissions (HC, CO, CO 2 , and NO x ) measured shall be monitored on a monthly basis. Differences in the monthly average of greater than ±10% by any one lane from thefacility-average or combined facility-average, or by any one facility from the combined facilityaverage shall require an investigation to determine whether the single lane or facility has a systematic equipment or operating error or difference. Where it can be determined that the averages from one facility (or facilities) are offset from the average of the other facilities based on the mix of vehicles tested, the ±10% limit shall be compared to the expected offset. If systematic equipment or operating errors or differences causing the offset are found, such errors shall be corrected. The sample period may be adjusted to assure that a reasonably random sample of vehicles was tested in each lane.
(2) Pass/Fail Status . The average number of passing vehicles and the average number of failing vehicles shall be monitored monthly for each test lane. Differences in the monthly average of greater than ±15% by any one lane from the facility-average or combined facility-average, or by any one facility from the combined facility-average shall require an investigation to determine whether the single lane or facility has a systematic equipment or operating error or difference. Where it can be determined that the averages from one facility (or facilities) are offset from the average of the other facilities based on the mix of vehicles tested, the ±15% limit shall be compared to the expected offset. If systematic equipment or operating errors or differences causing the offset are found, such errors shall be corrected. The sample period may be adjusted to assure that a reasonably random sample of vehicles was tested in each lane.
(g) Control Charts
(1) General Requirements . Control charts and Statistical Process Control theory shall be used to determine, forecast, and maintain performance of each test lane, each facility, and all facilities in a given network. The control charts shall cover the performance of key parameters in the test system. When key parameters approach control chart limits, close monitoring of such systems shall be initiated and corrective actions shall be taken when needed to prevent such systems from exceeding control chart limits. If any key parameter exceeds the control chart limits, corrective action shall be taken to bring the system into compliance. The control chart limits specified are those values listed for the test procedures, the equipment specifications, and the quality control specifications that cause a test to be voided or require equipment to be removed from service. These values are "fit for use" limits, unlike a strict interpretation of SPC control chart theory which may use tighter limits to define the process. The test facility is encouraged to apply SPC strict control chart theory to determine when equipment or processes could be improved. No action shall be required until the equipment or process exceeds the "fit for use limits" specified in this section.
(2) Control Charts for Individual Test Lanes . In general, control charts for individual test lanes shall include parameters that will allow the cause for abnormal performance of a test lane to be pinpointed to individual systems or components. Test lane control charts shall include at a minimum:38 (i) Difference between theoretical and measured coast-down times
(ii) Difference between theoretical and measured CVS flow
(iii) Up-scale span change from last up-scale span (not required if software corrections are tracked)
(iv) Mathematical or software correction to the calibration curve as a result of an up-scale span change (if used)
(v) Difference between the analyzer response to the daily cross-check, and the test gas concentration
(vi) The system response time
(vii) FID CH 4 response ratio
(viii) Difference between theoretical or measured values for other parameters measured during quality assurance procedures
(3) Control Charts for Individual Facilities . Control charts for individual facilities shall consist of the test lane control charts for each test lane at the facility.
(4) Control Charts of Individual Inspectors . Control charts for individual inspectors shall include parameters that will allow the cause for abnormal performance to be evaluated, such as technician IM240 driving quality.39 §85.2235 Evaporative Test Quality Control Requirements
(a) General Requirements
(1) Manufacturers' Recommendations . Manufacturers' recommendations for equipment installation, calibration, and maintenance shall be followed.
(2) Statistical Process Control . SPC tracking methods shall be established for appropriate equipment checks and custom diagnostic or verification tests.
(3) Modifications to Quality Control Requirements . Changes to the type or frequency of the quality checks are permitted provided they are based on SPC analysis, or data from experimental studies.
(b) Evaporative System Pressure Checks (1) Daily Checks . The pressure check system shall be pressurized to 28±1 inch of WC and monitored for a loss of pressure. Pressure testing shall be stopped and corrective action shall be taken to repair the system if a loss of pressure of more than 0.4 inches of WC is observed over a 15 second period.
(2) Bi- Weekly Check . Pressure gauges or measurement devices shall be checked on a bi-weekly basis against a reference gauge or device equal to or better than the specified performance requirements. Deviations exceeding the specified accuracy shall require corrective action.
(c) Evaporative System Gas Cap Checks
(1) Gas Cap Tester

. (i) Daily Checks . The tester shall be verified daily by testing and correctly identifying passing and failing reference gas caps or flow orifices as specified in §85.2227(d)(2)(v). Reference caps and orifices shall be stored in a dirt and dust free manner to prevent clogging and changes in flow rates. Reference caps and orifices shall be stored at the same temperature as the cap tester to provide accurate flow reference.
(ii) Corrective Action . Gas cap testing shall be stopped and corrective action taken to repair the tester if passing and failing reference gas caps or flow orifices cannot be correctly identified.
(iii) Reference Caps or Orifices - Flow Checks . Independent flow bench verification of the reference gas caps and flow orifices shall be conducted before initial usage, and at six month intervals, or as recommended by the cap tester manufacturer or as suggested by analysis of quality control data. The bench flow verification results shall be traceable to NIST.
(iv) Comparator Orifices - Flow Checks . Internal flow standard orifices for direct flow measurement methods, or flow comparator methods, shall be traceable to a NIST reference.
(2) Gas Cap Adapters

. (i) Leak Checks . The gas cap adapters shall be checked for visual damage daily and leak checked weekly, or by following the recommendations of the gas cap adapters supplier.40 §85.2239 Test Report

(a) General Test Report Information
(1) Vehicle Description

. (i) License plate number (ii) Vehicle identification number (iii) Weight class (iv) Odometer reading
(2) Date and Time . Date and end time of the tailpipe emission measurement test.
(3) Identification Information . Name or identification number of the individual performing the test and the location of the test station and lane.
(4) Warranty Provisions . For failed vehicles, a statement indicating the availability of warranty coverage as provided in Section 207 of the Clean Air Act.
(5) Certification . A statement certifying that the short tests were performed in accordance with applicable regulations.
(b) Tests and Results
(1) Test Types and Standards . The test report shall indicate the types of tests performed on the vehicle and the test standards for each. Test standards shall be displayed to the appropriate number of significant digits as in §85.2205(a). For the IM240 the reported standards shall be the composite test standards.
(2) Test Scores . The test report shall show the scores for each test performed. Test scores shall be displayed to the same number of significant digits as the standards.
(3) IM240 Scores . The reported score for the IM240 shall be in units of grams per mile and shall be selected based upon the following:
(i) Passing Scores - Composite IM240 . If the emissions of any exhaust component on the composite IM240 are below the applicable standard in §85.2205(a), then the vehicle shall pass for that constituent and the composite score shall be reported.
(ii) Passing Scores - Phase 2 . If the emissions of any exhaust component on the composite IM240 exceed the applicable standard in §85.2205(a) but are below the Phase 2 standard, then the vehicle shall pass for that component and the Phase 2 score shall be reported.
(iii) Failing Scores . If the emissions of any exhaust component on the composite IM240 exceed the applicable standard in §85.2205(a)(2) through §85.2205(a)(4) and exceed the Two Ways to Pass Standard as described in §85.2205(a)(1), then the vehicle shall fail for that component and the composite score shall be reported.
(iv) Emission Reporting . If a passing decision is made for all three exhaust components on the IM240 before the end of the full driving cycle according to the criteria described in §85.2205(a)(4), the passing results and reported emissions levels shall be those obtained at the time the test is terminated. Emission levels for the IM240 shall be reported in grams per mile calculated using the full IM240 mileage (not actual41 mileage). The emission standards reported shall be the composite standards (i.e., not the fast-pass standards).
(4) Pressure Test Scores . The score(s) for the pressure test(s) shall be reported as a change in pressure expressed in inches of water.
(5) Test Results . The test report shall indicate the pass/fail result for each test performed and the overall result. In the case of exhaust emission tests, the report shall indicate the pass/fail status for each component for which standards apply.
(6) Second-by-Second Measurements . For vehicles failing the IM240, a graph showing the secondby-second emission levels (see following example), for each exhaust component in grams per mile equivalent. The plots of HC, CO, NOx, and CO2 are expressed in units of “gram per mile equivalent,” or:
Y = (X)*(239 seconds)/(1.959 miles)
Where: Y = Grams per mile equivalent calculated on a second by second basis
X = Grams of HC, CO, NOx, or CO2 calculated during the one second interval

(c) Recommended IM240 Second-By-Second Emissions Report

Test Number 4719 Model Year 1988 Test Weight 3000 Emission Actual Cut point Make XXXX TRLHP 14.7 HC (gpm) 2.45 0.80

Model YYYY Traction Control No CO (gpm) 23.1 15.0

Cylinders 4 ABS No NOx (gpm) 0.71 2.00

Transmission Auto Gas Cap Test Yes CO2 (gpm) 279 n/a

Vehicle Type LDGV Press Test Yes

The following figures provide illustrations of the recommended second-by-second emissions output.42 0.0 1.0 2.0 3.0 4.0 5.0 6.0

0 15 30 45 60

0 2 4 6 8 10 12



### Seconds 0 20 40 60 80 100 120 140 160 180 200 220 240 2000
1500
1000
500

0 0 10 20 30 40 50 60

mph

0 10 20 30 40 50 60

mph

0 10 20 30 40 50 60

mph

0 10 20 30 40 50 60

mph 

### HC gpme

CO gpme

NOx gpme

CO2 gpme43 §85.2241 Terms
(1) ALVW: Adjusted Loaded Vehicle Weight: (VCW + GVWR)/2 (2) CFV: Critical Flow Venturi (3) CH 4 : Methane (4) CO 2 : Carbon dioxide (5) CO: Carbon monoxide (6) CRM: Certified Reference Material (7) CVS: Constant Volume Sampler (8) ETW: Equivalent Test Weight (9) FID: Flame Ionization Detector (10) gpm: Grams per mile (11) GVWR: Gross Vehicle Weight Rating (12) HC: Hydrocarbons (13) HDGT: Heavy-Duty Gasoline-powered Truck greater than 8500 pounds GVWR (14) hp: Horsepower (15) Hz: Cycles per Second (Hertz) (16) I/M: Inspection and Maintenance (17) IW: Inertia Weight (18) LDGV: Light-Duty Gasoline-powered Vehicle (19) LVW: Loaded Vehicle Weight: VCW + 300 pounds (20) mph: Miles per hour (21) NDIR: Non-Dispersive Infrared (22) NIST: National Institute for Standards and Technology (23) NO 2 : Nitrogen Dioxide (24) NO: Nitrogen Oxide (25) NO x : Oxides of Nitrogen (26) NVFEL: National Vehicle and Fuel Emissions Laboratory (27) Obmph: Observed dynamometer speed in mph of the loading roller, if rolls are not coupled (28) PLHP: Parasitic horsepower loss at the observed dynamometer speed in mph (29) ppm: parts per million by volume (30) ppmC: parts per million, carbon (31) psi: Pounds per square inch (32) RFP: Request for Proposal (33) RLHP Road Load Horsepower (34) rpm: revolutions per minute (35) SCFM: Standard cubic feet per minute (36) SPC: Statistical Process Control (37) SRM: Standard Reference Material (38) SSV: Subsonic venturi (39) TRLHP: Track Road-Load Horsepower (40) VCW: Vehicle Curb Weight: Actual vehicle weight with standard equipment and 100% fuel fill (41) WC: Pressure in inches of water column44 Appendix A

Guidance on the Use of Fast-Pass IM240 Standards45 Guidance on the Use of Fast-Pass IM240 Standards A fast-pass decision is made by measuring the vehicle's cumulative emissions of each pollutant in each second, and comparing them to cumulative emission fast-pass standards for each pollutant for the second of the test under consideration. In general, if the vehicle's cumulative emissions are below a given level for all pollutants the vehicle passes. Testing continues until decisions are made for each pollutant. Measurements of all constituents shall continue to be taken as long as the test continues, including those constituents for which a decision has already been made. These fast-pass standards are derived from an Arizona IM240 data set which included 3,718 tests. Fast-pass standards for each second represent the tenth lowest cumulative emission levels in that second obtained for vehicles failing the IM240 using the two-ways-to-pass criteria. Hence, vehicles that fall below this level are showing lower cumulative emissions at that point in the test than the cleanest vehicles failing the full test and therefore pass. Fast-pass determinati ons begin at second 30 of the IM240 cycle. Beginning at second 109, fast pass decisions for HC and CO are based upon analysis of cumulative emissions in phase 2, the portion of the test beginning at second 94, as well as emission levels accumulated from the beginning of the test (the "composite" test). Fast-pass standards are derived for phase 2 of the test as described above. Since the phase 2 standards for NO x are the same as the composite, the phase 2 NO x fast-pass standards are also the same as the composite.

Scores HC t = cumulative composite HC at time = t seconds
CO t = cumulative composite CO at time = t seconds NOx t = cumulative composite NOx at time = t seconds HC bt = cumulative Phase 2 HC at time = t seconds CO bt = cumulative Phase 2 CO at time = t seconds NOx bt = cumulative Phase 2 NOx at time = t seconds Cumulative composite scores represent the cumulative grams of emissions from t = 0 seconds Cumulative Phase 2 scores represent the cumulative grams of emissions from t = 109 seconds

Fast-Pass Standards HC pt = composite HC fast-pass standard at time = t seconds CO pt = composite CO fast-pass standard at time = t seconds NOx pt = composite NOx fast-pass standard for failing vehicles at time = t seconds HC pbt = Phase 2 HC fast-pass standard at time = t seconds CO pbt = Phase 2 CO fast-pass standard at time = t seconds NOx pbt = Phase 2 NOx fast-pass standard at time = t seconds

Fast-Pass Conditions For t > 30 seconds, the vehicle shall pass if:
HC t < HC pt

and CO t < CO pt , NOx t < NOx pt ; additionally, for t > 109 seconds, the vehicle shall pass if: HC bt < HC pbt and CO bt < CO pbt and NOx bt < NOx pbt or HC t < HC pt and CO bt < CO pbt and NOx bt < NOx pbt or HC t < HC pt and CO t < CO pt and NOx bt < NOx pbt or HC bt < HC pbt and CO t < CO pt and NOx bt <NOx pbt or HC bt < HC pbt and CO t < CO pt and NOx t < NOx pt or HC bt < HC pbt and CO bt < CO pbt and NOx t < NOx pt46 IM240 FAST-PASS EMISSION STANDARDS (grams)

Hydrocarbons Carbon Monoxide Oxides of Nitrogen Sec Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 0.80 0.50 1.25 0.75 2.00 1.25 15.0 12.0 20.0 16.0 30.0 24.0 2.0 2.5 3.0 30 0.124 n/a 0.247 n/a 0.407 n/a 0.693 n/a 1.502 n/a 3.804 n/a 0.167 0.262 0.419 31 0.126 n/a 0.253 n/a 0.415 n/a 0.773 n/a 1.546 n/a 3.985 n/a 0.177 0.275 0.425 32 0.129 n/a 0.258 n/a 0.423 n/a 0.837 n/a 1.568 n/a 4.215 n/a 0.188 0.301 0.431 33 0.135 n/a 0.263 n/a 0.436 n/a 0.851 n/a 1.582 n/a 4.440 n/a 0.214 0.317 0.449 34 0.140 n/a 0.268 n/a 0.451 n/a 0.853 n/a 1.593 n/a 4.579 n/a 0.232 0.327 0.476 35 0.146 n/a 0.277 n/a 0.464 n/a 0.857 n/a 1.602 n/a 4.688 n/a 0.240 0.330 0.497 36 0.150 n/a 0.283 n/a 0.468 n/a 0.900 n/a 1.621 n/a 4.749 n/a 0.243 0.332 0.515 37 0.153 n/a 0.293 n/a 0.475 n/a 0.960 n/a 1.631 n/a 4.783 n/a 0.245 0.334 0.516 38 0.156 n/a 0.297 n/a 0.487 n/a 1.034 n/a 1.702 n/a 4.813 n/a 0.246 0.336 0.519 39 0.160 n/a 0.298 n/a 0.506 n/a 1.070 n/a 1.784 n/a 4.876 n/a 0.246 0.337 0.527 40 0.165 n/a 0.313 n/a 0.530 n/a 1.076 n/a 1.879 n/a 5.104 n/a 0.250 0.354 0.542 41 0.169 n/a 0.320 n/a 0.549 n/a 1.083 n/a 2.162 n/a 5.217 n/a 0.260 0.366 0.560 42 0.172 n/a 0.327 n/a 0.569 n/a 1.102 n/a 2.307 n/a 5.383 n/a 0.277 0.410 0.598 43 0.173 n/a 0.342 n/a 0.588 n/a 1.111 n/a 2.343 n/a 5.571 n/a 0.311 0.414 0.616 44 0.177 n/a 0.360 n/a 0.609 n/a 1.114 n/a 2.376 n/a 5.888 n/a 0.328 0.438 0.645 45 0.197 n/a 0.376 n/a 0.621 n/a 1.157 n/a 2.406 n/a 6.199 n/a 0.343 0.477 0.670 46 0.200 n/a 0.389 n/a 0.636 n/a 1.344 n/a 2.433 n/a 6.245 n/a 0.359 0.506 0.691 47 0.208 n/a 0.408 n/a 0.649 n/a 1.482 n/a 2.458 n/a 6.318 n/a 0.373 0.518 0.716 48 0.221 n/a 0.423 n/a 0.666 n/a 1.530 n/a 2.483 n/a 6.418 n/a 0.383 0.522 0.735 49 0.232 n/a 0.434 n/a 0.679 n/a 1.542 n/a 2.774 n/a 6.540 n/a 0.385 0.526 0.765 50 0.235 n/a 0.444 n/a 0.696 n/a 1.553 n/a 2.844 n/a 6.690 n/a 0.400 0.554 0.802 51 0.238 n/a 0.454 n/a 0.712 n/a 1.571 n/a 2.900 n/a 6.875 n/a 0.410 0.574 0.836 52 0.240 n/a 0.465 n/a 0.727 n/a 1.595 n/a 2.936 n/a 7.029 n/a 0.434 0.587 0.868 53 0.242 n/a 0.472 n/a 0.745 n/a 1.633 n/a 3.133 n/a 7.129 n/a 0.464 0.601 0.890 54 0.246 n/a 0.478 n/a 0.760 n/a 1.685 n/a 3.304 n/a 7.359 n/a 0.472 0.615 0.918 55 0.249 n/a 0.485 n/a 0.776 n/a 1.689 n/a 3.407 n/a 7.722 n/a 0.480 0.629 0.936 56 0.252 n/a 0.493 n/a 0.797 n/a 1.693 n/a 3.456 n/a 8.017 n/a 0.491 0.643 0.947 57 0.261 n/a 0.500 n/a 0.814 n/a 1.700 n/a 3.480 n/a 8.249 n/a 0.500 0.667 0.958 58 0.271 n/a 0.505 n/a 0.826 n/a 1.723 n/a 3.518 n/a 8.425 n/a 0.506 0.678 0.970 59 0.276 n/a 0.514 n/a 0.837 n/a 1.852 n/a 3.560 n/a 8.563 n/a 0.509 0.683 0.982 60 0.278 n/a 0.537 n/a 0.849 n/a 1.872 n/a 3.593 n/a 8.686 n/a 0.512 0.686 0.994 61 0.280 n/a 0.540 n/a 0.862 n/a 1.872 n/a 3.628 n/a 8.804 n/a 0.516 0.693 1.019 62 0.282 n/a 0.543 n/a 0.872 n/a 1.872 n/a 3.641 n/a 8.916 n/a 0.519 0.699 1.042 63 0.283 n/a 0.546 n/a 0.887 n/a 1.900 n/a 3.655 n/a 9.025 n/a 0.523 0.703 1.049 64 0.284 n/a 0.551 n/a 0.895 n/a 1.917 n/a 3.680 n/a 9.138 n/a 0.529 0.707 1.058 65 0.285 n/a 0.559 n/a 0.903 n/a 1.944 n/a 3.700 n/a 9.250 n/a 0.533 0.711 1.062 66 0.286 n/a 0.567 n/a 0.925 n/a 2.000 n/a 3.728 n/a 9.354 n/a 0.535 0.716 1.064 67 0.288 n/a 0.575 n/a 0.933 n/a 2.060 n/a 3.857 n/a 9.457 n/a 0.540 0.721 1.070 68 0.291 n/a 0.588 n/a 0.945 n/a 2.064 n/a 3.894 n/a 9.575 n/a 0.551 0.726 1.077 69 0.294 n/a 0.595 n/a 0.959 n/a 2.076 n/a 3.943 n/a 9.728 n/a 0.563 0.742 1.085 70 0.296 n/a 0.601 n/a 0.970 n/a 2.104 n/a 3.983 n/a 9.938 n/a 0.575 0.759 1.092 71 0.298 n/a 0.606 n/a 0.980 n/a 2.117 n/a 4.009 n/a 10.140 n/a 0.588 0.773 1.101 72 0.300 n/a 0.610 n/a 0.988 n/a 2.125 n/a 4.023 n/a 10.222 n/a 0.600 0.784 1.111 73 0.302 n/a 0.617 n/a 0.997 n/a 2.130 n/a 4.023 n/a 10.261 n/a 0.603 0.790 1.121 74 0.304 n/a 0.631 n/a 1.022 n/a 2.138 n/a 4.053 n/a 10.278 n/a 0.604 0.794 1.13147 75 0.307 n/a 0.643 n/a 1.037 n/a 2.152 n/a 4.063 n/a 10.290 n/a 0.613 0.799 1.141 76 0.308 n/a 0.651 n/a 1.051 n/a 2.170 n/a 4.077 n/a 10.715 n/a 0.624 0.809 1.159 77 0.308 n/a 0.659 n/a 1.064 n/a 2.188 n/a 4.225 n/a 10.790 n/a 0.646 0.821 1.164 78 0.308 n/a 0.667 n/a 1.075 n/a 2.200 n/a 4.243 n/a 10.844 n/a 0.651 0.833 1.186 79 0.314 n/a 0.676 n/a 1.087 n/a 2.212 n/a 4.260 n/a 10.921 n/a 0.659 0.839 1.221 80 0.320 n/a 0.681 n/a 1.097 n/a 2.212 n/a 4.282 n/a 11.010 n/a 0.673 0.844 1.260 81 0.324 n/a 0.685 n/a 1.105 n/a 2.221 n/a 4.322 n/a 11.090 n/a 0.696 0.857 1.268 82 0.327 n/a 0.689 n/a 1.114 n/a 2.222 n/a 4.398 n/a 11.136 n/a 0.706 0.870 1.272 83 0.329 n/a 0.694 n/a 1.136 n/a 2.227 n/a 4.482 n/a 11.136 n/a 0.715 0.883 1.277 84 0.333 n/a 0.700 n/a 1.160 n/a 2.236 n/a 4.515 n/a 11.165 n/a 0.724 0.894 1.288 85 0.336 n/a 0.705 n/a 1.182 n/a 2.243 n/a 4.518 n/a 11.191 n/a 0.737 0.902 1.310 86 0.339 n/a 0.709 n/a 1.201 n/a 2.262 n/a 4.520 n/a 11.205 n/a 0.747 0.907 1.319 87 0.343 n/a 0.713 n/a 1.217 n/a 2.271 n/a 4.522 n/a 11.211 n/a 0.748 0.910 1.320 88 0.347 n/a 0.717 n/a 1.233 n/a 2.284 n/a 4.522 n/a 11.211 n/a 0.748 0.912 1.337 89 0.350 n/a 0.721 n/a 1.248 n/a 2.299 n/a 4.523 n/a 11.211 n/a 0.748 0.913 1.348 90 0.356 n/a 0.724 n/a 1.262 n/a 2.308 n/a 4.526 n/a 11.211 n/a 0.748 0.914 1.361 91 0.358 n/a 0.727 n/a 1.271 n/a 2.326 n/a 4.527 n/a 11.220 n/a 0.748 0.915 1.366 92 0.360 n/a 0.729 n/a 1.279 n/a 2.330 n/a 4.527 n/a 11.294 n/a 0.748 0.916 1.369 93 0.363 n/a 0.731 n/a 1.287 n/a 2.331 n/a 4.528 n/a 11.332 n/a 0.748 0.917 1.373 94 0.367 n/a 0.734 n/a 1.295 n/a 2.344 n/a 4.528 n/a 11.355 n/a 0.748 0.918 1.375 95 0.370 n/a 0.740 n/a 1.302 n/a 2.347 n/a 4.528 n/a 11.383 n/a 0.748 0.919 1.377 96 0.372 n/a 0.748 n/a 1.309 n/a 2.355 n/a 4.529 n/a 11.410 n/a 0.748 0.920 1.379 97 0.376 n/a 0.759 n/a 1.316 n/a 2.395 n/a 4.575 n/a 11.433 n/a 0.748 0.921 1.381 98 0.388 n/a 0.771 n/a 1.325 n/a 2.451 n/a 4.703 n/a 11.516 n/a 0.748 0.922 1.383 99 0.396 n/a 0.783 n/a 1.339 n/a 2.508 n/a 4.805 n/a 11.820 n/a 0.751 0.924 1.385 100 0.405 n/a 0.793 n/a 1.356 n/a 2.590 n/a 4.886 n/a 12.104 n/a 0.764 0.929 1.399 101 0.410 n/a 0.810 n/a 1.365 n/a 2.660 n/a 4.957 n/a 12.344 n/a 0.789 0.941 1.405 102 0.411 n/a 0.823 n/a 1.378 n/a 2.749 n/a 5.104 n/a 12.781 n/a 0.822 0.970 1.466 103 0.412 n/a 0.836 n/a 1.397 n/a 2.913 n/a 5.340 n/a 13.472 n/a 0.867 1.027 1.485 104 0.413 n/a 0.853 n/a 1.420 n/a 3.162 n/a 5.496 n/a 14.405 n/a 0.905 1.093 1.546 105 0.421 n/a 0.871 n/a 1.445 n/a 3.170 n/a 5.625 n/a 14.808 n/a 0.925 1.155 1.623 106 0.428 n/a 0.887 n/a 1.470 n/a 3.197 n/a 5.815 n/a 14.965 n/a 0.955 1.234 1.699 107 0.430 n/a 0.899 n/a 1.491 n/a 3.288 n/a 6.473 n/a 15.121 n/a 0.985 1.275 1.760 108 0.455 n/a 0.931 n/a 1.506 n/a 3.419 n/a 7.037 n/a 15.372 n/a 0.993 1.305 1.788 109 0.459 0.015 0.947 0.040 1.517 0.151 3.587 0.168 7.419 0.246 15.530 1.113 0.995 1.320 1.798 110 0.462 0.017 0.957 0.047 1.528 0.159 3.595 0.173 7.643 0.257 15.687 1.213 0.996 1.332 1.842 111 0.464 0.021 0.965 0.052 1.542 0.172 3.640 0.237 7.759 0.286 16.018 1.344 1.010 1.346 1.864 112 0.466 0.024 0.971 0.056 1.559 0.186 3.740 0.266 7.824 0.379 16.527 1.399 1.028 1.358 1.888 113 0.468 0.024 0.977 0.061 1.578 0.199 3.868 0.280 7.889 0.425 16.810 1.520 1.034 1.378 1.905 114 0.471 0.025 0.983 0.064 1.594 0.207 3.877 0.291 7.960 0.457 16.961 1.640 1.044 1.406 1.920 115 0.488 0.026 1.003 0.072 1.605 0.216 3.934 0.314 8.024 0.477 17.120 1.684 1.059 1.426 1.926 116 0.513 0.029 1.030 0.081 1.615 0.229 4.015 0.331 8.076 0.494 17.135 1.693 1.075 1.438 1.939 117 0.538 0.032 1.041 0.082 1.625 0.235 4.061 0.345 8.111 0.504 17.249 1.786 1.080 1.448 1.958 118 0.561 0.035 1.050 0.083 1.642 0.240 4.063 0.350 8.130 0.512 17.451 2.007 1.080 1.460 1.972 119 0.577 0.035 1.052 0.092 1.670 0.245 4.079 0.356 8.148 0.519 17.509 2.084 1.081 1.462 1.981 120 0.580 0.036 1.055 0.094 1.694 0.261 4.140 0.367 8.211 0.529 17.605 2.179 1.091 1.467 1.987 121 0.586 0.038 1.061 0.097 1.705 0.267 4.185 0.388 8.478 0.529 17.734 2.264 1.096 1.476 1.991 122 0.594 0.040 1.071 0.100 1.717 0.277 4.199 0.407 8.548 0.530 18.049 2.328 1.111 1.494 1.996 123 0.603 0.041 1.081 0.103 1.732 0.287 4.205 0.463 8.561 0.531 18.447 2.375 1.122 1.505 2.012 124 0.610 0.042 1.091 0.106 1.747 0.298 4.212 0.480 8.568 0.532 18.592 2.437 1.135 1.517 2.040 125 0.615 0.042 1.102 0.108 1.763 0.308 4.232 0.506 8.572 0.533 18.657 2.543 1.138 1.546 2.060 126 0.624 0.042 1.110 0.110 1.779 0.316 4.298 0.518 8.584 0.548 18.796 2.593 1.139 1.569 2.069 127 0.628 0.045 1.116 0.112 1.795 0.322 4.344 0.522 8.592 0.610 18.952 2.641 1.139 1.586 2.09248 128 0.632 0.046 1.121 0.114 1.810 0.329 4.361 0.525 8.596 0.614 19.137 2.663 1.139 1.596 2.114 129 0.637 0.046 1.125 0.116 1.823 0.338 4.366 0.528 8.597 0.622 19.329 2.672 1.139 1.603 2.132 130 0.641 0.049 1.128 0.118 1.835 0.346 4.369 0.530 8.601 0.631 19.519 2.676 1.139 1.605 2.144 131 0.643 0.050 1.130 0.120 1.845 0.354 4.372 0.530 8.605 0.640 19.707 2.683 1.139 1.606 2.152 132 0.644 0.052 1.132 0.122 1.854 0.356 4.435 0.534 8.608 0.646 19.882 2.817 1.139 1.607 2.157 133 0.645 0.054 1.134 0.123 1.862 0.357 4.523 0.550 8.626 0.650 19.905 2.992 1.139 1.607 2.160 134 0.647 0.054 1.135 0.124 1.870 0.359 4.524 0.554 8.650 0.652 20.049 3.111 1.139 1.608 2.163 135 0.651 0.054 1.143 0.127 1.883 0.362 4.525 0.590 8.660 0.738 20.460 3.234 1.139 1.614 2.165 136 0.658 0.055 1.147 0.130 1.888 0.364 4.531 0.616 8.767 0.754 20.746 3.304 1.160 1.616 2.168 137 0.663 0.055 1.156 0.134 1.896 0.368 4.534 0.639 9.029 0.780 21.068 3.310 1.174 1.631 2.171 138 0.666 0.056 1.163 0.139 1.911 0.378 4.542 0.653 9.238 0.795 21.380 3.320 1.183 1.643 2.186 139 0.668 0.059 1.186 0.146 1.928 0.391 4.553 0.662 9.389 0.804 21.748 3.354 1.197 1.656 2.235 140 0.670 0.061 1.253 0.149 1.949 0.402 4.554 0.683 9.493 0.810 22.046 3.436 1.223 1.673 2.298 141 0.672 0.061 1.262 0.151 1.969 0.408 4.554 0.696 9.583 0.815 22.348 3.443 1.255 1.703 2.333 142 0.675 0.061 1.271 0.153 1.982 0.422 4.554 0.708 9.626 0.818 22.397 3.452 1.272 1.739 2.373 143 0.678 0.063 1.277 0.155 1.999 0.428 4.554 0.721 9.669 0.821 22.407 3.490 1.286 1.767 2.406 144 0.681 0.064 1.283 0.157 2.011 0.432 4.554 0.739 9.716 0.825 22.417 3.552 1.304 1.774 2.416 145 0.684 0.065 1.291 0.162 2.022 0.434 4.554 0.742 9.763 0.840 22.922 3.588 1.307 1.785 2.420 146 0.686 0.066 1.294 0.164 2.035 0.439 4.554 0.743 9.809 0.847 22.951 3.600 1.312 1.806 2.424 147 0.688 0.067 1.296 0.166 2.043 0.450 4.554 0.745 9.852 0.855 22.976 3.616 1.317 1.830 2.435 148 0.690 0.068 1.298 0.168 2.049 0.460 4.554 0.748 9.885 0.865 23.017 3.627 1.321 1.844 2.455 149 0.692 0.069 1.303 0.169 2.063 0.467 4.554 0.751 9.932 0.874 23.073 3.636 1.325 1.845 2.471 150 0.694 0.070 1.316 0.170 2.085 0.472 4.554 0.762 9.986 0.891 23.161 3.676 1.328 1.846 2.484 151 0.696 0.071 1.330 0.171 2.104 0.480 4.556 0.789 10.039 0.914 23.218 3.882 1.332 1.852 2.495 152 0.698 0.072 1.342 0.172 2.117 0.491 4.556 0.790 10.072 0.929 23.253 4.011 1.338 1.868 2.509 153 0.700 0.073 1.348 0.173 2.127 0.503 4.565 0.794 10.090 0.937 23.337 4.047 1.344 1.877 2.522 154 0.702 0.073 1.353 0.175 2.138 0.505 4.612 0.799 10.105 0.942 23.425 4.067 1.350 1.879 2.533 155 0.704 0.074 1.362 0.178 2.152 0.515 4.834 0.805 10.146 0.949 23.534 4.081 1.357 1.886 2.541 156 0.706 0.077 1.365 0.180 2.168 0.522 5.702 0.842 10.245 1.375 23.652 4.116 1.365 1.900 2.552 157 0.708 0.079 1.366 0.189 2.186 0.527 5.841 0.990 10.397 1.576 23.739 4.251 1.379 1.910 2.589 158 0.710 0.082 1.373 0.198 2.205 0.537 6.170 1.038 10.923 1.943 24.606 5.099 1.414 1.936 2.631 159 0.712 0.082 1.397 0.203 2.224 0.549 6.670 1.357 11.970 2.820 25.615 5.383 1.466 1.954 2.704 160 0.716 0.086 1.423 0.207 2.242 0.568 7.425 1.455 13.421 3.281 26.073 6.362 1.514 1.986 2.758 161 0.750 0.095 1.440 0.214 2.268 0.586 8.379 1.546 15.289 3.483 28.496 7.926 1.559 2.050 2.802 162 0.784 0.107 1.452 0.221 2.308 0.610 9.648 1.824 15.912 3.620 29.772 8.429 1.591 2.131 2.904 163 0.805 0.115 1.465 0.229 2.352 0.648 10.918 2.746 16.530 4.168 31.056 9.201 1.641 2.235 2.960 164 0.840 0.122 1.509 0.247 2.406 0.677 12.157 3.073 17.622 4.338 33.351 10.825 1.719 2.320 3.027 165 0.853 0.127 1.533 0.274 2.421 0.699 12.731 3.633 18.366 4.682 34.890 12.291 1.777 2.395 3.127 166 0.874 0.159 1.555 0.309 2.435 0.720 12.831 4.505 19.869 5.633 35.937 13.366 1.832 2.488 3.187 167 0.903 0.186 1.576 0.318 2.470 0.738 12.892 4.952 20.711 6.137 37.012 14.428 1.919 2.563 3.306 168 0.910 0.189 1.598 0.322 2.501 0.767 12.932 5.254 22.319 6.853 37.892 15.318 1.972 2.645 3.384 169 0.914 0.200 1.618 0.333 2.537 0.828 13.702 5.730 23.751 7.136 39.028 15.699 2.013 2.746 3.467 170 0.916 0.220 1.636 0.343 2.571 0.855 14.139 6.051 24.842 7.320 40.406 16.073 2.100 2.778 3.565 171 0.919 0.236 1.666 0.356 2.625 0.869 14.964 6.333 25.410 7.685 41.379 16.475 2.200 2.792 3.640 172 0.931 0.247 1.685 0.385 2.657 0.885 15.704 6.490 25.798 8.052 42.033 17.158 2.251 2.810 3.718 173 0.948 0.257 1.726 0.409 2.683 0.900 16.253 6.796 26.122 8.344 42.432 17.532 2.270 2.847 3.781 174 0.983 0.267 1.742 0.433 2.701 0.941 16.907 7.205 26.353 8.602 42.742 17.965 2.301 2.874 3.827 175 1.018 0.283 1.756 0.453 2.717 0.979 17.655 8.151 26.638 8.898 43.399 18.242 2.318 2.905 3.852 176 1.027 0.295 1.769 0.463 2.732 1.002 18.020 8.230 27.219 9.251 43.895 18.283 2.335 2.950 3.903 177 1.035 0.312 1.784 0.507 2.756 1.025 18.349 8.584 27.279 10.253 44.227 18.480 2.349 3.001 3.930 178 1.051 0.318 1.802 0.523 2.781 1.047 18.671 8.800 27.320 10.828 44.926 19.576 2.387 3.047 3.970 179 1.074 0.323 1.822 0.528 2.811 1.065 18.972 8.847 27.352 10.933 45.256 20.015 2.423 3.104 4.015 180 1.084 0.337 1.843 0.541 2.853 1.089 19.228 8.913 27.822 11.060 45.553 20.203 2.462 3.173 4.07449 181 1.099 0.345 1.864 0.549 2.898 1.109 20.123 9.122 28.763 11.188 45.753 20.433 2.503 3.238 4.159 182 1.121 0.350 1.884 0.559 2.946 1.133 20.405 9.532 29.402 11.345 46.210 21.025 2.545 3.302 4.230 183 1.132 0.359 1.896 0.571 2.988 1.158 20.754 10.256 29.971 11.733 47.017 21.882 2.586 3.372 4.286 184 1.152 0.387 1.915 0.584 3.023 1.184 21.684 10.862 30.276 12.598 48.185 22.204 2.627 3.452 4.334 185 1.161 0.398 1.940 0.598 3.057 1.209 21.955 10.996 30.988 12.953 48.741 22.859 2.673 3.545 4.388 186 1.168 0.400 1.958 0.613 3.076 1.222 22.650 11.206 31.095 13.213 49.462 23.533 2.749 3.648 4.447 187 1.175 0.402 1.972 0.624 3.101 1.231 22.989 11.514 31.314 14.131 50.313 24.281 2.804 3.701 4.505 188 1.181 0.405 1.985 0.629 3.120 1.239 23.535 11.894 31.833 14.839 51.285 25.078 2.851 3.759 4.561 189 1.188 0.418 1.991 0.629 3.136 1.254 23.876 12.019 32.239 15.137 52.076 25.276 2.894 3.821 4.625 190 1.203 0.429 1.993 0.638 3.151 1.278 24.018 12.170 32.547 15.138 52.857 25.578 2.931 3.870 4.696 191 1.219 0.442 1.995 0.648 3.163 1.300 24.464 12.517 32.855 15.141 52.876 25.859 2.971 3.892 4.731 192 1.233 0.457 2.001 0.659 3.209 1.313 24.685 12.598 33.153 15.595 53.067 25.985 3.020 3.914 4.780 193 1.251 0.473 2.015 0.663 3.223 1.324 24.931 12.625 33.444 15.658 53.777 26.153 3.077 3.955 4.837 194 1.255 0.487 2.031 0.671 3.237 1.340 25.188 12.653 33.482 15.704 54.242 26.582 3.132 3.997 4.876 195 1.258 0.501 2.047 0.681 3.263 1.367 25.468 12.777 33.516 15.729 54.489 27.067 3.185 4.035 4.928 196 1.265 0.510 2.063 0.693 3.302 1.387 25.627 12.906 33.549 16.058 54.601 27.456 3.219 4.089 4.972 197 1.280 0.512 2.079 0.709 3.338 1.402 25.746 12.989 33.653 16.987 54.912 27.805 3.268 4.146 5.025 198 1.293 0.514 2.094 0.725 3.372 1.417 25.850 13.060 33.973 17.064 55.588 28.070 3.299 4.206 5.104 199 1.301 0.516 2.109 0.740 3.390 1.432 25.974 13.165 34.159 17.073 56.266 28.590 3.350 4.243 5.189 200 1.313 0.518 2.122 0.754 3.428 1.446 26.141 13.242 34.191 17.153 56.617 28.914 3.406 4.295 5.275 201 1.324 0.527 2.130 0.767 3.470 1.460 26.225 13.412 34.250 17.332 56.863 29.063 3.466 4.351 5.336 202 1.332 0.540 2.137 0.775 3.493 1.477 26.338 13.662 34.469 17.406 57.204 29.502 3.497 4.398 5.366 203 1.341 0.547 2.157 0.787 3.509 1.492 26.547 13.773 34.716 17.641 57.371 29.697 3.514 4.410 5.387 204 1.357 0.553 2.172 0.795 3.522 1.501 26.818 13.942 34.969 17.922 57.487 29.713 3.517 4.419 5.427 205 1.375 0.559 2.194 0.803 3.533 1.510 27.052 14.090 35.144 18.484 57.728 29.783 3.519 4.426 5.444 206 1.392 0.563 2.222 0.854 3.550 1.522 27.393 14.224 35.418 18.553 58.097 29.942 3.523 4.429 5.447 207 1.408 0.567 2.245 0.859 3.578 1.561 27.501 14.426 35.766 18.658 58.572 30.284 3.545 4.453 5.477 208 1.422 0.571 2.268 0.872 3.607 1.585 27.632 14.498 35.949 18.953 59.024 30.755 3.570 4.486 5.520 209 1.433 0.575 2.279 0.892 3.630 1.597 27.803 14.776 36.010 19.266 59.321 31.287 3.600 4.542 5.560 210 1.443 0.579 2.288 0.896 3.658 1.607 27.953 14.907 36.548 19.309 59.715 31.549 3.619 4.598 5.603 211 1.453 0.595 2.301 0.903 3.701 1.627 28.205 14.916 37.179 19.731 60.045 31.820 3.639 4.638 5.657 212 1.463 0.605 2.316 0.924 3.745 1.645 28.543 15.014 37.651 19.902 60.453 32.250 3.686 4.715 5.698 213 1.468 0.614 2.332 0.938 3.778 1.656 28.997 15.221 38.041 20.012 60.935 32.546 3.732 4.774 5.762 214 1.470 0.622 2.345 0.941 3.814 1.663 29.000 15.472 38.591 20.260 61.307 32.808 3.791 4.829 5.827 215 1.474 0.627 2.354 0.951 3.825 1.669 29.005 15.555 38.852 20.739 61.666 33.060 3.833 4.872 5.849 216 1.478 0.638 2.362 0.966 3.835 1.674 29.081 15.652 38.861 21.346 62.148 33.204 3.890 4.931 5.884 217 1.481 0.643 2.368 0.979 3.844 1.685 29.281 15.969 38.926 21.810 62.532 33.341 3.932 4.960 5.908 218 1.484 0.643 2.376 0.980 3.853 1.700 29.483 16.028 39.194 22.001 62.546 33.414 3.960 4.963 5.921 219 1.487 0.645 2.384 0.981 3.864 1.704 29.734 16.375 39.474 22.290 62.559 33.514 3.997 4.965 5.931 220 1.490 0.651 2.391 1.005 3.874 1.706 29.803 16.487 39.668 22.324 62.570 33.640 4.013 4.968 5.939 221 1.493 0.655 2.395 1.016 3.891 1.709 29.821 16.524 39.781 22.343 62.846 33.692 4.035 4.971 5.947 222 1.504 0.663 2.400 1.022 3.928 1.711 29.847 16.578 39.890 22.522 63.097 33.711 4.038 4.974 5.952 223 1.522 0.671 2.405 1.028 3.966 1.714 29.862 16.684 39.954 22.661 63.150 33.733 4.050 4.977 5.955 224 1.547 0.675 2.409 1.035 4.008 1.718 29.873 16.755 39.984 22.666 63.150 33.770 4.066 4.979 5.957 225 1.549 0.684 2.413 1.041 4.010 1.721 30.008 16.770 39.989 22.667 63.150 33.796 4.070 4.980 5.959 226 1.562 0.694 2.415 1.045 4.012 1.723 30.126 16.805 39.990 22.668 63.150 33.810 4.072 4.981 5.961 227 1.574 0.701 2.417 1.051 4.016 1.726 30.127 16.865 39.990 22.669 63.150 33.821 4.072 4.982 5.963 228 1.579 0.702 2.419 1.055 4.019 1.729 30.127 16.960 39.990 22.670 63.150 33.839 4.073 4.983 5.966 229 1.584 0.708 2.420 1.059 4.057 1.731 30.208 16.960 39.991 22.671 63.150 33.865 4.073 4.984 5.971 230 1.589 0.708 2.421 1.062 4.065 1.733 30.314 16.962 40.012 22.671 63.150 33.894 4.073 4.985 5.977 231 1.590 0.709 2.423 1.063 4.071 1.735 30.323 16.988 40.061 22.672 63.150 33.918 4.073 4.986 5.984 232 1.596 0.710 2.425 1.063 4.073 1.743 30.325 17.072 40.116 22.673 63.150 33.944 4.074 4.987 5.990 233 1.598 0.710 2.427 1.063 4.075 1.749 30.368 17.094 40.249 22.673 63.150 33.985 4.074 4.988 5.99750 234 1.604 0.711 2.429 1.064 4.077 1.753 30.411 17.184 40.253 22.673 63.153 34.014 4.075 4.989 6.004 235 1.610 0.712 2.430 1.064 4.079 1.757 30.416 17.187 40.290 22.674 63.159 34.032 4.075 4.990 6.012 236 1.612 0.712 2.431 1.066 4.081 1.762 30.428 17.188 40.385 22.675 63.173 34.051 4.076 4.991 6.024 237 1.613 0.712 2.432 1.069 4.083 1.767 30.430 17.189 40.488 22.675 63.193 34.067 4.076 4.992 6.037 238 1.614 0.713 2.433 1.072 4.084 1.772 30.452 17.241 40.720 22.675 63.214 34.079 4.076 4.993 6.049 239 1.615 0.716 2.434 1.075 4.085 1.776 30.488 17.370 40.763 22.677 63.233 34.085 4.076 4.994 6.06051 Appendix B Alternative Fast-Pass IM240 Standards52 Alternative Fast-Pass IM240 Standards Corresponding to Composite Start-up Emission Standards in §85.2205(a)(2)(i) and §85.2205(a)(2)(ii) Light Duty Vehicles
Low Altitude Low Altitude Low Altitude High Altitude Sec 1981-1982 1983-1990 1991-1995 1982 HC CO NOx HC CO NOx HC CO NOx HC CO NOx 30 0.330 4.189 0.250 0.330 1.941 0.251 0.174 1.307 0.222 0.330 7.391 0.250 31 0.342 4.278 0.267 0.342 1.983 0.268 0.179 1.329 0.246 0.342 7.667 0.267 32 0.353 4.366 0.283 0.353 2.025 0.285 0.184 1.350 0.270 0.353 7.944 0.283 33 0.364 4.455 0.300 0.365 2.067 0.302 0.189 1.372 0.294 0.364 8.220 0.300 34 0.375 4.544 0.316 0.376 2.108 0.320 0.194 1.394 0.318 0.375 8.497 0.316 35 0.386 4.633 0.333 0.388 2.150 0.337 0.199 1.416 0.342 0.386 8.773 0.333 36 0.398 4.728 0.336 0.399 2.230 0.339 0.201 1.453 0.345 0.398 9.011 0.336 37 0.409 4.823 0.339 0.410 2.310 0.342 0.203 1.490 0.348 0.409 9.249 0.339 38 0.420 4.917 0.342 0.420 2.390 0.344 0.205 1.527 0.350 0.420 9.488 0.342 39 0.431 5.012 0.345 0.431 2.471 0.347 0.207 1.565 0.353 0.431 9.726 0.345 40 0.443 5.107 0.348 0.442 2.551 0.349 0.209 1.602 0.356 0.443 9.964 0.348 41 0.458 5.429 0.371 0.458 2.738 0.373 0.214 1.642 0.373 0.458 10.527 0.371 42 0.474 5.751 0.394 0.473 2.926 0.397 0.219 1.682 0.390 0.474 11.090 0.394 43 0.489 6.073 0.418 0.489 3.114 0.422 0.224 1.722 0.407 0.489 11.652 0.418 44 0.505 6.395 0.441 0.505 3.302 0.446 0.228 1.763 0.425 0.505 12.215 0.441 45 0.521 6.717 0.465 0.520 3.489 0.470 0.233 1.803 0.442 0.521 12.778 0.465 46 0.535 6.985 0.480 0.536 3.589 0.486 0.238 1.867 0.465 0.535 13.265 0.480 47 0.550 7.254 0.496 0.552 3.688 0.501 0.244 1.932 0.487 0.550 13.751 0.496 48 0.565 7.522 0.512 0.568 3.787 0.517 0.250 1.997 0.510 0.565 14.238 0.512 49 0.580 7.791 0.527 0.584 3.887 0.533 0.255 2.061 0.533 0.580 14.724 0.527 50 0.594 8.060 0.543 0.600 3.986 0.549 0.261 2.126 0.555 0.594 15.211 0.543 51 0.611 8.511 0.567 0.617 4.029 0.571 0.268 2.152 0.573 0.611 15.550 0.567 52 0.628 8.962 0.590 0.633 4.072 0.594 0.275 2.179 0.590 0.628 15.889 0.590 53 0.644 9.413 0.613 0.649 4.115 0.616 0.282 2.205 0.608 0.644 16.228 0.613 54 0.661 9.865 0.637 0.665 4.157 0.638 0.290 2.232 0.625 0.661 16.567 0.637 55 0.678 10.316 0.660 0.681 4.200 0.661 0.297 2.258 0.643 0.678 16.907 0.660 56 0.691 10.818 0.675 0.696 4.263 0.676 0.302 2.348 0.654 0.691 17.199 0.675 57 0.705 11.320 0.689 0.710 4.326 0.691 0.306 2.437 0.666 0.705 17.492 0.689 58 0.718 11.822 0.703 0.725 4.388 0.707 0.311 2.526 0.677 0.718 17.785 0.703 59 0.731 12.325 0.718 0.740 4.451 0.722 0.316 2.616 0.688 0.731 18.078 0.718 60 0.745 12.827 0.732 0.754 4.514 0.737 0.320 2.705 0.700 0.745 18.371 0.732 61 0.758 13.228 0.743 0.767 4.589 0.748 0.323 2.726 0.707 0.758 18.609 0.743 62 0.772 13.629 0.754 0.780 4.664 0.758 0.326 2.746 0.714 0.772 18.847 0.754 63 0.786 14.029 0.764 0.794 4.740 0.769 0.329 2.767 0.722 0.786 19.085 0.764 64 0.799 14.430 0.775 0.807 4.815 0.780 0.332 2.787 0.729 0.799 19.323 0.775 65 0.813 14.831 0.786 0.820 4.891 0.790 0.335 2.808 0.736 0.813 19.562 0.786 66 0.827 15.046 0.794 0.833 4.945 0.799 0.340 2.812 0.742 0.827 19.887 0.794 67 0.841 15.261 0.803 0.846 4.999 0.808 0.345 2.816 0.747 0.841 20.213 0.80353 68 0.855 15.476 0.811 0.859 5.053 0.817 0.350 2.820 0.753 0.855 20.539 0.811 69 0.869 15.692 0.820 0.872 5.107 0.826 0.355 2.825 0.758 0.869 20.865 0.820 70 0.883 15.907 0.828 0.885 5.162 0.835 0.360 2.829 0.764 0.883 21.191 0.828 71 0.894 16.118 0.838 0.896 5.226 0.846 0.364 2.847 0.783 0.894 21.396 0.838 72 0.905 16.330 0.848 0.906 5.291 0.857 0.367 2.865 0.802 0.905 21.602 0.848 73 0.917 16.542 0.858 0.917 5.356 0.868 0.371 2.884 0.822 0.917 21.808 0.858 74 0.928 16.753 0.868 0.928 5.421 0.878 0.375 2.902 0.841 0.928 22.013 0.868 75 0.939 16.965 0.878 0.939 5.486 0.889 0.378 2.921 0.860 0.939 22.219 0.878 76 0.953 17.199 0.891 0.952 5.553 0.900 0.387 2.982 0.874 0.953 22.685 0.891 77 0.967 17.432 0.904 0.965 5.620 0.911 0.396 3.044 0.888 0.967 23.151 0.904 78 0.981 17.666 0.917 0.978 5.687 0.922 0.405 3.106 0.902 0.981 23.617 0.917 79 0.994 17.900 0.930 0.991 5.754 0.933 0.414 3.167 0.916 0.994 24.083 0.930 80 1.008 18.133 0.944 1.004 5.821 0.944 0.423 3.229 0.930 1.008 24.549 0.944 81 1.019 18.182 0.951 1.015 5.842 0.951 0.428 3.240 0.945 1.019 24.570 0.951 82 1.031 18.231 0.958 1.026 5.863 0.959 0.432 3.250 0.959 1.031 24.591 0.958 83 1.042 18.280 0.965 1.037 5.883 0.966 0.437 3.261 0.973 1.042 24.612 0.965 84 1.053 18.329 0.972 1.048 5.904 0.973 0.441 3.271 0.987 1.053 24.633 0.972 85 1.065 18.378 0.979 1.059 5.925 0.980 0.445 3.281 1.002 1.065 24.654 0.979 86 1.072 18.393 0.980 1.067 5.970 0.981 0.448 3.290 1.003 1.072 24.666 0.980 87 1.079 18.408 0.981 1.075 6.015 0.982 0.452 3.298 1.004 1.079 24.678 0.981 88 1.086 18.423 0.982 1.083 6.060 0.982 0.455 3.306 1.005 1.086 24.690 0.982 89 1.093 18.438 0.983 1.091 6.105 0.983 0.458 3.315 1.006 1.093 24.703 0.983 90 1.099 18.453 0.983 1.099 6.151 0.984 0.462 3.323 1.007 1.099 24.715 0.983 91 1.107 18.467 0.984 1.106 6.185 0.985 0.463 3.360 1.008 1.107 24.737 0.984 92 1.114 18.481 0.985 1.114 6.219 0.986 0.464 3.397 1.008 1.114 24.758 0.985 93 1.121 18.495 0.985 1.122 6.253 0.986 0.465 3.434 1.009 1.121 24.780 0.985 94 1.128 18.509 0.986 1.129 6.287 0.987 0.466 3.470 1.009 1.128 24.801 0.986 95 1.135 18.523 0.986 1.137 6.321 0.988 0.468 3.507 1.010 1.135 24.823 0.986 96 1.149 18.681 0.992 1.150 6.489 0.993 0.472 3.536 1.011 1.149 25.193 0.992 97 1.162 18.840 0.997 1.163 6.657 0.999 0.477 3.565 1.012 1.162 25.563 0.997 98 1.176 18.998 1.002 1.176 6.825 1.004 0.481 3.594 1.013 1.176 25.933 1.002 99 1.189 19.157 1.008 1.189 6.992 1.009 0.486 3.623 1.014 1.189 26.303 1.008 100 1.203 19.315 1.013 1.202 7.160 1.014 0.490 3.651 1.015 1.203 26.672 1.013 101 1.223 20.090 1.049 1.224 7.269 1.049 0.499 3.685 1.042 1.223 27.821 1.049 102 1.244 20.864 1.085 1.245 7.378 1.084 0.509 3.719 1.069 1.244 28.969 1.085 103 1.264 21.639 1.121 1.266 7.487 1.119 0.518 3.753 1.097 1.264 30.117 1.121 104 1.285 22.414 1.157 1.287 7.596 1.154 0.527 3.787 1.124 1.285 31.265 1.157 105 1.305 23.189 1.193 1.309 7.705 1.189 0.537 3.821 1.151 1.305 32.414 1.193 106 1.319 23.461 1.224 1.323 7.835 1.215 0.541 3.842 1.194 1.319 33.103 1.224 107 1.333 23.733 1.255 1.338 7.965 1.241 0.545 3.863 1.237 1.333 33.792 1.255 108 1.346 24.006 1.286 1.352 8.095 1.267 0.548 3.884 1.280 1.346 34.481 1.286 109 1.360 24.278 1.317 1.367 8.225 1.293 0.552 3.904 1.323 1.360 35.170 1.317 110 1.374 24.550 1.348 1.382 8.355 1.319 0.556 3.925 1.366 1.374 35.859 1.348 111 1.385 24.846 1.356 1.394 8.414 1.327 0.562 3.931 1.368 1.385 36.177 1.356 112 1.396 25.141 1.363 1.406 8.472 1.336 0.568 3.937 1.371 1.396 36.495 1.36354 113 1.407 25.437 1.371 1.418 8.531 1.345 0.574 3.943 1.374 1.407 36.813 1.371 114 1.417 25.732 1.378 1.430 8.590 1.354 0.580 3.949 1.377 1.417 37.132 1.378 115 1.428 26.028 1.386 1.442 8.649 1.363 0.586 3.956 1.380 1.428 37.450 1.386 116 1.437 26.045 1.388 1.451 8.735 1.364 0.590 3.975 1.380 1.437 37.554 1.388 117 1.446 26.062 1.389 1.460 8.821 1.365 0.593 3.995 1.381 1.446 37.658 1.389 118 1.455 26.079 1.391 1.469 8.907 1.366 0.597 4.015 1.382 1.455 37.761 1.391 119 1.464 26.096 1.393 1.479 8.992 1.368 0.600 4.035 1.383 1.464 37.865 1.393 120 1.472 26.114 1.394 1.488 9.078 1.369 0.604 4.055 1.383 1.472 37.969 1.394 121 1.488 26.293 1.408 1.501 9.152 1.385 0.610 4.152 1.400 1.488 38.310 1.408 122 1.503 26.472 1.422 1.514 9.227 1.401 0.615 4.250 1.417 1.503 38.650 1.422 123 1.518 26.651 1.435 1.527 9.301 1.417 0.621 4.348 1.433 1.518 38.990 1.435 124 1.534 26.830 1.449 1.540 9.375 1.434 0.627 4.445 1.450 1.534 39.330 1.449 125 1.549 27.010 1.463 1.553 9.449 1.450 0.632 4.543 1.466 1.549 39.671 1.463 126 1.559 27.151 1.471 1.563 9.519 1.458 0.636 4.567 1.470 1.559 39.865 1.471 127 1.569 27.292 1.479 1.572 9.590 1.467 0.639 4.592 1.473 1.569 40.059 1.479 128 1.579 27.433 1.487 1.582 9.661 1.475 0.642 4.617 1.476 1.579 40.254 1.487 129 1.590 27.575 1.495 1.592 9.731 1.484 0.645 4.641 1.479 1.590 40.448 1.495 130 1.600 27.716 1.502 1.601 9.802 1.492 0.648 4.666 1.482 1.600 40.642 1.502 131 1.612 27.878 1.506 1.615 9.849 1.496 0.653 4.685 1.483 1.612 40.790 1.506 132 1.624 28.040 1.509 1.628 9.895 1.500 0.657 4.704 1.485 1.624 40.937 1.509 133 1.635 28.202 1.512 1.642 9.942 1.504 0.661 4.724 1.486 1.635 41.084 1.512 134 1.647 28.365 1.515 1.655 9.989 1.508 0.666 4.743 1.488 1.647 41.231 1.515 135 1.659 28.527 1.519 1.669 10.035 1.512 0.670 4.762 1.489 1.659 41.379 1.519 136 1.676 28.833 1.542 1.685 10.104 1.534 0.678 4.785 1.507 1.676 42.023 1.542 137 1.693 29.140 1.566 1.700 10.173 1.557 0.685 4.807 1.524 1.693 42.668 1.566 138 1.709 29.446 1.589 1.716 10.241 1.580 0.693 4.830 1.541 1.709 43.312 1.589 139 1.726 29.753 1.613 1.732 10.310 1.603 0.700 4.853 1.559 1.726 43.957 1.613 140 1.743 30.060 1.636 1.747 10.378 1.626 0.708 4.875 1.576 1.743 44.602 1.636 141 1.756 30.160 1.651 1.762 10.506 1.640 0.716 4.886 1.592 1.756 45.010 1.651 142 1.770 30.260 1.666 1.777 10.633 1.655 0.723 4.897 1.608 1.770 45.419 1.666 143 1.783 30.361 1.681 1.791 10.761 1.669 0.731 4.908 1.624 1.783 45.828 1.681 144 1.797 30.461 1.696 1.806 10.888 1.684 0.738 4.918 1.640 1.797 46.237 1.696 145 1.810 30.562 1.711 1.821 11.016 1.699 0.746 4.929 1.656 1.810 46.646 1.711 146 1.822 30.592 1.720 1.830 11.101 1.709 0.751 4.954 1.663 1.822 46.945 1.720 147 1.834 30.622 1.730 1.840 11.187 1.720 0.755 4.979 1.671 1.834 47.244 1.730 148 1.846 30.653 1.740 1.850 11.273 1.730 0.760 5.004 1.679 1.846 47.544 1.740 149 1.858 30.683 1.750 1.860 11.359 1.741 0.765 5.029 1.687 1.858 47.843 1.750 150 1.869 30.713 1.760 1.869 11.445 1.752 0.770 5.054 1.694 1.869 48.143 1.760 151 1.880 30.741 1.767 1.879 11.504 1.759 0.775 5.060 1.711 1.880 48.423 1.767 152 1.890 30.768 1.775 1.890 11.564 1.767 0.780 5.065 1.727 1.890 48.704 1.775 153 1.900 30.796 1.783 1.900 11.624 1.775 0.785 5.070 1.743 1.900 48.984 1.783 154 1.910 30.823 1.791 1.910 11.683 1.783 0.791 5.075 1.760 1.910 49.265 1.791 155 1.920 30.850 1.798 1.920 11.743 1.790 0.796 5.080 1.776 1.920 49.545 1.798 156 1.949 32.415 1.828 1.945 12.434 1.821 0.819 5.150 1.813 1.949 50.517 1.828 157 1.977 33.980 1.858 1.971 13.125 1.852 0.842 5.220 1.850 1.977 51.489 1.85855 158 2.006 35.545 1.888 1.996 13.816 1.883 0.865 5.290 1.887 2.006 52.461 1.888 159 2.034 37.110 1.918 2.022 14.507 1.913 0.888 5.360 1.924 2.034 53.433 1.918 160 2.063 38.674 1.948 2.047 15.198 1.944 0.911 5.430 1.961 2.063 54.406 1.948 161 2.105 41.040 2.043 2.092 16.627 2.038 0.951 7.045 2.030 2.105 56.279 2.043 162 2.147 43.405 2.138 2.137 18.056 2.133 0.992 8.661 2.099 2.147 58.152 2.138 163 2.190 45.770 2.234 2.182 19.485 2.227 1.032 10.276 2.168 2.190 60.026 2.234 164 2.232 48.136 2.329 2.227 20.914 2.321 1.073 11.891 2.237 2.232 61.899 2.329 165 2.275 50.501 2.424 2.272 22.343 2.415 1.113 13.506 2.306 2.275 63.773 2.424 166 2.304 52.979 2.509 2.300 23.672 2.502 1.163 14.131 2.357 2.304 65.726 2.509 167 2.333 55.458 2.593 2.328 25.002 2.589 1.213 14.755 2.409 2.333 67.678 2.593 168 2.362 57.937 2.678 2.356 26.331 2.676 1.263 15.380 2.460 2.362 69.631 2.678 169 2.391 60.415 2.762 2.385 27.660 2.763 1.313 16.004 2.512 2.391 71.584 2.762 170 2.420 62.894 2.847 2.413 28.989 2.849 1.363 16.628 2.564 2.420 73.536 2.847 171 2.451 63.874 2.890 2.442 29.484 2.892 1.386 16.692 2.603 2.451 75.553 2.890 172 2.481 64.855 2.933 2.472 29.978 2.934 1.410 16.756 2.643 2.481 77.570 2.933 173 2.512 65.835 2.976 2.502 30.473 2.976 1.433 16.820 2.683 2.512 79.587 2.976 174 2.542 66.815 3.019 2.532 30.967 3.019 1.457 16.883 2.723 2.542 81.604 3.019 175 2.573 67.796 3.062 2.562 31.462 3.061 1.480 16.947 2.762 2.573 83.621 3.062 176 2.598 68.919 3.122 2.588 32.216 3.119 1.494 17.044 2.809 2.598 85.074 3.122 177 2.623 70.042 3.181 2.615 32.970 3.178 1.508 17.141 2.856 2.623 86.528 3.181 178 2.648 71.165 3.240 2.641 33.725 3.236 1.522 17.238 2.903 2.648 87.981 3.240 179 2.674 72.287 3.300 2.668 34.479 3.295 1.536 17.335 2.949 2.674 89.434 3.300 180 2.699 73.410 3.359 2.694 35.233 3.353 1.550 17.431 2.996 2.699 90.888 3.359 181 2.726 74.714 3.432 2.718 35.950 3.424 1.565 17.453 3.040 2.726 92.421 3.432 182 2.753 76.017 3.504 2.743 36.666 3.495 1.580 17.475 3.084 2.753 93.953 3.504 183 2.780 77.320 3.576 2.767 37.382 3.567 1.595 17.497 3.129 2.780 95.486 3.576 184 2.807 78.623 3.648 2.791 38.099 3.638 1.610 17.519 3.173 2.807 97.019 3.648 185 2.834 79.927 3.720 2.816 38.815 3.709 1.624 17.540 3.217 2.834 98.552 3.720 186 2.861 81.488 3.804 2.843 39.562 3.795 1.639 17.816 3.277 2.861 100.583 3.804 187 2.888 83.049 3.889 2.869 40.309 3.880 1.654 18.091 3.337 2.888 102.615 3.889 188 2.915 84.611 3.973 2.896 41.056 3.965 1.668 18.366 3.397 2.915 104.646 3.973 189 2.942 86.172 4.057 2.923 41.803 4.051 1.683 18.641 3.457 2.942 106.677 4.057 190 2.969 87.733 4.141 2.950 42.550 4.136 1.697 18.916 3.518 2.969 108.709 4.141 191 2.994 88.668 4.196 2.975 43.279 4.190 1.711 19.891 3.565 2.994 110.057 4.196 192 3.019 89.603 4.250 3.001 44.008 4.243 1.724 20.866 3.612 3.019 111.405 4.250 193 3.044 90.538 4.304 3.027 44.737 4.297 1.737 21.840 3.658 3.044 112.753 4.304 194 3.070 91.473 4.358 3.052 45.466 4.351 1.750 22.815 3.705 3.070 114.101 4.358 195 3.095 92.407 4.412 3.078 46.195 4.404 1.763 23.790 3.752 3.095 115.449 4.412 196 3.120 93.768 4.485 3.105 46.747 4.477 1.778 24.992 3.794 3.120 116.561 4.485 197 3.145 95.129 4.558 3.132 47.299 4.549 1.793 26.194 3.836 3.145 117.674 4.558 198 3.169 96.490 4.630 3.159 47.852 4.622 1.808 27.396 3.877 3.169 118.786 4.630 199 3.194 97.851 4.703 3.186 48.404 4.694 1.823 28.597 3.919 3.194 119.899 4.703 200 3.219 99.212 4.775 3.213 48.957 4.767 1.838 29.799 3.960 3.219 121.011 4.775 201 3.242 99.878 4.821 3.234 49.204 4.812 1.858 29.975 4.004 3.242 121.695 4.821 202 3.266 100.544 4.867 3.255 49.451 4.858 1.877 30.152 4.047 3.266 122.378 4.86756 203 3.289 101.210 4.914 3.277 49.698 4.904 1.897 30.328 4.090 3.289 123.062 4.914 204 3.312 101.876 4.960 3.298 49.945 4.950 1.916 30.504 4.133 3.312 123.745 4.960 205 3.335 102.542 5.006 3.320 50.192 4.996 1.936 30.680 4.176 3.335 124.429 5.006 206 3.362 103.507 5.037 3.346 50.698 5.029 1.948 30.747 4.193 3.362 125.599 5.037 207 3.388 104.472 5.069 3.373 51.205 5.063 1.961 30.813 4.209 3.388 126.769 5.069 208 3.415 105.437 5.101 3.399 51.711 5.097 1.973 30.879 4.225 3.415 127.939 5.101 209 3.441 106.402 5.132 3.426 52.218 5.130 1.986 30.946 4.241 3.441 129.109 5.132 210 3.468 107.366 5.164 3.452 52.724 5.164 1.998 31.012 4.257 3.468 130.279 5.164 211 3.488 108.519 5.234 3.472 53.327 5.233 2.006 32.744 4.311 3.488 132.009 5.234 212 3.509 109.671 5.304 3.492 53.931 5.303 2.015 34.476 4.365 3.509 133.740 5.304 213 3.530 110.823 5.374 3.513 54.534 5.372 2.023 36.207 4.419 3.530 135.470 5.374 214 3.550 111.976 5.444 3.533 55.137 5.442 2.031 37.939 4.473 3.550 137.201 5.444 215 3.571 113.128 5.514 3.553 55.740 5.511 2.039 39.671 4.527 3.571 138.931 5.514 216 3.591 113.763 5.564 3.571 56.057 5.559 2.044 39.822 4.565 3.591 140.070 5.564 217 3.612 114.398 5.613 3.589 56.373 5.606 2.048 39.973 4.602 3.612 141.208 5.613 218 3.632 115.033 5.663 3.608 56.689 5.654 2.053 40.125 4.640 3.632 142.347 5.663 219 3.652 115.668 5.713 3.626 57.005 5.701 2.058 40.276 4.677 3.652 143.485 5.713 220 3.672 116.304 5.763 3.644 57.321 5.749 2.062 40.427 4.715 3.672 144.624 5.763 221 3.693 116.644 5.775 3.669 57.474 5.761 2.076 40.526 4.724 3.693 144.903 5.775 222 3.714 116.984 5.787 3.693 57.626 5.773 2.089 40.626 4.732 3.714 145.182 5.787 223 3.736 117.324 5.799 3.717 57.779 5.785 2.103 40.725 4.741 3.736 145.462 5.799 224 3.757 117.663 5.811 3.741 57.931 5.797 2.117 40.825 4.750 3.757 145.741 5.811 225 3.778 118.003 5.823 3.766 58.084 5.809 2.130 40.924 4.759 3.778 146.020 5.823 226 3.795 118.158 5.828 3.782 58.158 5.814 2.160 40.962 4.764 3.795 146.177 5.828 227 3.811 118.312 5.833 3.798 58.232 5.820 2.190 41.000 4.770 3.811 146.334 5.833 228 3.828 118.466 5.838 3.815 58.307 5.825 2.219 41.038 4.775 3.828 146.491 5.838 229 3.845 118.621 5.842 3.831 58.381 5.830 2.249 41.076 4.781 3.845 146.648 5.842 230 3.862 118.775 5.847 3.848 58.455 5.835 2.278 41.114 4.786 3.862 146.805 5.847 231 3.873 118.885 5.852 3.858 58.534 5.840 2.285 41.142 4.790 3.873 147.057 5.852 232 3.884 118.995 5.856 3.868 58.612 5.845 2.292 41.171 4.794 3.884 147.308 5.856 233 3.896 119.105 5.860 3.879 58.690 5.850 2.299 41.199 4.797 3.896 147.560 5.860 234 3.907 119.215 5.865 3.889 58.769 5.855 2.306 41.228 4.801 3.907 147.812 5.865 235 3.918 119.325 5.869 3.900 58.847 5.860 2.313 41.256 4.805 3.918 148.064 5.869 236 3.924 119.407 5.874 3.907 58.990 5.865 2.315 41.285 4.808 3.924 148.450 5.874 237 3.930 119.488 5.878 3.913 59.132 5.869 2.318 41.313 4.812 3.930 148.837 5.878 238 3.935 119.570 5.883 3.920 59.275 5.874 2.320 41.341 4.815 3.935 149.223 5.883 239 3.941 119.651 5.887 3.927 59.418 5.878 2.322 41.369 4.818 3.941 149.609 5.887 240 3.947 119.733 5.892 3.934 59.560 5.883 2.325 41.397 4.822 3.947 149.996 5.89257 Alternative Fast-Pass IM240 Standards Corresponding to Composite Start-up Emission Standards in §85.2205(a)(2)(iv)
Light Duty Truck 1 &2

1982-1983 1984-1987 1988-1990 1991 Sec HC CO NOx HC CO NOx HC CO NOx HC CO NOx 30 1.064 14.776 0.562 0.585 10.661 0.513 0.585 10.661 0.298 0.477 5.069 0.254 31 1.091 15.338 0.610 0.609 11.033 0.551 0.609 11.033 0.319 0.494 5.129 0.270 32 1.118 15.900 0.657 0.633 11.405 0.590 0.633 11.405 0.340 0.512 5.189 0.285 33 1.145 16.462 0.705 0.657 11.777 0.629 0.657 11.777 0.361 0.529 5.249 0.300 34 1.172 17.023 0.752 0.681 12.149 0.667 0.681 12.149 0.382 0.547 5.309 0.316 35 1.199 17.585 0.800 0.705 12.521 0.706 0.705 12.521 0.403 0.564 5.369 0.331 36 1.237 17.834 0.804 0.730 12.895 0.711 0.730 12.895 0.407 0.582 5.562 0.334 37 1.275 18.084 0.808 0.754 13.269 0.716 0.754 13.269 0.410 0.601 5.755 0.336 38 1.313 18.333 0.813 0.779 13.643 0.721 0.779 13.643 0.414 0.619 5.948 0.339 39 1.351 18.582 0.817 0.803 14.018 0.727 0.803 14.018 0.418 0.637 6.142 0.341 40 1.389 18.832 0.822 0.828 14.392 0.732 0.828 14.392 0.422 0.656 6.335 0.344 41 1.459 19.867 0.869 0.854 15.098 0.796 0.854 15.098 0.451 0.681 6.890 0.368 42 1.529 20.902 0.915 0.880 15.805 0.861 0.880 15.805 0.479 0.707 7.445 0.392 43 1.599 21.937 0.962 0.907 16.511 0.925 0.907 16.511 0.508 0.732 7.999 0.416 44 1.669 22.972 1.009 0.933 17.217 0.989 0.933 17.217 0.536 0.758 8.554 0.440 45 1.738 24.008 1.056 0.959 17.924 1.053 0.959 17.924 0.565 0.783 9.109 0.464 46 1.784 24.572 1.098 0.989 18.458 1.096 0.989 18.458 0.587 0.799 9.593 0.480 47 1.830 25.136 1.140 1.019 18.992 1.138 1.019 18.992 0.609 0.816 10.076 0.496 48 1.876 25.701 1.182 1.050 19.526 1.180 1.050 19.526 0.631 0.832 10.560 0.512 49 1.922 26.265 1.224 1.080 20.060 1.223 1.080 20.060 0.652 0.848 11.044 0.528 50 1.968 26.830 1.266 1.110 20.594 1.265 1.110 20.594 0.674 0.864 11.527 0.543 51 2.020 27.642 1.305 1.146 21.719 1.294 1.146 21.719 0.701 0.891 12.038 0.563 52 2.072 28.454 1.343 1.182 22.845 1.324 1.182 22.845 0.728 0.917 12.549 0.582 53 2.124 29.266 1.381 1.218 23.970 1.353 1.218 23.970 0.755 0.943 13.059 0.601 54 2.176 30.079 1.420 1.254 25.095 1.382 1.254 25.095 0.782 0.969 13.570 0.621 55 2.228 30.891 1.458 1.290 26.221 1.411 1.290 26.221 0.809 0.995 14.081 0.640 56 2.265 31.485 1.490 1.310 26.449 1.449 1.310 26.449 0.826 1.015 14.438 0.653 57 2.302 32.078 1.522 1.330 26.677 1.486 1.330 26.677 0.842 1.035 14.796 0.666 58 2.340 32.672 1.555 1.350 26.905 1.523 1.350 26.905 0.859 1.055 15.154 0.679 59 2.377 33.266 1.587 1.370 27.133 1.560 1.370 27.133 0.876 1.075 15.512 0.692 60 2.415 33.860 1.619 1.390 27.361 1.597 1.390 27.361 0.892 1.095 15.870 0.705 61 2.451 34.449 1.637 1.405 27.372 1.611 1.405 27.372 0.903 1.109 16.268 0.714 62 2.487 35.037 1.656 1.420 27.383 1.625 1.420 27.383 0.915 1.124 16.667 0.723 63 2.523 35.626 1.674 1.434 27.393 1.639 1.434 27.393 0.926 1.138 17.066 0.732 64 2.559 36.215 1.693 1.449 27.404 1.653 1.449 27.404 0.938 1.153 17.465 0.741 65 2.595 36.804 1.711 1.464 27.415 1.667 1.464 27.415 0.949 1.167 17.863 0.750 66 2.639 37.463 1.737 1.497 28.054 1.699 1.497 28.054 0.960 1.182 18.249 0.759 67 2.683 38.122 1.763 1.530 28.694 1.732 1.530 28.694 0.972 1.196 18.635 0.768 68 2.728 38.782 1.789 1.563 29.333 1.765 1.563 29.333 0.983 1.211 19.020 0.77758 69 2.772 39.441 1.815 1.596 29.972 1.797 1.596 29.972 0.994 1.225 19.406 0.786 70 2.817 40.100 1.841 1.629 30.612 1.830 1.629 30.612 1.005 1.239 19.792 0.795 71 2.859 40.631 1.862 1.650 31.097 1.854 1.650 31.097 1.016 1.255 19.906 0.805 72 2.901 41.161 1.884 1.672 31.583 1.878 1.672 31.583 1.028 1.271 20.020 0.815 73 2.943 41.692 1.906 1.694 32.068 1.902 1.694 32.068 1.039 1.287 20.134 0.825 74 2.985 42.222 1.928 1.715 32.554 1.925 1.715 32.554 1.051 1.303 20.248 0.835 75 3.027 42.753 1.950 1.737 33.039 1.949 1.737 33.039 1.062 1.318 20.362 0.845 76 3.061 43.694 1.978 1.760 33.193 1.977 1.760 33.193 1.074 1.331 20.782 0.859 77 3.096 44.636 2.007 1.782 33.347 2.005 1.782 33.347 1.085 1.344 21.202 0.874 78 3.130 45.577 2.035 1.805 33.501 2.033 1.805 33.501 1.096 1.357 21.623 0.888 79 3.165 46.519 2.063 1.828 33.655 2.061 1.828 33.655 1.108 1.370 22.043 0.902 80 3.200 47.461 2.092 1.851 33.809 2.089 1.851 33.809 1.119 1.382 22.463 0.916 81 3.237 47.831 2.111 1.872 34.035 2.111 1.872 34.035 1.131 1.407 22.571 0.925 82 3.275 48.201 2.130 1.894 34.261 2.132 1.894 34.261 1.144 1.431 22.678 0.934 83 3.313 48.571 2.149 1.915 34.488 2.154 1.915 34.488 1.156 1.455 22.786 0.942 84 3.351 48.941 2.168 1.937 34.714 2.175 1.937 34.714 1.169 1.480 22.894 0.951 85 3.389 49.311 2.187 1.958 34.941 2.197 1.958 34.941 1.181 1.504 23.001 0.960 86 3.432 49.503 2.189 1.973 35.115 2.200 1.973 35.115 1.182 1.531 23.112 0.961 87 3.475 49.694 2.192 1.988 35.289 2.203 1.988 35.289 1.182 1.558 23.223 0.963 88 3.518 49.886 2.194 2.002 35.463 2.206 2.002 35.463 1.183 1.586 23.334 0.964 89 3.562 50.077 2.197 2.017 35.637 2.209 2.017 35.637 1.184 1.613 23.445 0.966 90 3.605 50.269 2.199 2.032 35.811 2.212 2.032 35.811 1.185 1.640 23.556 0.967 91 3.645 50.447 2.200 2.044 35.968 2.213 2.044 35.968 1.186 1.654 23.558 0.968 92 3.686 50.626 2.201 2.056 36.125 2.214 2.056 36.125 1.187 1.668 23.560 0.968 93 3.727 50.805 2.202 2.068 36.282 2.215 2.068 36.282 1.188 1.682 23.562 0.968 94 3.767 50.984 2.203 2.081 36.440 2.216 2.081 36.440 1.189 1.696 23.564 0.969 95 3.808 51.162 2.204 2.093 36.597 2.217 2.093 36.597 1.190 1.710 23.567 0.969 96 3.853 51.779 2.212 2.111 36.968 2.227 2.111 36.968 1.195 1.727 23.924 0.978 97 3.898 52.395 2.219 2.129 37.339 2.236 2.129 37.339 1.201 1.744 24.282 0.987 98 3.943 53.012 2.227 2.147 37.710 2.245 2.147 37.710 1.207 1.762 24.639 0.996 99 3.988 53.628 2.234 2.165 38.081 2.254 2.165 38.081 1.213 1.779 24.997 1.004 100 4.033 54.245 2.242 2.183 38.453 2.263 2.183 38.453 1.218 1.796 25.355 1.013 101 4.081 55.131 2.322 2.221 40.429 2.342 2.221 40.429 1.259 1.819 25.871 1.045 102 4.128 56.016 2.403 2.258 42.405 2.420 2.258 42.405 1.299 1.842 26.387 1.076 103 4.175 56.902 2.484 2.295 44.382 2.498 2.295 44.382 1.340 1.865 26.903 1.107 104 4.223 57.788 2.565 2.333 46.358 2.576 2.333 46.358 1.380 1.887 27.419 1.139 105 4.270 58.674 2.646 2.370 48.335 2.654 2.370 48.335 1.421 1.910 27.935 1.170 106 4.300 59.222 2.721 2.404 49.060 2.740 2.404 49.060 1.458 1.936 28.221 1.201 107 4.331 59.771 2.797 2.437 49.785 2.826 2.437 49.785 1.495 1.962 28.506 1.232 108 4.361 60.319 2.872 2.471 50.511 2.912 2.471 50.511 1.531 1.988 28.792 1.263 109 4.391 60.868 2.948 2.504 51.236 2.998 2.504 51.236 1.568 2.014 29.077 1.294 110 4.421 61.416 3.023 2.538 51.962 3.084 2.538 51.962 1.605 2.040 29.363 1.325 111 4.449 61.935 3.038 2.560 52.113 3.101 2.560 52.113 1.615 2.057 29.405 1.332 112 4.476 62.455 3.053 2.582 52.265 3.118 2.582 52.265 1.624 2.074 29.447 1.338 113 4.503 62.974 3.067 2.604 52.417 3.136 2.604 52.417 1.634 2.090 29.489 1.34459 114 4.531 63.493 3.082 2.625 52.569 3.153 2.625 52.569 1.644 2.107 29.531 1.350 115 4.558 64.013 3.097 2.647 52.721 3.170 2.647 52.721 1.653 2.124 29.573 1.357 116 4.600 64.559 3.099 2.673 52.723 3.173 2.673 52.723 1.656 2.152 29.865 1.359 117 4.642 65.105 3.102 2.698 52.724 3.175 2.698 52.724 1.658 2.179 30.157 1.361 118 4.684 65.651 3.105 2.723 52.726 3.178 2.723 52.726 1.661 2.207 30.449 1.363 119 4.726 66.197 3.108 2.749 52.728 3.181 2.749 52.728 1.663 2.234 30.741 1.365 120 4.768 66.743 3.111 2.774 52.729 3.184 2.774 52.729 1.666 2.262 31.033 1.368 121 4.804 67.600 3.134 2.799 53.168 3.206 2.799 53.168 1.684 2.276 31.230 1.383 122 4.840 68.458 3.156 2.824 53.606 3.229 2.824 53.606 1.703 2.290 31.428 1.399 123 4.876 69.315 3.179 2.850 54.044 3.251 2.850 54.044 1.722 2.304 31.625 1.415 124 4.911 70.173 3.202 2.875 54.483 3.274 2.875 54.483 1.741 2.318 31.823 1.431 125 4.947 71.030 3.224 2.900 54.921 3.296 2.900 54.921 1.759 2.332 32.020 1.446 126 4.983 71.729 3.241 2.920 55.078 3.310 2.920 55.078 1.770 2.355 32.099 1.453 127 5.019 72.427 3.257 2.941 55.236 3.323 2.941 55.236 1.780 2.377 32.178 1.460 128 5.055 73.126 3.274 2.961 55.393 3.337 2.961 55.393 1.790 2.399 32.256 1.468 129 5.091 73.825 3.290 2.981 55.551 3.350 2.981 55.551 1.800 2.422 32.335 1.475 130 5.126 74.523 3.307 3.001 55.708 3.364 3.001 55.708 1.811 2.444 32.413 1.482 131 5.178 75.331 3.311 3.027 55.921 3.370 3.027 55.921 1.813 2.464 32.638 1.484 132 5.230 76.139 3.316 3.052 56.134 3.376 3.052 56.134 1.816 2.485 32.862 1.487 133 5.282 76.947 3.321 3.078 56.346 3.382 3.078 56.346 1.819 2.505 33.086 1.490 134 5.334 77.755 3.326 3.103 56.559 3.388 3.103 56.559 1.822 2.525 33.310 1.492 135 5.386 78.563 3.331 3.129 56.771 3.394 3.129 56.771 1.825 2.545 33.534 1.495 136 5.468 79.372 3.365 3.167 57.854 3.432 3.167 57.854 1.851 2.573 34.147 1.520 137 5.549 80.181 3.398 3.206 58.937 3.469 3.206 58.937 1.877 2.600 34.760 1.546 138 5.630 80.990 3.431 3.244 60.020 3.507 3.244 60.020 1.903 2.628 35.373 1.571 139 5.712 81.798 3.464 3.283 61.102 3.544 3.283 61.102 1.929 2.655 35.985 1.596 140 5.793 82.607 3.498 3.322 62.185 3.582 3.322 62.185 1.955 2.682 36.598 1.622 141 5.825 83.486 3.536 3.342 62.366 3.639 3.342 62.366 1.977 2.702 36.880 1.639 142 5.856 84.365 3.575 3.363 62.548 3.697 3.363 62.548 1.999 2.722 37.162 1.656 143 5.888 85.245 3.613 3.383 62.729 3.754 3.383 62.729 2.021 2.742 37.444 1.673 144 5.920 86.124 3.652 3.404 62.910 3.811 3.404 62.910 2.043 2.762 37.727 1.691 145 5.951 87.003 3.690 3.425 63.091 3.869 3.425 63.091 2.065 2.782 38.009 1.708 146 5.975 87.915 3.718 3.453 63.539 3.892 3.453 63.539 2.074 2.797 38.632 1.717 147 5.998 88.827 3.745 3.482 63.987 3.916 3.482 63.987 2.082 2.811 39.255 1.726 148 6.022 89.739 3.772 3.510 64.435 3.939 3.510 64.435 2.090 2.825 39.878 1.735 149 6.046 90.652 3.800 3.539 64.883 3.963 3.539 64.883 2.098 2.839 40.501 1.743 150 6.069 91.564 3.827 3.568 65.331 3.986 3.568 65.331 2.106 2.853 41.124 1.752 151 6.099 92.475 3.852 3.595 65.704 4.000 3.595 65.704 2.117 2.868 41.450 1.765 152 6.129 93.387 3.877 3.623 66.077 4.014 3.623 66.077 2.129 2.883 41.776 1.778 153 6.159 94.298 3.901 3.650 66.450 4.029 3.650 66.450 2.141 2.898 42.102 1.791 154 6.189 95.209 3.926 3.677 66.823 4.043 3.677 66.823 2.152 2.913 42.428 1.803 155 6.219 96.121 3.951 3.705 67.197 4.057 3.705 67.197 2.164 2.927 42.754 1.816 156 6.313 97.599 4.030 3.767 69.206 4.117 3.767 69.206 2.205 2.969 44.233 1.849 157 6.407 99.077 4.110 3.829 71.215 4.176 3.829 71.215 2.247 3.011 45.712 1.882 158 6.501 100.555 4.190 3.891 73.225 4.236 3.891 73.225 2.289 3.053 47.191 1.91560 159 6.595 102.033 4.269 3.953 75.234 4.295 3.953 75.234 2.330 3.095 48.670 1.948 160 6.689 103.511 4.349 4.015 77.243 4.355 4.015 77.243 2.372 3.136 50.149 1.981 161 7.010 107.552 4.542 4.078 79.985 4.551 4.078 79.985 2.472 3.182 51.569 2.071 162 7.331 111.593 4.736 4.142 82.727 4.747 4.142 82.727 2.571 3.227 52.988 2.162 163 7.652 115.634 4.930 4.205 85.469 4.943 4.205 85.469 2.671 3.272 54.408 2.252 164 7.972 119.676 5.123 4.268 88.211 5.139 4.268 88.211 2.770 3.318 55.828 2.343 165 8.293 123.717 5.317 4.332 90.953 5.335 4.332 90.953 2.870 3.363 57.247 2.434 166 8.576 125.252 5.496 4.380 93.266 5.516 4.380 93.266 2.961 3.410 58.958 2.509 167 8.859 126.786 5.676 4.428 95.579 5.696 4.428 95.579 3.053 3.458 60.670 2.584 168 9.142 128.321 5.855 4.477 97.892 5.876 4.477 97.892 3.144 3.505 62.381 2.659 169 9.425 129.855 6.034 4.525 100.205 6.056 4.525 100.205 3.235 3.552 64.092 2.735 170 9.708 131.390 6.213 4.573 102.517 6.237 4.573 102.517 3.327 3.600 65.804 2.810 171 9.788 132.095 6.318 4.618 103.813 6.345 4.618 103.813 3.373 3.644 66.939 2.863 172 9.868 132.801 6.422 4.664 105.109 6.452 4.664 105.109 3.420 3.688 68.075 2.916 173 9.948 133.506 6.527 4.709 106.404 6.560 4.709 106.404 3.467 3.732 69.210 2.969 174 10.028 134.211 6.632 4.754 107.700 6.668 4.754 107.700 3.513 3.776 70.345 3.022 175 10.107 134.917 6.736 4.799 108.995 6.776 4.799 108.995 3.560 3.821 71.481 3.075 176 10.174 137.703 6.876 4.858 110.733 6.910 4.858 110.733 3.626 3.856 73.077 3.130 177 10.242 140.490 7.016 4.917 112.471 7.045 4.917 112.471 3.692 3.891 74.674 3.185 178 10.309 143.276 7.155 4.977 114.209 7.179 4.977 114.209 3.758 3.927 76.271 3.240 179 10.376 146.063 7.295 5.036 115.946 7.313 5.036 115.946 3.824 3.962 77.867 3.295 180 10.443 148.849 7.435 5.095 117.684 7.447 5.095 117.684 3.889 3.997 79.464 3.350 181 10.506 152.900 7.603 5.158 119.775 7.621 5.158 119.775 3.979 4.024 81.282 3.430 182 10.570 156.950 7.772 5.221 121.866 7.795 5.221 121.866 4.069 4.050 83.100 3.509 183 10.634 161.001 7.941 5.284 123.956 7.969 5.284 123.956 4.159 4.077 84.919 3.589 184 10.698 165.051 8.110 5.347 126.047 8.143 5.347 126.047 4.248 4.104 86.737 3.668 185 10.761 169.102 8.279 5.411 128.138 8.318 5.411 128.138 4.338 4.131 88.555 3.748 186 10.836 171.850 8.477 5.428 129.673 8.499 5.428 129.673 4.443 4.154 90.333 3.841 187 10.911 174.598 8.675 5.446 131.209 8.681 5.446 131.209 4.547 4.178 92.110 3.934 188 10.986 177.345 8.873 5.463 132.745 8.862 5.463 132.745 4.652 4.202 93.888 4.026 189 11.061 180.093 9.071 5.481 134.281 9.043 5.481 134.281 4.756 4.225 95.665 4.119 190 11.136 182.841 9.269 5.499 135.816 9.225 5.499 135.816 4.861 4.249 97.442 4.212 191 11.307 184.591 9.422 5.561 137.198 9.386 5.561 137.198 4.932 4.285 98.856 4.274 192 11.477 186.341 9.576 5.623 138.580 9.547 5.623 138.580 5.003 4.321 100.271 4.336 193 11.648 188.091 9.730 5.686 139.961 9.708 5.686 139.961 5.074 4.357 101.685 4.398 194 11.819 189.841 9.884 5.748 141.343 9.869 5.748 141.343 5.146 4.393 103.099 4.459 195 11.990 191.591 10.038 5.810 142.724 10.030 5.810 142.724 5.217 4.430 104.513 4.521 196 12.067 194.037 10.193 5.828 144.052 10.188 5.828 144.052 5.301 4.460 106.134 4.589 197 12.144 196.482 10.348 5.845 145.381 10.346 5.845 145.381 5.385 4.490 107.755 4.658 198 12.221 198.927 10.503 5.863 146.709 10.504 5.863 146.709 5.469 4.520 109.376 4.726 199 12.298 201.373 10.658 5.880 148.037 10.662 5.880 148.037 5.553 4.550 110.997 4.795 200 12.376 203.818 10.813 5.898 149.365 10.820 5.898 149.365 5.637 4.580 112.617 4.863 201 12.463 204.868 10.912 5.942 150.214 10.948 5.942 150.214 5.692 4.623 113.207 4.906 202 12.551 205.918 11.012 5.986 151.063 11.075 5.986 151.063 5.746 4.666 113.796 4.949 203 12.639 206.967 11.111 6.029 151.912 11.203 6.029 151.912 5.801 4.709 114.385 4.99361 204 12.726 208.017 11.211 6.073 152.760 11.330 6.073 152.760 5.856 4.752 114.974 5.036 205 12.814 209.067 11.310 6.117 153.609 11.458 6.117 153.609 5.911 4.795 115.563 5.079 206 12.891 211.915 11.381 6.174 154.888 11.530 6.174 154.888 5.951 4.848 116.847 5.119 207 12.969 214.764 11.452 6.231 156.166 11.601 6.231 156.166 5.990 4.901 118.131 5.160 208 13.046 217.612 11.523 6.288 157.445 11.673 6.288 157.445 6.030 4.955 119.415 5.201 209 13.124 220.460 11.594 6.345 158.724 11.745 6.345 158.724 6.070 5.008 120.699 5.241 210 13.201 223.309 11.665 6.401 160.002 11.817 6.401 160.002 6.110 5.061 121.983 5.282 211 13.243 226.365 11.862 6.451 161.606 11.984 6.451 161.606 6.194 5.090 123.498 5.355 212 13.285 229.421 12.060 6.500 163.210 12.152 6.500 163.210 6.278 5.119 125.012 5.429 213 13.327 232.478 12.257 6.550 164.814 12.319 6.550 164.814 6.362 5.147 126.526 5.502 214 13.370 235.534 12.455 6.599 166.418 12.486 6.599 166.418 6.446 5.176 128.040 5.576 215 13.412 238.591 12.653 6.649 168.022 12.653 6.649 168.022 6.530 5.204 129.554 5.649 216 13.470 240.891 12.778 6.693 168.948 12.780 6.693 168.948 6.585 5.240 130.345 5.695 217 13.528 243.191 12.904 6.737 169.874 12.906 6.737 169.874 6.640 5.275 131.136 5.741 218 13.586 245.492 13.030 6.782 170.800 13.032 6.782 170.800 6.695 5.310 131.928 5.787 219 13.645 247.792 13.156 6.826 171.726 13.159 6.826 171.726 6.750 5.345 132.719 5.833 220 13.703 250.092 13.282 6.870 172.653 13.285 6.870 172.653 6.804 5.380 133.510 5.879 221 13.896 250.710 13.307 6.946 173.200 13.314 6.946 173.200 6.818 5.436 133.899 5.888 222 14.088 251.329 13.332 7.022 173.748 13.343 7.022 173.748 6.831 5.492 134.287 5.896 223 14.281 251.947 13.358 7.098 174.295 13.371 7.098 174.295 6.844 5.548 134.676 5.905 224 14.474 252.565 13.383 7.173 174.843 13.400 7.173 174.843 6.857 5.604 135.064 5.913 225 14.667 253.184 13.409 7.249 175.391 13.429 7.249 175.391 6.870 5.660 135.453 5.922 226 14.845 253.888 13.422 7.334 175.611 13.440 7.334 175.611 6.877 5.699 135.633 5.927 227 15.023 254.593 13.436 7.419 175.831 13.452 7.419 175.831 6.884 5.738 135.814 5.931 228 15.201 255.297 13.450 7.504 176.051 13.464 7.504 176.051 6.891 5.776 135.995 5.936 229 15.379 256.002 13.464 7.589 176.271 13.475 7.589 176.271 6.897 5.815 136.176 5.941 230 15.557 256.706 13.478 7.674 176.491 13.487 7.674 176.491 6.904 5.854 136.356 5.946 231 15.658 257.286 13.488 7.710 176.612 13.498 7.710 176.612 6.910 5.875 136.581 5.951 232 15.759 257.866 13.499 7.746 176.732 13.508 7.746 176.732 6.916 5.897 136.806 5.956 233 15.861 258.445 13.510 7.782 176.853 13.519 7.782 176.853 6.922 5.918 137.031 5.962 234 15.962 259.025 13.521 7.818 176.974 13.530 7.818 176.974 6.928 5.940 137.256 5.967 235 16.063 259.605 13.531 7.853 177.095 13.540 7.853 177.095 6.934 5.961 137.482 5.972 236 16.104 259.940 13.543 7.867 177.463 13.551 7.867 177.463 6.940 5.977 137.680 5.978 237 16.144 260.276 13.554 7.881 177.830 13.561 7.881 177.830 6.946 5.994 137.879 5.983 238 16.185 260.612 13.566 7.894 178.198 13.572 7.894 178.198 6.951 6.010 138.078 5.989 239 16.225 260.947 13.577 7.908 178.566 13.582 7.908 178.566 6.957 6.026 138.277 5.994 240 16.265 261.283 13.589 7.922 178.933 13.592 7.922 178.933 6.962 6.042 138.476 6.00062 Alternative Fast-Pass IM240 Standards Corresponding to Composite Start-up Emission Standards in §85.2205(a)(2)(vi)
Light Duty Truck 3&4

1982-1983 1984-1987 1988-1990 1991 Sec HC CO NOx HC CO NOx HC CO NOx HC CO NOx 30 1.064 14.776 0.513 0.585 10.661 0.513 0.585 10.661 0.436 0.477 5.069 0.395 31 1.091 15.338 0.551 0.609 11.033 0.551 0.609 11.033 0.463 0.494 5.129 0.420 32 1.118 15.900 0.590 0.633 11.405 0.590 0.633 11.405 0.490 0.512 5.189 0.445 33 1.145 16.462 0.629 0.657 11.777 0.629 0.657 11.777 0.517 0.529 5.249 0.470 34 1.172 17.023 0.667 0.681 12.149 0.667 0.681 12.149 0.544 0.547 5.309 0.495 35 1.199 17.585 0.706 0.705 12.521 0.706 0.705 12.521 0.572 0.564 5.369 0.520 36 1.237 17.834 0.711 0.730 12.895 0.711 0.730 12.895 0.576 0.582 5.562 0.524 37 1.275 18.084 0.716 0.754 13.269 0.716 0.754 13.269 0.580 0.601 5.755 0.527 38 1.313 18.333 0.721 0.779 13.643 0.721 0.779 13.643 0.584 0.619 5.948 0.531 39 1.351 18.582 0.727 0.803 14.018 0.727 0.803 14.018 0.588 0.637 6.142 0.535 40 1.389 18.832 0.732 0.828 14.392 0.732 0.828 14.392 0.592 0.656 6.335 0.539 41 1.459 19.867 0.796 0.854 15.098 0.796 0.854 15.098 0.636 0.681 6.890 0.578 42 1.529 20.902 0.861 0.880 15.805 0.861 0.880 15.805 0.681 0.707 7.445 0.617 43 1.599 21.937 0.925 0.907 16.511 0.925 0.907 16.511 0.726 0.732 7.999 0.657 44 1.669 22.972 0.989 0.933 17.217 0.989 0.933 17.217 0.771 0.758 8.554 0.696 45 1.738 24.008 1.053 0.959 17.924 1.053 0.959 17.924 0.815 0.783 9.109 0.735 46 1.784 24.572 1.096 0.989 18.458 1.096 0.989 18.458 0.840 0.799 9.593 0.760 47 1.830 25.136 1.138 1.019 18.992 1.138 1.019 18.992 0.866 0.816 10.076 0.785 48 1.876 25.701 1.180 1.050 19.526 1.180 1.050 19.526 0.891 0.832 10.560 0.810 49 1.922 26.265 1.223 1.080 20.060 1.223 1.080 20.060 0.916 0.848 11.044 0.835 50 1.968 26.830 1.265 1.110 20.594 1.265 1.110 20.594 0.941 0.864 11.527 0.860 51 2.020 27.642 1.294 1.146 21.719 1.294 1.146 21.719 0.978 0.891 12.038 0.893 52 2.072 28.454 1.324 1.182 22.845 1.324 1.182 22.845 1.016 0.917 12.549 0.926 53 2.124 29.266 1.353 1.218 23.970 1.353 1.218 23.970 1.053 0.943 13.059 0.959 54 2.176 30.079 1.382 1.254 25.095 1.382 1.254 25.095 1.090 0.969 13.570 0.992 55 2.228 30.891 1.411 1.290 26.221 1.411 1.290 26.221 1.128 0.995 14.081 1.026 56 2.265 31.485 1.449 1.310 26.449 1.449 1.310 26.449 1.160 1.015 14.438 1.051 57 2.302 32.078 1.486 1.330 26.677 1.486 1.330 26.677 1.192 1.035 14.796 1.077 58 2.340 32.672 1.523 1.350 26.905 1.523 1.350 26.905 1.224 1.055 15.154 1.103 59 2.377 33.266 1.560 1.370 27.133 1.560 1.370 27.133 1.256 1.075 15.512 1.129 60 2.415 33.860 1.597 1.390 27.361 1.597 1.390 27.361 1.288 1.095 15.870 1.155 61 2.451 34.487 1.611 1.405 27.372 1.611 1.405 27.372 1.301 1.109 16.268 1.166 62 2.487 35.113 1.625 1.420 27.383 1.625 1.420 27.383 1.313 1.124 16.667 1.177 63 2.523 35.740 1.639 1.434 27.393 1.639 1.434 27.393 1.326 1.138 17.066 1.188 64 2.559 36.367 1.653 1.449 27.404 1.653 1.449 27.404 1.338 1.153 17.465 1.200 65 2.595 36.994 1.667 1.464 27.415 1.667 1.464 27.415 1.351 1.167 17.863 1.211 66 2.639 37.728 1.699 1.497 28.054 1.699 1.497 28.054 1.366 1.182 18.249 1.230 67 2.683 38.462 1.732 1.530 28.694 1.732 1.530 28.694 1.382 1.196 18.635 1.250 68 2.728 39.197 1.765 1.563 29.333 1.765 1.563 29.333 1.397 1.211 19.020 1.26963 69 2.772 39.931 1.797 1.596 29.972 1.797 1.596 29.972 1.412 1.225 19.406 1.289 70 2.817 40.666 1.830 1.629 30.612 1.830 1.629 30.612 1.427 1.239 19.792 1.308 71 2.859 41.083 1.854 1.650 31.097 1.854 1.650 31.097 1.443 1.255 19.906 1.321 72 2.901 41.500 1.878 1.672 31.583 1.878 1.672 31.583 1.459 1.271 20.020 1.334 73 2.943 41.918 1.902 1.694 32.068 1.902 1.694 32.068 1.475 1.287 20.134 1.347 74 2.985 42.335 1.925 1.715 32.554 1.925 1.715 32.554 1.491 1.303 20.248 1.361 75 3.027 42.753 1.949 1.737 33.039 1.949 1.737 33.039 1.507 1.318 20.362 1.374 76 3.061 43.705 1.977 1.760 33.193 1.977 1.760 33.193 1.528 1.331 20.782 1.391 77 3.096 44.657 2.005 1.782 33.347 2.005 1.782 33.347 1.550 1.344 21.202 1.409 78 3.130 45.609 2.033 1.805 33.501 2.033 1.805 33.501 1.571 1.357 21.623 1.426 79 3.165 46.562 2.061 1.828 33.655 2.061 1.828 33.655 1.593 1.370 22.043 1.444 80 3.200 47.514 2.089 1.851 33.809 2.089 1.851 33.809 1.615 1.382 22.463 1.461 81 3.237 47.873 2.111 1.872 34.035 2.111 1.872 34.035 1.623 1.407 22.571 1.475 82 3.275 48.233 2.132 1.894 34.261 2.132 1.894 34.261 1.632 1.431 22.678 1.489 83 3.313 48.592 2.154 1.915 34.488 2.154 1.915 34.488 1.640 1.455 22.786 1.503 84 3.351 48.952 2.175 1.937 34.714 2.175 1.937 34.714 1.648 1.480 22.894 1.517 85 3.389 49.311 2.197 1.958 34.941 2.197 1.958 34.941 1.657 1.504 23.001 1.531 86 3.432 49.503 2.200 1.973 35.115 2.200 1.973 35.115 1.659 1.531 23.112 1.531 87 3.475 49.694 2.203 1.988 35.289 2.203 1.988 35.289 1.661 1.558 23.223 1.532 88 3.518 49.886 2.206 2.002 35.463 2.206 2.002 35.463 1.663 1.586 23.334 1.533 89 3.562 50.077 2.209 2.017 35.637 2.209 2.017 35.637 1.665 1.613 23.445 1.533 90 3.605 50.269 2.212 2.032 35.811 2.212 2.032 35.811 1.667 1.640 23.556 1.534 91 3.645 50.447 2.213 2.044 35.968 2.213 2.044 35.968 1.668 1.654 23.558 1.534 92 3.686 50.626 2.214 2.056 36.125 2.214 2.056 36.125 1.669 1.668 23.560 1.534 93 3.727 50.805 2.215 2.068 36.282 2.215 2.068 36.282 1.671 1.682 23.562 1.535 94 3.767 50.984 2.216 2.081 36.440 2.216 2.081 36.440 1.672 1.696 23.564 1.535 95 3.808 51.162 2.217 2.093 36.597 2.217 2.093 36.597 1.674 1.710 23.567 1.535 96 3.853 51.779 2.227 2.111 36.968 2.227 2.111 36.968 1.680 1.727 23.924 1.547 97 3.898 52.395 2.236 2.129 37.339 2.236 2.129 37.339 1.686 1.744 24.282 1.558 98 3.943 53.012 2.245 2.147 37.710 2.245 2.147 37.710 1.692 1.762 24.639 1.570 99 3.988 53.628 2.254 2.165 38.081 2.254 2.165 38.081 1.698 1.779 24.997 1.581 100 4.033 54.245 2.263 2.183 38.453 2.263 2.183 38.453 1.704 1.796 25.355 1.593 101 4.081 55.131 2.342 2.221 40.429 2.342 2.221 40.429 1.779 1.819 25.871 1.636 102 4.128 56.016 2.420 2.258 42.405 2.420 2.258 42.405 1.854 1.842 26.387 1.678 103 4.175 56.902 2.498 2.295 44.382 2.498 2.295 44.382 1.928 1.865 26.903 1.721 104 4.223 57.788 2.576 2.333 46.358 2.576 2.333 46.358 2.003 1.887 27.419 1.764 105 4.270 58.674 2.654 2.370 48.335 2.654 2.370 48.335 2.078 1.910 27.935 1.807 106 4.300 59.222 2.740 2.404 49.060 2.740 2.404 49.060 2.132 1.936 28.221 1.864 107 4.331 59.771 2.826 2.437 49.785 2.826 2.437 49.785 2.187 1.962 28.506 1.921 108 4.361 60.319 2.912 2.471 50.511 2.912 2.471 50.511 2.241 1.988 28.792 1.978 109 4.391 60.868 2.998 2.504 51.236 2.998 2.504 51.236 2.296 2.014 29.077 2.035 110 4.421 61.416 3.084 2.538 51.962 3.084 2.538 51.962 2.350 2.040 29.363 2.092 111 4.449 61.935 3.101 2.560 52.113 3.101 2.560 52.113 2.365 2.057 29.405 2.107 112 4.476 62.455 3.118 2.582 52.265 3.118 2.582 52.265 2.381 2.074 29.447 2.121 113 4.503 62.974 3.136 2.604 52.417 3.136 2.604 52.417 2.396 2.090 29.489 2.13564 114 4.531 63.493 3.153 2.625 52.569 3.153 2.625 52.569 2.411 2.107 29.531 2.149 115 4.558 64.013 3.170 2.647 52.721 3.170 2.647 52.721 2.426 2.124 29.573 2.163 116 4.600 64.559 3.173 2.673 52.723 3.173 2.673 52.723 2.430 2.152 29.865 2.166 117 4.642 65.105 3.175 2.698 52.724 3.175 2.698 52.724 2.433 2.179 30.157 2.169 118 4.684 65.651 3.178 2.723 52.726 3.178 2.723 52.726 2.437 2.207 30.449 2.173 119 4.726 66.197 3.181 2.749 52.728 3.181 2.749 52.728 2.441 2.234 30.741 2.176 120 4.768 66.743 3.184 2.774 52.729 3.184 2.774 52.729 2.445 2.262 31.033 2.179 121 4.804 67.600 3.206 2.799 53.168 3.206 2.799 53.168 2.467 2.276 31.230 2.200 122 4.840 68.458 3.229 2.824 53.606 3.229 2.824 53.606 2.489 2.290 31.428 2.222 123 4.876 69.315 3.251 2.850 54.044 3.251 2.850 54.044 2.512 2.304 31.625 2.243 124 4.911 70.173 3.274 2.875 54.483 3.274 2.875 54.483 2.534 2.318 31.823 2.265 125 4.947 71.030 3.296 2.900 54.921 3.296 2.900 54.921 2.557 2.332 32.020 2.286 126 4.983 71.729 3.310 2.920 55.078 3.310 2.920 55.078 2.569 2.355 32.099 2.297 127 5.019 72.427 3.323 2.941 55.236 3.323 2.941 55.236 2.580 2.377 32.178 2.307 128 5.055 73.126 3.337 2.961 55.393 3.337 2.961 55.393 2.592 2.399 32.256 2.318 129 5.091 73.825 3.350 2.981 55.551 3.350 2.981 55.551 2.604 2.422 32.335 2.329 130 5.126 74.523 3.364 3.001 55.708 3.364 3.001 55.708 2.616 2.444 32.413 2.339 131 5.178 75.331 3.370 3.027 55.921 3.370 3.027 55.921 2.619 2.464 32.638 2.343 132 5.230 76.139 3.376 3.052 56.134 3.376 3.052 56.134 2.623 2.485 32.862 2.347 133 5.282 76.947 3.382 3.078 56.346 3.382 3.078 56.346 2.627 2.505 33.086 2.350 134 5.334 77.755 3.388 3.103 56.559 3.388 3.103 56.559 2.630 2.525 33.310 2.354 135 5.386 78.563 3.394 3.129 56.771 3.394 3.129 56.771 2.634 2.545 33.534 2.358 136 5.468 79.372 3.432 3.167 57.854 3.432 3.167 57.854 2.672 2.573 34.147 2.395 137 5.549 80.181 3.469 3.206 58.937 3.469 3.206 58.937 2.711 2.600 34.760 2.431 138 5.630 80.990 3.507 3.244 60.020 3.507 3.244 60.020 2.749 2.628 35.373 2.468 139 5.712 81.798 3.544 3.283 61.102 3.544 3.283 61.102 2.787 2.655 35.985 2.505 140 5.793 82.607 3.582 3.322 62.185 3.582 3.322 62.185 2.826 2.682 36.598 2.542 141 5.825 83.486 3.639 3.342 62.366 3.639 3.342 62.366 2.851 2.702 36.880 2.574 142 5.856 84.365 3.697 3.363 62.548 3.697 3.363 62.548 2.875 2.722 37.162 2.606 143 5.888 85.245 3.754 3.383 62.729 3.754 3.383 62.729 2.900 2.742 37.444 2.638 144 5.920 86.124 3.811 3.404 62.910 3.811 3.404 62.910 2.925 2.762 37.727 2.671 145 5.951 87.003 3.869 3.425 63.091 3.869 3.425 63.091 2.949 2.782 38.009 2.703 146 5.975 87.915 3.892 3.453 63.539 3.892 3.453 63.539 2.959 2.797 38.632 2.715 147 5.998 88.827 3.916 3.482 63.987 3.916 3.482 63.987 2.968 2.811 39.255 2.726 148 6.022 89.739 3.939 3.510 64.435 3.939 3.510 64.435 2.978 2.825 39.878 2.738 149 6.046 90.652 3.963 3.539 64.883 3.963 3.539 64.883 2.987 2.839 40.501 2.750 150 6.069 91.564 3.986 3.568 65.331 3.986 3.568 65.331 2.997 2.853 41.124 2.762 151 6.099 92.475 4.000 3.595 65.704 4.000 3.595 65.704 3.007 2.868 41.450 2.774 152 6.129 93.387 4.014 3.623 66.077 4.014 3.623 66.077 3.017 2.883 41.776 2.786 153 6.159 94.298 4.029 3.650 66.450 4.029 3.650 66.450 3.028 2.898 42.102 2.799 154 6.189 95.209 4.043 3.677 66.823 4.043 3.677 66.823 3.038 2.913 42.428 2.811 155 6.219 96.121 4.057 3.705 67.197 4.057 3.705 67.197 3.049 2.927 42.754 2.823 156 6.313 97.599 4.117 3.767 69.206 4.117 3.767 69.206 3.113 2.969 44.233 2.870 157 6.407 99.077 4.176 3.829 71.215 4.176 3.829 71.215 3.178 3.011 45.712 2.917 158 6.501 100.555 4.236 3.891 73.225 4.236 3.891 73.225 3.242 3.053 47.191 2.96465 159 6.595 102.033 4.295 3.953 75.234 4.295 3.953 75.234 3.307 3.095 48.670 3.011 160 6.689 103.511 4.355 4.015 77.243 4.355 4.015 77.243 3.371 3.136 50.149 3.057 161 7.010 107.552 4.551 4.078 79.985 4.551 4.078 79.985 3.503 3.182 51.569 3.181 162 7.331 111.593 4.747 4.142 82.727 4.747 4.142 82.727 3.635 3.227 52.988 3.306 163 7.652 115.634 4.943 4.205 85.469 4.943 4.205 85.469 3.767 3.272 54.408 3.430 164 7.972 119.676 5.139 4.268 88.211 5.139 4.268 88.211 3.899 3.318 55.828 3.554 165 8.293 123.717 5.335 4.332 90.953 5.335 4.332 90.953 4.030 3.363 57.247 3.678 166 8.671 125.252 5.516 4.380 93.266 5.516 4.380 93.266 4.145 3.410 58.958 3.796 167 9.050 126.786 5.696 4.428 95.579 5.696 4.428 95.579 4.260 3.458 60.670 3.914 168 9.428 128.321 5.876 4.477 97.892 5.876 4.477 97.892 4.375 3.505 62.381 4.033 169 9.806 129.855 6.056 4.525 100.205 6.056 4.525 100.205 4.490 3.552 64.092 4.151 170 10.184 131.390 6.237 4.573 102.517 6.237 4.573 102.517 4.605 3.600 65.804 4.269 171 10.426 132.095 6.345 4.618 103.813 6.345 4.618 103.813 4.673 3.644 66.939 4.322 172 10.667 132.801 6.452 4.664 105.109 6.452 4.664 105.109 4.741 3.688 68.075 4.374 173 10.909 133.506 6.560 4.709 106.404 6.560 4.709 106.404 4.808 3.732 69.210 4.426 174 11.150 134.211 6.668 4.754 107.700 6.668 4.754 107.700 4.876 3.776 70.345 4.479 175 11.392 134.917 6.776 4.799 108.995 6.776 4.799 108.995 4.944 3.821 71.481 4.531 176 11.439 137.703 6.910 4.858 110.733 6.910 4.858 110.733 5.057 3.856 73.077 4.626 177 11.486 140.490 7.045 4.917 112.471 7.045 4.917 112.471 5.171 3.891 74.674 4.722 178 11.533 143.276 7.179 4.977 114.209 7.179 4.977 114.209 5.284 3.927 76.271 4.817 179 11.581 146.063 7.313 5.036 115.946 7.313 5.036 115.946 5.398 3.962 77.867 4.912 180 11.628 148.849 7.447 5.095 117.684 7.447 5.095 117.684 5.511 3.997 79.464 5.008 181 11.671 154.282 7.621 5.158 119.775 7.621 5.158 119.775 5.641 4.024 81.282 5.111 182 11.715 159.715 7.795 5.221 121.866 7.795 5.221 121.866 5.770 4.050 83.100 5.214 183 11.759 165.147 7.969 5.284 123.956 7.969 5.284 123.956 5.900 4.077 84.919 5.318 184 11.803 170.580 8.143 5.347 126.047 8.143 5.347 126.047 6.029 4.104 86.737 5.421 185 11.846 176.013 8.318 5.411 128.138 8.318 5.411 128.138 6.159 4.131 88.555 5.524 186 11.887 179.970 8.499 5.428 129.673 8.499 5.428 129.673 6.285 4.154 90.333 5.656 187 11.928 183.927 8.681 5.446 131.209 8.681 5.446 131.209 6.411 4.178 92.110 5.787 188 11.969 187.884 8.862 5.463 132.745 8.862 5.463 132.745 6.537 4.202 93.888 5.919 189 12.010 191.841 9.043 5.481 134.281 9.043 5.481 134.281 6.663 4.225 95.665 6.050 190 12.051 195.798 9.225 5.499 135.816 9.225 5.499 135.816 6.789 4.249 97.442 6.182 191 12.090 197.691 9.386 5.561 137.198 9.386 5.561 137.198 6.875 4.285 98.856 6.266 192 12.128 199.584 9.547 5.623 138.580 9.547 5.623 138.580 6.961 4.321 100.271 6.350 193 12.166 201.476 9.708 5.686 139.961 9.708 5.686 139.961 7.047 4.357 101.685 6.435 194 12.205 203.369 9.869 5.748 141.343 9.869 5.748 141.343 7.133 4.393 103.099 6.519 195 12.243 205.262 10.030 5.810 142.724 10.030 5.810 142.724 7.219 4.430 104.513 6.603 196 12.281 208.341 10.188 5.828 144.052 10.188 5.828 144.052 7.346 4.460 106.134 6.706 197 12.319 211.419 10.346 5.845 145.381 10.346 5.845 145.381 7.473 4.490 107.755 6.810 198 12.357 214.498 10.504 5.863 146.709 10.504 5.863 146.709 7.600 4.520 109.376 6.913 199 12.395 217.577 10.662 5.880 148.037 10.662 5.880 148.037 7.727 4.550 110.997 7.017 200 12.433 220.656 10.820 5.898 149.365 10.820 5.898 149.365 7.853 4.580 112.617 7.120 201 12.509 221.810 10.948 5.942 150.214 10.948 5.942 150.214 7.929 4.623 113.207 7.195 202 12.585 222.965 11.075 5.986 151.063 11.075 5.986 151.063 8.005 4.666 113.796 7.270 203 12.661 224.119 11.203 6.029 151.912 11.203 6.029 151.912 8.080 4.709 114.385 7.34566 204 12.738 225.274 11.330 6.073 152.760 11.330 6.073 152.760 8.156 4.752 114.974 7.419 205 12.814 226.429 11.458 6.117 153.609 11.458 6.117 153.609 8.232 4.795 115.563 7.494 206 12.891 228.364 11.530 6.174 154.888 11.530 6.174 154.888 8.295 4.848 116.847 7.544 207 12.969 230.299 11.601 6.231 156.166 11.601 6.231 156.166 8.357 4.901 118.131 7.594 208 13.046 232.235 11.673 6.288 157.445 11.673 6.288 157.445 8.420 4.955 119.415 7.644 209 13.124 234.170 11.745 6.345 158.724 11.745 6.345 158.724 8.483 5.008 120.699 7.694 210 13.201 236.105 11.817 6.401 160.002 11.817 6.401 160.002 8.545 5.061 121.983 7.744 211 13.233 239.385 11.984 6.451 161.606 11.984 6.451 161.606 8.670 5.090 123.498 7.846 212 13.264 242.664 12.152 6.500 163.210 12.152 6.500 163.210 8.794 5.119 125.012 7.948 213 13.296 245.943 12.319 6.550 164.814 12.319 6.550 164.814 8.919 5.147 126.526 8.051 214 13.328 249.223 12.486 6.599 166.418 12.486 6.599 166.418 9.043 5.176 128.040 8.153 215 13.359 252.502 12.653 6.649 168.022 12.653 6.649 168.022 9.168 5.204 129.554 8.255 216 13.423 253.243 12.780 6.693 168.948 12.780 6.693 168.948 9.251 5.240 130.345 8.328 217 13.487 253.983 12.906 6.737 169.874 12.906 6.737 169.874 9.334 5.275 131.136 8.400 218 13.551 254.724 13.032 6.782 170.800 13.032 6.782 170.800 9.417 5.310 131.928 8.472 219 13.615 255.464 13.159 6.826 171.726 13.159 6.826 171.726 9.500 5.345 132.719 8.545 220 13.679 256.204 13.285 6.870 172.653 13.285 6.870 172.653 9.584 5.380 133.510 8.617 221 13.852 256.417 13.314 6.946 173.200 13.314 6.946 173.200 9.598 5.436 133.899 8.630 222 14.025 256.629 13.343 7.022 173.748 13.343 7.022 173.748 9.612 5.492 134.287 8.642 223 14.198 256.841 13.371 7.098 174.295 13.371 7.098 174.295 9.627 5.548 134.676 8.655 224 14.371 257.053 13.400 7.173 174.843 13.400 7.173 174.843 9.641 5.604 135.064 8.667 225 14.544 257.265 13.429 7.249 175.391 13.429 7.249 175.391 9.655 5.660 135.453 8.680 226 14.737 257.645 13.440 7.334 175.611 13.440 7.334 175.611 9.664 5.699 135.633 8.688 227 14.929 258.025 13.452 7.419 175.831 13.452 7.419 175.831 9.674 5.738 135.814 8.696 228 15.122 258.405 13.464 7.504 176.051 13.464 7.504 176.051 9.683 5.776 135.995 8.704 229 15.315 258.785 13.475 7.589 176.271 13.475 7.589 176.271 9.692 5.815 136.176 8.712 230 15.507 259.165 13.487 7.674 176.491 13.487 7.674 176.491 9.701 5.854 136.356 8.720 231 15.616 259.629 13.498 7.710 176.612 13.498 7.710 176.612 9.710 5.875 136.581 8.727 232 15.725 260.092 13.508 7.746 176.732 13.508 7.746 176.732 9.719 5.897 136.806 8.733 233 15.834 260.556 13.519 7.782 176.853 13.519 7.782 176.853 9.728 5.918 137.031 8.740 234 15.944 261.020 13.530 7.818 176.974 13.530 7.818 176.974 9.737 5.940 137.256 8.746 235 16.053 261.484 13.540 7.853 177.095 13.540 7.853 177.095 9.746 5.961 137.482 8.753 236 16.085 261.890 13.551 7.867 177.463 13.551 7.867 177.463 9.754 5.977 137.680 8.760 237 16.117 262.296 13.561 7.881 177.830 13.561 7.881 177.830 9.761 5.994 137.879 8.767 238 16.149 262.701 13.572 7.894 178.198 13.572 7.894 178.198 9.769 6.010 138.078 8.774 239 16.181 263.107 13.582 7.908 178.566 13.582 7.908 178.566 9.777 6.026 138.277 8.781 240 16.214 263.513 13.592 7.922 178.933 13.592 7.922 178.933 9.785 6.042 138.476 8.78867 Appendix C Fast Pass IM240 Standards Developed for Wisconsin68 Fast Pass IM240 Standards Developed for Wisconsin
Wisconsin requested EPA provide fast-pass cutpoints for final and intermediate standards. A method is outlined below. This was applied only to the Appendix. A fast-pass cutpoints but could be used on others also.

1) A scale factor for each pollutant at each second is defined. This was done to calculate the cutpoint at second i for each pollutant at each standard.
For example: HC Scale Factor for the 0.8 cutpoint
FPHC Scale Factor = [HC(0.8)Fast Pass Cutpoint at t= i ] / [HC(0.8) Fast Pass Cutpoint at t=239]

2) The ratio of the Fast Pass cutpoint at t=239 to the distance traveled (1.973 mi) was found. This was done so the new fast-pass cut points could be scaled to the new full 240 second standard
For HC (0.8g/mi):
FPHC 239 = 1.615 g 

### Distance = 1.973 mi 

### FPHC 239 g/mi = 0.81855 % above 0.8 g/mi standard = (0.818-0.8)/0.8*100 = 2.2%
For new HC standard (0.6 g/mi):
(FPHC 239 g/mi - 0.6)/0.6 * 100 = 2.2%
(This provides the same 2.2% overshoot as the phase-in fast-pass standards.)
FPHC 239 g/mi = 0.6132g/mi FPHC 239 g = 1.2098

3) The new fast pass standards will then be calculated as:
HC(0.6)FP = FP(0.6)239 * HCSF(0.8)i

t HC(0.8) 

### g FPHC SF HC(0.6) 

### g 30 0.124 0.0768 0.092969 31 0.126 0.0780 0.0944

.....
238 1.614 0.9994 1.2091 239 1.615 1.0000 1.2098

4) For Phase 2 cut points, where needed:

Take the old standard, for example, FPHC Phase 2 = 0.5 g/mi

The distance traveled from second 108 to second 239 is 1.359 mi
The old FPHC 239 cutpoint is 0.716 g
In terms of g/mi this is 0.716/1.359 = 0.527 g/mi
The delta between this value and the actual standard is: (0.527-0.5) = 0.027 g/mi
The new FPHC 239 g/mi cutpoint is: 0.4 + 0.027 = 0.427 g/mi . In terms of g, this is FPHC 239 g/mi * 1.359 mi = 0.580 g
The Scale Factor is calculated as before for each second of the test, and the Phase 2 cutpoint at each second is calculated by multiplying this Scale Factor times the new FP cutpoint in g at 239. In this case, that new FP cutpoint would be 0.580 * Scale Factor for each second.70 Hydrocarbon(g) Carbon Monoxide (g) Oxides of Nitrogen (g) Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 Composite Phase 2 Composit

e Composite Composite
Sec (0.6) (0.4) (0.8) (0.5) (1.1) (0.7) (10.0) (0.8) (15.0) (12.0) (20.0) (16.0) (1.5) (2.0) (2.5) 30 0.093 n/a 0.124 n/a 0.226 n/a 0.462 n/a 0.693 n/a 1.502 n/a 0.125 0.167 0.262 31 0.095 n/a 0.126 n/a 0.232 n/a 0.515 n/a 0.773 n/a 1.546 n/a 0.133 0.177 0.275 32 0.097 n/a 0.129 n/a 0.237 n/a 0.558 n/a 0.837 n/a 1.568 n/a 0.141 0.188 0.301 33 0.101 n/a 0.135 n/a 0.241 n/a 0.567 n/a 0.851 n/a 1.582 n/a 0.161 0.214 0.317 34 0.105 n/a 0.140 n/a 0.246 n/a 0.569 n/a 0.853 n/a 1.593 n/a 0.174 0.232 0.327 35 0.110 n/a 0.146 n/a 0.254 n/a 0.571 n/a 0.857 n/a 1.602 n/a 0.180 0.240 0.330 36 0.113 n/a 0.150 n/a 0.259 n/a 0.600 n/a 0.900 n/a 1.621 n/a 0.182 0.243 0.332 37 0.115 n/a 0.153 n/a 0.269 n/a 0.640 n/a 0.960 n/a 1.631 n/a 0.184 0.245 0.334 38 0.117 n/a 0.156 n/a 0.272 n/a 0.689 n/a 1.034 n/a 1.702 n/a 0.185 0.246 0.336 39 0.120 n/a 0.160 n/a 0.273 n/a 0.713 n/a 1.070 n/a 1.784 n/a 0.185 0.246 0.337 40 0.124 n/a 0.165 n/a 0.287 n/a 0.717 n/a 1.076 n/a 1.879 n/a 0.188 0.250 0.354 41 0.127 n/a 0.169 n/a 0.293 n/a 0.722 n/a 1.083 n/a 2.162 n/a 0.195 0.260 0.366 42 0.129 n/a 0.172 n/a 0.300 n/a 0.735 n/a 1.102 n/a 2.307 n/a 0.208 0.277 0.410 43 0.130 n/a 0.173 n/a 0.314 n/a 0.741 n/a 1.111 n/a 2.343 n/a 0.233 0.311 0.414 44 0.133 n/a 0.177 n/a 0.330 n/a 0.743 n/a 1.114 n/a 2.376 n/a 0.246 0.328 0.438 45 0.148 n/a 0.197 n/a 0.345 n/a 0.771 n/a 1.157 n/a 2.406 n/a 0.257 0.343 0.477 46 0.150 n/a 0.200 n/a 0.357 n/a 0.896 n/a 1.344 n/a 2.433 n/a 0.269 0.359 0.506 47 0.156 n/a 0.208 n/a 0.374 n/a 0.988 n/a 1.482 n/a 2.458 n/a 0.280 0.373 0.518 48 0.166 n/a 0.221 n/a 0.388 n/a 1.020 n/a 1.530 n/a 2.483 n/a 0.287 0.383 0.522 49 0.174 n/a 0.232 n/a 0.398 n/a 1.028 n/a 1.542 n/a 2.774 n/a 0.289 0.385 0.526 50 0.176 n/a 0.235 n/a 0.407 n/a 1.035 n/a 1.553 n/a 2.844 n/a 0.300 0.400 0.554 51 0.179 n/a 0.238 n/a 0.416 n/a 1.047 n/a 1.571 n/a 2.900 n/a 0.308 0.410 0.574 52 0.180 n/a 0.240 n/a 0.426 n/a 1.063 n/a 1.595 n/a 2.936 n/a 0.326 0.434 0.587 53 0.182 n/a 0.242 n/a 0.433 n/a 1.089 n/a 1.633 n/a 3.133 n/a 0.348 0.464 0.601 54 0.185 n/a 0.246 n/a 0.438 n/a 1.123 n/a 1.685 n/a 3.304 n/a 0.354 0.472 0.615 55 0.187 n/a 0.249 n/a 0.445 n/a 1.126 n/a 1.689 n/a 3.407 n/a 0.360 0.480 0.629 56 0.189 n/a 0.252 n/a 0.452 n/a 1.129 n/a 1.693 n/a 3.456 n/a 0.368 0.491 0.643 57 0.196 n/a 0.261 n/a 0.458 n/a 1.133 n/a 1.700 n/a 3.480 n/a 0.375 0.500 0.667 58 0.203 n/a 0.271 n/a 0.463 n/a 1.149 n/a 1.723 n/a 3.518 n/a 0.380 0.506 0.678 59 0.207 n/a 0.276 n/a 0.471 n/a 1.235 n/a 1.852 n/a 3.560 n/a 0.382 0.509 0.683 60 0.209 n/a 0.278 n/a 0.492 n/a 1.248 n/a 1.872 n/a 3.593 n/a 0.384 0.512 0.686 61 0.210 n/a 0.280 n/a 0.495 n/a 1.248 n/a 1.872 n/a 3.628 n/a 0.387 0.516 0.693 62 0.212 n/a 0.282 n/a 0.498 n/a 1.248 n/a 1.872 n/a 3.641 n/a 0.389 0.519 0.699 63 0.212 n/a 0.283 n/a 0.501 n/a 1.267 n/a 1.900 n/a 3.655 n/a 0.392 0.523 0.703 64 0.213 n/a 0.284 n/a 0.505 n/a 1.278 n/a 1.917 n/a 3.680 n/a 0.397 0.529 0.707 65 0.214 n/a 0.285 n/a 0.512 n/a 1.296 n/a 1.944 n/a 3.700 n/a 0.400 0.533 0.711 66 0.215 n/a 0.286 n/a 0.520 n/a 1.333 n/a 2.000 n/a 3.728 n/a 0.401 0.535 0.716 67 0.216 n/a 0.288 n/a 0.527 n/a 1.373 n/a 2.060 n/a 3.857 n/a 0.405 0.540 0.721 68 0.218 n/a 0.291 n/a 0.539 n/a 1.376 n/a 2.064 n/a 3.894 n/a 0.413 0.551 0.726 69 0.221 n/a 0.294 n/a 0.545 n/a 1.384 n/a 2.076 n/a 3.943 n/a 0.422 0.563 0.742 70 0.222 n/a 0.296 n/a 0.551 n/a 1.403 n/a 2.104 n/a 3.983 n/a 0.431 0.575 0.759 71 0.224 n/a 0.298 n/a 0.556 n/a 1.411 n/a 2.117 n/a 4.009 n/a 0.441 0.588 0.773 72 0.225 n/a 0.300 n/a 0.559 n/a 1.417 n/a 2.125 n/a 4.023 n/a 0.450 0.600 0.784 73 0.227 n/a 0.302 n/a 0.566 n/a 1.420 n/a 2.130 n/a 4.023 n/a 0.452 0.603 0.790 74 0.228 n/a 0.304 n/a 0.578 n/a 1.425 n/a 2.138 n/a 4.053 n/a 0.453 0.604 0.794 75 0.230 n/a 0.307 n/a 0.589 n/a 1.435 n/a 2.152 n/a 4.063 n/a 0.460 0.613 0.799 76 0.231 n/a 0.308 n/a 0.597 n/a 1.447 n/a 2.170 n/a 4.077 n/a 0.468 0.624 0.809 77 0.231 n/a 0.308 n/a 0.604 n/a 1.459 n/a 2.188 n/a 4.225 n/a 0.485 0.646 0.82171 78 0.231 n/a 0.308 n/a 0.611 n/a 1.467 n/a 2.200 n/a 4.243 n/a 0.488 0.651 0.833 79 0.236 n/a 0.314 n/a 0.620 n/a 1.475 n/a 2.212 n/a 4.260 n/a 0.494 0.659 0.839 80 0.240 n/a 0.320 n/a 0.624 n/a 1.475 n/a 2.212 n/a 4.282 n/a 0.505 0.673 0.844 81 0.243 n/a 0.324 n/a 0.628 n/a 1.481 n/a 2.221 n/a 4.322 n/a 0.522 0.696 0.857 82 0.245 n/a 0.327 n/a 0.632 n/a 1.481 n/a 2.222 n/a 4.398 n/a 0.530 0.706 0.870 83 0.247 n/a 0.329 n/a 0.636 n/a 1.485 n/a 2.227 n/a 4.482 n/a 0.536 0.715 0.883 84 0.250 n/a 0.333 n/a 0.642 n/a 1.491 n/a 2.236 n/a 4.515 n/a 0.543 0.724 0.894 85 0.252 n/a 0.336 n/a 0.646 n/a 1.495 n/a 2.243 n/a 4.518 n/a 0.553 0.737 0.902 86 0.254 n/a 0.339 n/a 0.650 n/a 1.508 n/a 2.262 n/a 4.520 n/a 0.560 0.747 0.907 87 0.257 n/a 0.343 n/a 0.654 n/a 1.514 n/a 2.271 n/a 4.522 n/a 0.561 0.748 0.910 88 0.260 n/a 0.347 n/a 0.657 n/a 1.523 n/a 2.284 n/a 4.522 n/a 0.561 0.748 0.912 89 0.263 n/a 0.350 n/a 0.661 n/a 1.533 n/a 2.299 n/a 4.523 n/a 0.561 0.748 0.913 90 0.267 n/a 0.356 n/a 0.664 n/a 1.539 n/a 2.308 n/a 4.526 n/a 0.561 0.748 0.914 91 0.269 n/a 0.358 n/a 0.666 n/a 1.551 n/a 2.326 n/a 4.527 n/a 0.561 0.748 0.915 92 0.270 n/a 0.360 n/a 0.668 n/a 1.553 n/a 2.330 n/a 4.527 n/a 0.561 0.748 0.916 93 0.272 n/a 0.363 n/a 0.670 n/a 1.554 n/a 2.331 n/a 4.528 n/a 0.561 0.748 0.917 94 0.275 n/a 0.367 n/a 0.673 n/a 1.563 n/a 2.344 n/a 4.528 n/a 0.561 0.748 0.918 95 0.278 n/a 0.370 n/a 0.678 n/a 1.565 n/a 2.347 n/a 4.528 n/a 0.561 0.748 0.919 96 0.279 n/a 0.372 n/a 0.686 n/a 1.570 n/a 2.355 n/a 4.529 n/a 0.561 0.748 0.920 97 0.282 n/a 0.376 n/a 0.696 n/a 1.597 n/a 2.395 n/a 4.575 n/a 0.561 0.748 0.921 98 0.291 n/a 0.388 n/a 0.707 n/a 1.634 n/a 2.451 n/a 4.703 n/a 0.561 0.748 0.922 99 0.297 n/a 0.396 n/a 0.718 n/a 1.672 n/a 2.508 n/a 4.805 n/a 0.563 0.751 0.924 100 0.304 n/a 0.405 n/a 0.727 n/a 1.727 n/a 2.590 n/a 4.886 n/a 0.573 0.764 0.929 101 0.308 n/a 0.410 n/a 0.743 n/a 1.773 n/a 2.660 n/a 4.957 n/a 0.592 0.789 0.941 102 0.308 n/a 0.411 n/a 0.754 n/a 1.833 n/a 2.749 n/a 5.104 n/a 0.617 0.822 0.970 103 0.309 n/a 0.412 n/a 0.766 n/a 1.942 n/a 2.913 n/a 5.340 n/a 0.650 0.867 1.027 104 0.310 n/a 0.413 n/a 0.782 n/a 2.108 n/a 3.162 n/a 5.496 n/a 0.679 0.905 1.093 105 0.316 n/a 0.421 n/a 0.798 n/a 2.113 n/a 3.170 n/a 5.625 n/a 0.694 0.925 1.155 106 0.321 n/a 0.428 n/a 0.813 n/a 2.131 n/a 3.197 n/a 5.815 n/a 0.716 0.955 1.234 107 0.323 n/a 0.430 n/a 0.824 n/a 2.192 n/a 3.288 n/a 6.473 n/a 0.739 0.985 1.275 108 0.341 n/a 0.455 n/a 0.853 n/a 2.279 n/a 3.419 n/a 7.037 n/a 0.745 0.993 1.305 109 0.344 0.012 0.459 0.015 0.868 0.037 2.391 0.115 3.587 0.168 7.419 0.246 0.746 0.995 1.320 110 0.347 0.014 0.462 0.017 0.877 0.044 2.397 0.119 3.595 0.173 7.643 0.257 0.747 0.996 1.332 111 0.348 0.017 0.464 0.021 0.885 0.049 2.427 0.163 3.640 0.237 7.759 0.286 0.758 1.010 1.346 112 0.350 0.019 0.466 0.024 0.890 0.052 2.493 0.183 3.740 0.266 7.824 0.379 0.771 1.028 1.358 113 0.351 0.019 0.468 0.024 0.896 0.057 2.579 0.192 3.868 0.280 7.889 0.425 0.776 1.034 1.378 114 0.353 0.020 0.471 0.025 0.901 0.060 2.585 0.200 3.877 0.291 7.960 0.457 0.783 1.044 1.406 115 0.366 0.021 0.488 0.026 0.919 0.067 2.623 0.216 3.934 0.314 8.024 0.477 0.794 1.059 1.426 116 0.385 0.023 0.513 0.029 0.944 0.076 2.677 0.227 4.015 0.331 8.076 0.494 0.806 1.075 1.438 117 0.404 0.026 0.538 0.032 0.954 0.077 2.707 0.237 4.061 0.345 8.111 0.504 0.810 1.080 1.448 118 0.421 0.028 0.561 0.035 0.963 0.078 2.709 0.240 4.063 0.350 8.130 0.512 0.810 1.080 1.460 119 0.433 0.028 0.577 0.035 0.964 0.086 2.719 0.245 4.079 0.356 8.148 0.519 0.811 1.081 1.462 120 0.435 0.029 0.580 0.036 0.967 0.088 2.760 0.252 4.140 0.367 8.211 0.529 0.818 1.091 1.467 121 0.440 0.031 0.586 0.038 0.973 0.091 2.790 0.267 4.185 0.388 8.478 0.529 0.822 1.096 1.476 122 0.446 0.032 0.594 0.040 0.982 0.094 2.799 0.280 4.199 0.407 8.548 0.530 0.833 1.111 1.494 123 0.452 0.033 0.603 0.041 0.991 0.096 2.803 0.318 4.205 0.463 8.561 0.531 0.842 1.122 1.505 124 0.458 0.034 0.610 0.042 1.000 0.099 2.808 0.330 4.212 0.480 8.568 0.532 0.851 1.135 1.517 125 0.461 0.034 0.615 0.042 1.010 0.101 2.821 0.348 4.232 0.506 8.572 0.533 0.854 1.138 1.546 126 0.468 0.034 0.624 0.042 1.018 0.103 2.865 0.356 4.298 0.518 8.584 0.548 0.854 1.139 1.569 127 0.471 0.036 0.628 0.045 1.023 0.105 2.896 0.359 4.344 0.522 8.592 0.610 0.854 1.139 1.586 128 0.474 0.037 0.632 0.046 1.028 0.107 2.907 0.361 4.361 0.525 8.596 0.614 0.854 1.139 1.596 129 0.478 0.037 0.637 0.046 1.031 0.109 2.911 0.363 4.366 0.528 8.597 0.622 0.854 1.139 1.603 130 0.481 0.040 0.641 0.049 1.034 0.111 2.913 0.364 4.369 0.530 8.601 0.631 0.854 1.139 1.60572 131 0.482 0.041 0.643 0.050 1.036 0.112 2.915 0.364 4.372 0.530 8.605 0.640 0.854 1.139 1.606 132 0.483 0.042 0.644 0.052 1.038 0.114 2.957 0.367 4.435 0.534 8.608 0.646 0.854 1.139 1.607 133 0.484 0.044 0.645 0.054 1.040 0.115 3.015 0.378 4.523 0.550 8.626 0.650 0.854 1.139 1.607 134 0.485 0.044 0.647 0.054 1.040 0.116 3.016 0.381 4.524 0.554 8.650 0.652 0.854 1.139 1.608 135 0.488 0.044 0.651 0.054 1.048 0.119 3.017 0.405 4.525 0.590 8.660 0.738 0.854 1.139 1.614 136 0.494 0.045 0.658 0.055 1.051 0.122 3.021 0.423 4.531 0.616 8.767 0.754 0.870 1.160 1.616 137 0.497 0.045 0.663 0.055 1.060 0.126 3.023 0.439 4.534 0.639 9.029 0.780 0.881 1.174 1.631 138 0.500 0.045 0.666 0.056 1.066 0.130 3.028 0.449 4.542 0.653 9.238 0.795 0.887 1.183 1.643 139 0.501 0.048 0.668 0.059 1.087 0.137 3.035 0.455 4.553 0.662 9.389 0.804 0.898 1.197 1.656 140 0.503 0.049 0.670 0.061 1.149 0.140 3.036 0.469 4.554 0.683 9.493 0.810 0.917 1.223 1.673 141 0.504 0.049 0.672 0.061 1.157 0.141 3.036 0.478 4.554 0.696 9.583 0.815 0.941 1.255 1.703 142 0.506 0.049 0.675 0.061 1.165 0.143 3.036 0.486 4.554 0.708 9.626 0.818 0.954 1.272 1.739 143 0.509 0.051 0.678 0.063 1.171 0.145 3.036 0.495 4.554 0.721 9.669 0.821 0.965 1.286 1.767 144 0.511 0.052 0.681 0.064 1.176 0.147 3.036 0.508 4.554 0.739 9.716 0.825 0.978 1.304 1.774 145 0.513 0.053 0.684 0.065 1.183 0.152 3.036 0.510 4.554 0.742 9.763 0.840 0.980 1.307 1.785 146 0.515 0.053 0.686 0.066 1.186 0.154 3.036 0.510 4.554 0.743 9.809 0.847 0.984 1.312 1.806 147 0.516 0.054 0.688 0.067 1.188 0.156 3.036 0.512 4.554 0.745 9.852 0.855 0.988 1.317 1.830 148 0.518 0.055 0.690 0.068 1.190 0.157 3.036 0.514 4.554 0.748 9.885 0.865 0.991 1.321 1.844 149 0.519 0.056 0.692 0.069 1.194 0.158 3.036 0.516 4.554 0.751 9.932 0.874 0.994 1.325 1.845 150 0.521 0.057 0.694 0.070 1.206 0.159 3.036 0.524 4.554 0.762 9.986 0.891 0.996 1.328 1.846 151 0.522 0.058 0.696 0.071 1.219 0.160 3.037 0.542 4.556 0.789 10.039 0.914 0.999 1.332 1.852 152 0.524 0.058 0.698 0.072 1.230 0.161 3.037 0.543 4.556 0.790 10.072 0.929 1.004 1.338 1.868 153 0.525 0.059 0.700 0.073 1.236 0.162 3.043 0.546 4.565 0.794 10.090 0.937 1.008 1.344 1.877 154 0.527 0.059 0.702 0.073 1.240 0.164 3.075 0.549 4.612 0.799 10.105 0.942 1.013 1.350 1.879 155 0.528 0.060 0.704 0.074 1.249 0.167 3.223 0.553 4.834 0.805 10.146 0.949 1.018 1.357 1.886 156 0.530 0.062 0.706 0.077 1.251 0.169 3.801 0.578 5.702 0.842 10.245 1.375 1.024 1.365 1.900 157 0.531 0.064 0.708 0.079 1.252 0.177 3.894 0.680 5.841 0.990 10.397 1.576 1.034 1.379 1.910 158 0.533 0.066 0.710 0.082 1.259 0.185 4.113 0.713 6.170 1.038 10.923 1.943 1.061 1.414 1.936 159 0.534 0.066 0.712 0.082 1.281 0.190 4.447 0.932 6.670 1.357 11.970 2.820 1.100 1.466 1.954 160 0.537 0.070 0.716 0.086 1.304 0.194 4.950 1.000 7.425 1.455 13.421 3.281 1.136 1.514 1.986 161 0.563 0.077 0.750 0.095 1.320 0.200 5.586 1.062 8.379 1.546 15.289 3.483 1.169 1.559 2.050 162 0.588 0.087 0.784 0.107 1.331 0.207 6.432 1.253 9.648 1.824 15.912 3.620 1.193 1.591 2.131 163 0.604 0.093 0.805 0.115 1.343 0.215 7.279 1.887 10.918 2.746 16.530 4.168 1.231 1.641 2.235 164 0.630 0.099 0.840 0.122 1.383 0.231 8.105 2.111 12.157 3.073 17.622 4.338 1.289 1.719 2.320 165 0.640 0.103 0.853 0.127 1.405 0.257 8.487 2.496 12.731 3.633 18.366 4.682 1.333 1.777 2.395 166 0.656 0.129 0.874 0.159 1.425 0.289 8.554 3.095 12.831 4.505 19.869 5.633 1.374 1.832 2.488 167 0.677 0.151 0.903 0.186 1.445 0.298 8.595 3.402 12.892 4.952 20.711 6.137 1.439 1.919 2.563 168 0.683 0.153 0.910 0.189 1.465 0.302 8.621 3.610 12.932 5.254 22.319 6.853 1.479 1.972 2.645 169 0.686 0.162 0.914 0.200 1.483 0.312 9.135 3.937 13.702 5.730 23.751 7.136 1.510 2.013 2.746 170 0.687 0.178 0.916 0.220 1.500 0.321 9.426 4.157 14.139 6.051 24.842 7.320 1.575 2.100 2.778 171 0.689 0.191 0.919 0.236 1.527 0.333 9.976 4.351 14.964 6.333 25.410 7.685 1.650 2.200 2.792 172 0.698 0.200 0.931 0.247 1.545 0.361 10.469 4.459 15.704 6.490 25.798 8.052 1.688 2.251 2.810 173 0.711 0.208 0.948 0.257 1.582 0.383 10.835 4.669 16.253 6.796 26.122 8.344 1.703 2.270 2.847 174 0.737 0.216 0.983 0.267 1.597 0.406 11.271 4.950 16.907 7.205 26.353 8.602 1.726 2.301 2.874 175 0.764 0.229 1.018 0.283 1.610 0.424 11.770 5.600 17.655 8.151 26.638 8.898 1.739 2.318 2.905 176 0.770 0.239 1.027 0.295 1.622 0.434 12.013 5.654 18.020 8.230 27.219 9.251 1.751 2.335 2.950 177 0.776 0.253 1.035 0.312 1.635 0.475 12.233 5.898 18.349 8.584 27.279 10.253 1.762 2.349 3.001 178 0.788 0.258 1.051 0.318 1.652 0.490 12.447 6.046 18.671 8.800 27.320 10.828 1.790 2.387 3.047 179 0.806 0.262 1.074 0.323 1.670 0.495 12.648 6.078 18.972 8.847 27.352 10.933 1.817 2.423 3.104 180 0.813 0.273 1.084 0.337 1.689 0.507 12.819 6.124 19.228 8.913 27.822 11.060 1.847 2.462 3.173 181 0.824 0.280 1.099 0.345 1.709 0.514 13.415 6.267 20.123 9.122 28.763 11.188 1.877 2.503 3.238 182 0.841 0.284 1.121 0.350 1.727 0.524 13.603 6.549 20.405 9.532 29.402 11.345 1.909 2.545 3.302 183 0.849 0.291 1.132 0.359 1.738 0.535 13.836 7.046 20.754 10.256 29.971 11.733 1.940 2.586 3.37273 184 0.864 0.314 1.152 0.387 1.755 0.547 14.456 7.463 21.684 10.862 30.276 12.598 1.970 2.627 3.452 185 0.871 0.322 1.161 0.398 1.778 0.560 14.637 7.555 21.955 10.996 30.988 12.953 2.005 2.673 3.545 186 0.876 0.324 1.168 0.400 1.795 0.574 15.100 7.699 22.650 11.206 31.095 13.213 2.062 2.749 3.648 187 0.881 0.326 1.175 0.402 1.808 0.585 15.326 7.911 22.989 11.514 31.314 14.131 2.103 2.804 3.701 188 0.886 0.328 1.181 0.405 1.820 0.589 15.690 8.172 23.535 11.894 31.833 14.839 2.138 2.851 3.759 189 0.891 0.339 1.188 0.418 1.825 0.589 15.917 8.258 23.876 12.019 32.239 15.137 2.171 2.894 3.821 190 0.902 0.348 1.203 0.429 1.827 0.598 16.012 8.361 24.018 12.170 32.547 15.138 2.198 2.931 3.870 191 0.914 0.358 1.219 0.442 1.829 0.607 16.309 8.600 24.464 12.517 32.855 15.141 2.228 2.971 3.892 192 0.925 0.370 1.233 0.457 1.834 0.617 16.457 8.655 24.685 12.598 33.153 15.595 2.265 3.020 3.914 193 0.938 0.383 1.251 0.473 1.847 0.621 16.621 8.674 24.931 12.625 33.444 15.658 2.308 3.077 3.955 194 0.941 0.395 1.255 0.487 1.862 0.629 16.792 8.693 25.188 12.653 33.482 15.704 2.349 3.132 3.997 195 0.944 0.406 1.258 0.501 1.876 0.638 16.979 8.778 25.468 12.777 33.516 15.729 2.389 3.185 4.035 196 0.949 0.413 1.265 0.510 1.891 0.649 17.085 8.867 25.627 12.906 33.549 16.058 2.414 3.219 4.089 197 0.960 0.415 1.280 0.512 1.906 0.664 17.164 8.924 25.746 12.989 33.653 16.987 2.451 3.268 4.146 198 0.970 0.416 1.293 0.514 1.920 0.679 17.233 8.973 25.850 13.060 33.973 17.064 2.474 3.299 4.206 199 0.976 0.418 1.301 0.516 1.933 0.693 17.316 9.045 25.974 13.165 34.159 17.073 2.513 3.350 4.243 200 0.985 0.420 1.313 0.518 1.945 0.706 17.427 9.098 26.141 13.242 34.191 17.153 2.555 3.406 4.295 201 0.993 0.427 1.324 0.527 1.953 0.719 17.483 9.215 26.225 13.412 34.250 17.332 2.600 3.466 4.351 202 0.999 0.438 1.332 0.540 1.959 0.726 17.559 9.386 26.338 13.662 34.469 17.406 2.623 3.497 4.398 203 1.006 0.443 1.341 0.547 1.977 0.737 17.698 9.463 26.547 13.773 34.716 17.641 2.636 3.514 4.410 204 1.018 0.448 1.357 0.553 1.991 0.745 17.879 9.579 26.818 13.942 34.969 17.922 2.638 3.517 4.419 205 1.031 0.453 1.375 0.559 2.011 0.752 18.035 9.680 27.052 14.090 35.144 18.484 2.639 3.519 4.426 206 1.044 0.456 1.392 0.563 2.037 0.800 18.262 9.773 27.393 14.224 35.418 18.553 2.642 3.523 4.429 207 1.056 0.459 1.408 0.567 2.058 0.805 18.334 9.911 27.501 14.426 35.766 18.658 2.659 3.545 4.453 208 1.067 0.463 1.422 0.571 2.079 0.817 18.421 9.961 27.632 14.498 35.949 18.953 2.678 3.570 4.486 209 1.075 0.466 1.433 0.575 2.089 0.836 18.535 10.152 27.803 14.776 36.010 19.266 2.700 3.600 4.542 210 1.082 0.469 1.443 0.579 2.097 0.839 18.635 10.242 27.953 14.907 36.548 19.309 2.714 3.619 4.598 211 1.090 0.482 1.453 0.595 2.109 0.846 18.803 10.248 28.205 14.916 37.179 19.731 2.729 3.639 4.638 212 1.097 0.490 1.463 0.605 2.123 0.866 19.029 10.315 28.543 15.014 37.651 19.902 2.765 3.686 4.715 213 1.101 0.497 1.468 0.614 2.138 0.879 19.331 10.458 28.997 15.221 38.041 20.012 2.799 3.732 4.774 214 1.103 0.504 1.470 0.622 2.150 0.882 19.333 10.630 29.000 15.472 38.591 20.260 2.843 3.791 4.829 215 1.106 0.508 1.474 0.627 2.158 0.891 19.337 10.687 29.005 15.555 38.852 20.739 2.875 3.833 4.872 216 1.109 0.517 1.478 0.638 2.165 0.905 19.387 10.754 29.081 15.652 38.861 21.346 2.918 3.890 4.931 217 1.111 0.521 1.481 0.643 2.171 0.917 19.521 10.971 29.281 15.969 38.926 21.810 2.949 3.932 4.960 218 1.113 0.521 1.484 0.643 2.178 0.918 19.655 11.012 29.483 16.028 39.194 22.001 2.970 3.960 4.963 219 1.115 0.523 1.487 0.645 2.185 0.919 19.823 11.250 29.734 16.375 39.474 22.290 2.998 3.997 4.965 220 1.118 0.527 1.490 0.651 2.192 0.941 19.869 11.327 29.803 16.487 39.668 22.324 3.010 4.013 4.968 221 1.120 0.531 1.493 0.655 2.195 0.952 19.881 11.353 29.821 16.524 39.781 22.343 3.026 4.035 4.971 222 1.128 0.537 1.504 0.663 2.200 0.957 19.898 11.390 29.847 16.578 39.890 22.522 3.029 4.038 4.974 223 1.142 0.544 1.522 0.671 2.205 0.963 19.908 11.463 29.862 16.684 39.954 22.661 3.038 4.050 4.977 224 1.160 0.547 1.547 0.675 2.208 0.970 19.915 11.511 29.873 16.755 39.984 22.666 3.050 4.066 4.979 225 1.162 0.554 1.549 0.684 2.212 0.975 20.005 11.522 30.008 16.770 39.989 22.667 3.053 4.070 4.980 226 1.172 0.562 1.562 0.694 2.214 0.979 20.084 11.546 30.126 16.805 39.990 22.668 3.054 4.072 4.981 227 1.181 0.568 1.574 0.701 2.216 0.985 20.085 11.587 30.127 16.865 39.990 22.669 3.054 4.072 4.982 228 1.184 0.569 1.579 0.702 2.217 0.988 20.085 11.652 30.127 16.960 39.990 22.670 3.055 4.073 4.983 229 1.188 0.574 1.584 0.708 2.218 0.992 20.139 11.652 30.208 16.960 39.991 22.671 3.055 4.073 4.984 230 1.192 0.574 1.589 0.708 2.219 0.995 20.209 11.654 30.314 16.962 40.012 22.671 3.055 4.073 4.985 231 1.193 0.574 1.590 0.709 2.221 0.996 20.215 11.672 30.323 16.988 40.061 22.672 3.055 4.073 4.986 232 1.197 0.575 1.596 0.710 2.223 0.996 20.217 11.729 30.325 17.072 40.116 22.673 3.056 4.074 4.987 233 1.199 0.575 1.598 0.710 2.225 0.996 20.245 11.744 30.368 17.094 40.249 22.673 3.056 4.074 4.988 234 1.203 0.576 1.604 0.711 2.227 0.997 20.274 11.806 30.411 17.184 40.253 22.673 3.056 4.075 4.989 235 1.208 0.577 1.610 0.712 2.228 0.997 20.277 11.808 30.416 17.187 40.290 22.674 3.056 4.075 4.990 236 1.209 0.577 1.612 0.712 2.228 0.999 20.285 11.809 30.428 17.188 40.385 22.675 3.057 4.076 4.99174 237 1.210 0.577 1.613 0.712 2.229 1.001 20.287 11.810 30.430 17.189 40.488 22.675 3.057 4.076 4.992 238 1.211 0.578 1.614 0.713 2.230 1.004 20.301 11.845 30.452 17.241 40.720 22.675 3.057 4.076 4.993 239 1.211 0.580 1.615 0.716 2.231 1.007 20.325 11.934 30.488 17.370 40.763 22.677 3.057 4.076 4.99475 Appendix D Fast Pass IM240 Standards: Modal Regression Technique
Developed by Sierra Research Contract 68-C4-0056 Work Assignment 2-0476 Fast Pass IM240 Standards: Modal Regression Technique

Sierra Research Contract 68-C4-0056 Work Assignment 2-04
Development of Fast-Pass Standards
This method differs from those presented in Appendices A, B, and C in that second-by-second standards are not used, rather the second-by-second emissions are used to project a final IM240 score which is then compared to the appropriate IM240 standard as listed on pages 1-4 of this document. A sample of the regression coefficients used to project the full IM240 score s are presented in this appendix. The complete set of coefficients, including an example calculation, can be downloaded from the EPA web site.
Full-duration, second-by-second IM240 data collected in the Arizona I/M program were used for this analysis. Nearly 110,000 individual tests were in the database used in the analysis, which is comprised of all full-duration IM240 tests conduct ed in Arizona from April 1995 through April 1997. Regression coefficients were generated separately for light-duty gasoline vehicles (i.e., passenger cars) and light-duty trucks for the following model year groups listed below.

 1981 to 1984,

 1985 to 1989, and

 1990 and later.

Regression coefficients were developed for HC, CO, and NOx and for both the composite IM240 and for Phase 2 of the IM240 after dividing the IM240 drive trace into 24 separate modes. The Phase 2 regressions used mode 11 as the first mode and continued through mode 23. The composite IM240 regressions used modes 1 through 23. (Although the trace was divided into 24 modes, if a fast-pass decision is not made by mode 23, then the vehicle would run the full IM240. At that point, a pass/fail decision should be made on the actual IM240 score, not the predicted score.) Finally, it is recommended that the fir st mode at which a pass/fail decision should be made is mode 4 (which ends at second 32 of the IM240) for a composite IM240 prediction, or mode 13 (which ends at second 113 of the IM240) for a Phase 2 prediction.
The regression coefficients for a 0.8 g/mi HC composite IM240 cutpoint are given in this appendix, along with the coefficients for a 0.5 g/mi HC Phase 2 IM240 cutpoint. The full series of regression coefficients developed in this effort wer e provided to EPA electronically, and are available on the OMS web page.
Using the 2% Random Sample from the Arizona program (which consists of 26,000 records), pass/fail rates were calculated with the modal regression procedures outlined above as well as the current fast-pass cutpoint tables. This analysis was performed using the final IM240 HC, CO, and NOx standards, and the results are presented in Table D1.
As observed in Table D1, the revised fast-pass methodology results in a lower fraction of false passes than the current method, particularly for older cars. However, this improvement in failing vehicle identification is offset by a longer average test time for passing vehicles in the older model year groups. For newer vehicles (i.e., 1990 and later), the revised methodology results in significant improvements in average test time, without a significant increase in the fraction of false passes.77 Table D1 Comparison of Current and Revised Fast-Pass Methodologies Under the Final IM240 Standards (26,000 Vehicle Sample) Vehicle Class Model Year Group "True" Failure Rate a Current Fast-Pass Revised Fast-Pass

Failure Rate Pass Time (seconds) Failure Rate Pass Time (seconds) LDV 81 - 84 79% 76% 125 78% 157 85 - 89 45% 41% 130 43% 121 1990+ 8% 7% 88 7% 57 LDT 81 - 84 62% 51% 71 60% 113 85 - 89 42% 35% 70 40% 93 1990+ 9% 7% 60 7% 57

a

The "true" failure rate is based on full-duration IM240 test scores.78Composite IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1981-1984 Model Year Light-Duty Gasoline Vehicles0.8 g/mi CutpointRegression CoefficientsModeRMSErrorConst C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23M1 0.301 0.566 5.043 . . ....... . .......... . .M2 0.253 0.378 0.187 2.802 . ....... . .......... . .M3 0.247 0.371 -0.383 2.022 2.586 ....... . .......... . .M4 0.232 0.337 -0.363 0.828 0.771 3.854...... . .......... . .M5 0.228 0.325 -0.454 1.046 -0.497 2.884 3.156..... . .......... . .M6 0.214 0.286 0.371 0.566 0.327 -0.040 1.592 4.850.... . .......... . .M7 0.202 0.274 0.697 0.468 0.136 -0.077 1.315 2.032 2.632 . . . ........... . .M8 0.194 0.260 0.489 0.715 -0.044 -0.411 1.211 2.268 0.853 2.410 . . ........... . .M9 0.189 0.247 0.452 0.747 0.049 -0.370 1.228 2.028 0.757 0.664 2.993 . ........... . .M10 0.185 0.242 0.163 0.947 -0.410 -0.223 0.801 1.855 0.909 0.463 2.017 2.189 ........... . .M11 0.182 0.236 -0.613 1.036 -0.076 -0.458 0.652 1.882 0.997 0.312 1.900 1.397 4.130.......... . .M12 0.160 0.179 0.127 0.496 0.458 -0.049 0.861 0.657 0.532 0.742 0.756 1.363 1.119 2.786......... . .M13 0.151 0.160 0.257 0.519 0.463 -0.050 0.494 0.783 0.574 0.498 0.793 1.013 1.266 2.081 2.388........ . .M14 0.149 0.156 0.285 0.535 0.377 0.080 0.324 0.741 0.578 0.480 0.878 0.729 1.310 2.069 1.748 1.228....... . .M15 0.146 0.152 0.397 0.612 0.326 -0.091 0.754 0.525 0.543 0.420 0.631 0.591 0.768 1.894 1.505 0.562 2.644...... . .M16 0.144 0.150 0.428 0.652 0.276 -0.140 0.404 0.656 0.668 0.406 0.658 0.454 -0.393 1.833 1.390 0.498 1.810 1.915..... . .M17 0.140 0.142 0.463 0.579 0.511 -0.148 0.619 0.189 0.756 0.455 0.462 0.632 -0.086 1.551 1.247 0.516 0.846 1.432 2.815.... . .M18 0.138 0.140 0.505 0.566 0.462 -0.015 0.443 0.386 0.676 0.317 0.386 0.622 -0.033 1.600 1.086 0.435 0.399 1.133 1.908 1.738 . . . . .M19 0.134 0.128 0.506 0.528 0.820 -0.205 0.294 0.539 0.735 0.259 0.147 1.098 -0.693 1.478 0.929 0.550 0.693 0.252 1.463 1.566 1.476 . . . .M20 0.102 0.058 0.441 0.520 0.567 0.283 0.334 0.275 0.678 0.396 0.600 1.082 0.232 0.525 0.815 0.244 0.831 1.083 0.721 1.244 0.809 0.931 . . .M21 0.068 0.032 0.507 0.551 0.501 0.508 0.307 0.466 0.393 0.487 0.542 1.195 0.446 0.329 0.563 0.546 0.500 0.690 0.700 0.763 0.805 0.426 1.089 . .M22 0.041 0.013 0.518 0.516 0.564 0.503 0.329 0.622 0.398 0.508 0.395 1.055 0.557 0.394 0.483 0.526 0.715 0.469 0.615 0.618 0.444 0.540 0.430 1.148 .M23 0.030 0.007 0.517 0.526 0.512 0.515 0.448 0.487 0.455 0.519 0.429 0.938 0.682 0.389 0.577 0.509 0.500 0.654 0.403 0.575 0.458 0.517 0.386 0.681 0.819NOTE: Results for only 23 modes are shown here because if the 24thmode is completed the actual IM240 score would then be used rather than the predicted score.79Phase 2 IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1981-1984 Model Year Light-Duty Gasoline Vehicles0.5 g/mi CutpointRegression CoefficientsModeNumberRMSErrorReg.Const.C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23P11 0.179 0.346 8.141 . ...........P12 0.145 0.219 2.349 3.104 ...........P13 0.136 0.198 1.727 2.209 2.823..........P14 0.134 0.192 1.330 2.210 2.034 1.470.........P15 0.131 0.188 0.571 1.862 1.732 0.807 2.665........P16 0.129 0.184 -0.983 1.887 1.610 0.588 1.883 2.208.......P17 0.125 0.171 -0.505 1.456 1.415 0.728 0.712 1.820 3.193......P18 0.122 0.168 -0.516 1.481 1.215 0.533 0.276 1.426 2.227 1.985.....P19 0.118 0.154 -0.904 1.381 1.041 0.803 0.703 0.602 1.573 1.758 1.711....P20 0.086 0.076 0.344 0.701 0.965 0.539 1.035 1.357 0.881 1.678 0.988 1.091 . . .P21 0.061 0.041 0.994 0.508 0.691 0.796 0.735 1.173 0.792 1.146 0.925 0.640 1.372 . .P22 0.039 0.016 1.142 0.562 0.700 0.745 1.010 0.779 0.752 0.874 0.560 0.732 0.647 1.544 .P23 0.029 0.007 1.198 0.561 0.777 0.755 0.770 1.005 0.484 0.833 0.607 0.715 0.560 0.975 1.098NOTE: Results for only modes are presented only for modes 11 through 23. Mode 11 is the first mode of Phase 2 and if the 24thmode is completed the actual IM240 full orcomposite score would be used rather than the predicted score.80Composite IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1985-1989 Model Year Light-Duty Gasoline Vehicles0.8 g/mi CutpointRegression CoefficientsModeRMSErrorConst C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23M1 0.301 0.4305.602 . . . . . . . . . .............M2 0.248 0.2590.159 3.044 . . . . . . . . .............M3 0.242 0.255-0.183 2.108 2.824 . . . . . . . .............M4 0.224 0.2230.012 1.015 0.555 3.864 . . . . . . .............M5 0.219 0.212-0.084 1.168 -0.763 2.919 3.395 . . . . . .............M6 0.207 0.1890.424 0.758 -0.026 0.591 1.742 4.092 . . . . .............M7 0.194 0.1810.649 0.668 -0.372 0.443 1.314 1.053 3.066 . . . .............M8 0.184 0.1690.369 0.880 -0.438 0.037 1.302 1.440 0.797 2.830 . . .............M9 0.174 0.1570.342 0.927 -0.266 -0.055 1.335 1.391 0.656 0.035 4.534 . .............M10 0.171 0.1540.180 1.101 -0.631 0.068 0.949 1.233 0.822 -0.082 3.332 2.217 .............M11 0.167 0.150-0.536 1.168 -0.318 -0.082 0.705 1.264 0.846 -0.127 3.103 1.373 4.334............M12 0.144 0.1060.170 0.593 0.221 0.266 0.883 0.515 0.448 0.428 1.462 1.314 1.001 2.829...........M13 0.137 0.0950.153 0.601 0.146 0.360 0.542 0.548 0.519 0.277 1.402 1.109 1.248 2.159 2.122 . . . . ......M14 0.135 0.0910.169 0.583 0.126 0.499 0.226 0.547 0.530 0.265 1.482 0.760 1.225 2.183 1.358 1.490 . . . ......M15 0.131 0.0890.272 0.609 0.139 0.358 0.572 0.388 0.544 0.195 1.174 0.605 0.985 1.914 1.217 0.696 2.684 . . ......M16 0.129 0.0870.278 0.683 0.092 0.322 0.166 0.487 0.671 0.212 1.115 0.457 -0.039 1.831 1.143 0.626 1.714 2.124 . ......M17 0.125 0.0810.348 0.641 0.274 0.241 0.418 0.209 0.775 0.207 0.887 0.657 0.145 1.602 0.944 0.500 0.969 1.584 2.648 ......M18 0.122 0.0800.348 0.651 0.147 0.387 0.291 0.439 0.622 0.115 0.812 0.631 0.217 1.651 0.809 0.246 0.548 1.358 1.605 1.837.....M19 0.116 0.0700.355 0.591 0.583 0.180 0.199 0.559 0.697 0.082 0.426 1.018 -0.368 1.511 0.738 0.346 0.826 0.523 1.293 1.374 1.818....M20 0.085 0.0290.432 0.465 0.545 0.443 0.311 0.226 0.677 0.359 0.604 1.148 0.387 0.555 0.731 0.187 1.034 0.908 0.755 1.211 0.916 0.953 . . .M21 0.055 0.0180.542 0.524 0.385 0.537 0.398 0.546 0.373 0.556 0.462 1.214 0.466 0.368 0.484 0.520 0.679 0.708 0.564 0.703 0.808 0.426 1.126 . .M22 0.035 0.0090.575 0.503 0.544 0.511 0.339 0.596 0.434 0.512 0.371 1.085 0.490 0.400 0.498 0.500 0.819 0.484 0.555 0.610 0.493 0.533 0.467 1.096 .M23 0.024 0.0040.574 0.499 0.516 0.525 0.455 0.493 0.482 0.528 0.353 0.981 0.668 0.420 0.558 0.534 0.542 0.577 0.422 0.576 0.522 0.504 0.427 0.599 0.842NOTE: Results for only 23 modes are shown here because if the 24thmode is completed the actual IM240 score would then be used rather than the predicted score.81Phase 2 IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1985-1989 Model Year Light-Duty Gasoline Vehicles0.5 g/mi CutpointRegression CoefficientsModeNumberRMSErrorReg.Const.C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23P11 0.177 0.259 9.328............P12 0.140 0.150 2.179 3.452...........P13 0.132 0.131 1.779 2.527 2.741..........P14 0.129 0.125 1.374 2.545 1.628 1.888.........P15 0.125 0.121 0.861 2.070 1.387 1.001 2.991........P16 0.123 0.119 -0.368 2.053 1.269 0.818 2.160 2.195.......P17 0.118 0.109 0.059 1.736 1.014 0.823 1.032 1.762 3.119......P18 0.115 0.107 -0.009 1.760 0.833 0.559 0.556 1.401 2.128 2.030.....P19 0.109 0.094 -0.526 1.622 0.698 0.823 0.762 0.636 1.569 1.573 2.175....P20 0.077 0.041 0.637 0.716 0.900 0.635 1.081 1.205 1.005 1.455 1.267 1.123 . . .P21 0.057 0.025 0.945 0.562 0.700 0.868 0.834 1.063 0.867 0.971 1.063 0.658 1.363 . .P22 0.037 0.013 0.917 0.590 0.738 0.748 1.105 0.785 0.740 0.839 0.583 0.740 0.631 1.554 .P23 0.027 0.006 1.052 0.609 0.774 0.810 0.757 0.906 0.536 0.802 0.675 0.711 0.575 0.903 1.137NOTE: Results for only modes are presented only for modes 11 through 23. Mode 11 is the first mode of Phase 2 and if the 24thmode is completed the actual IM240 full orcomposite score would be used rather than the predicted score.82Composite IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1990+ Model Year Light-Duty Gasoline Vehicles0.8 g/mi CutpointRegression CoefficientsModeRMSErrorConst. C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23M1 0.368 0.162 10.855 . . . . . . . ...............M2 0.271 0.028 0.252 4.621 . . . . . . ...............M3 0.253 0.036 0.096 2.693 4.788 . . . . . ...............M4 0.230 0.031 0.720 0.868 1.740 4.997 . . . . ...............M5 0.221 0.026 0.391 1.110 0.060 3.325 5.174 . . . ...............M6 0.207 0.021 0.862 0.623 1.005 0.397 2.743 5.132 . . ...............M7 0.192 0.025 1.279 0.372 0.699 0.393 2.028 1.127 3.732 . ...............M8 0.175 0.030 1.076 0.515 0.477 0.150 1.178 1.750 0.608 3.725 ...............M9 0.162 0.032 1.111 0.490 0.510 0.142 1.351 1.370 0.587 0.494 5.180..............M10 0.155 0.034 0.742 0.835 -0.133 0.470 0.754 0.829 0.980 0.287 3.033 3.511.............M11 0.149 0.037 -0.292 0.916 0.270 0.141 0.342 0.923 1.049 0.326 2.661 2.172 5.629............M12 0.123 0.028 0.433 0.321 0.650 0.528 0.818 -0.003 0.245 1.037 0.672 2.127 1.234 3.583...........M13 0.115 0.025 0.578 0.296 0.562 0.394 0.374 0.234 0.492 0.715 0.629 1.553 1.271 2.743 2.839..........M14 0.113 0.025 0.618 0.262 0.555 0.503 -0.034 0.227 0.569 0.714 0.776 1.121 1.069 2.758 1.607 2.069.........M15 0.107 0.027 0.747 0.284 0.574 0.244 0.529 0.033 0.676 0.571 0.487 1.011 0.912 2.369 1.258 0.591 3.362........M16 0.102 0.027 0.719 0.462 0.356 0.136 0.065 0.303 0.778 0.668 0.345 0.659 -0.008 2.189 1.033 0.401 2.153 2.766.......M17 0.098 0.026 0.794 0.426 0.518 0.062 0.242 0.168 0.786 0.737 0.079 0.882 0.127 1.928 0.726 0.488 1.245 1.994 2.960......M18 0.095 0.026 0.769 0.455 0.367 0.197 0.174 0.420 0.710 0.561 0.016 0.870 0.128 2.015 0.442 0.256 0.759 1.521 1.733 2.083.....M19 0.090 0.023 0.816 0.385 0.654 0.080 0.083 0.642 0.717 0.557 -0.358 1.269 -0.488 1.916 0.340 0.282 0.819 0.888 1.357 1.477 1.846 . . . .M20 0.068 0.009 0.575 0.360 0.539 0.382 0.257 0.458 0.639 0.556 0.034 1.205 0.514 0.804 0.472 0.255 0.693 1.266 0.881 1.203 0.837 1.073 . . .M21 0.041 0.007 0.544 0.483 0.489 0.528 0.539 0.520 0.388 0.588 0.284 1.157 0.523 0.367 0.461 0.575 0.548 0.853 0.677 0.674 0.583 0.370 1.309 . .M22 0.027 0.003 0.559 0.500 0.535 0.538 0.444 0.602 0.406 0.514 0.284 0.992 0.497 0.407 0.518 0.526 0.656 0.637 0.661 0.573 0.470 0.497 0.525 1.112 .M23 0.019 0.002 0.553 0.496 0.515 0.537 0.525 0.518 0.438 0.535 0.349 0.870 0.650 0.429 0.549 0.567 0.521 0.624 0.554 0.536 0.443 0.510 0.387 0.654 0.853NOTE: Results for only 23 modes are shown here because if the 24thmode is completed the actual IM240 score would then be used rather than the predicted score.83Phase 2 IM240 HC Regression Coefficients Developed from Modal IM240 Data Analysis1990+ Model Year Light-Duty Gasoline Vehicles0.5 g/mi CutpointRegression CoefficientsModeNumberRMSErrorReg.Const.C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23P11 0.153 0.098 13.195............P12 0.114 0.048 3.112 4.074...........P13 0.102 0.041 1.873 2.680 3.765..........P14 0.099 0.039 1.406 2.668 2.167 2.454.........P15 0.095 0.040 1.107 2.141 1.738 1.122 3.342........P16 0.091 0.040 -0.030 2.065 1.365 0.858 2.119 3.157.......P17 0.088 0.038 0.165 1.791 1.043 0.931 1.028 2.401 3.357......P18 0.085 0.038 0.093 1.843 0.719 0.663 0.610 1.854 2.189 2.206.....P19 0.081 0.035 -0.272 1.779 0.514 0.829 0.678 1.356 1.669 1.515 1.952....P20 0.057 0.016 0.581 0.846 0.727 0.616 0.627 1.840 1.313 1.345 0.856 1.195 . . .P21 0.040 0.010 0.817 0.585 0.723 0.936 0.588 1.434 1.014 0.886 0.731 0.623 1.512 . .P22 0.028 0.005 0.823 0.606 0.751 0.837 0.740 1.015 0.843 0.855 0.581 0.717 0.749 1.426 .P23 0.020 0.003 0.909 0.612 0.790 0.837 0.609 0.957 0.714 0.775 0.632 0.719 0.591 0.868 1.158NOTE: Results for only modes are presented only for modes 11 through 23. Mode 11 is the first mode of Phase 2 and if the 24thmode is completed the actual IM240 full orcomposite score would be used rather than the predicted score.84 Appendix E
Calculation of Raw Emission Scores from Dilute Measurements85 Calculation of Raw Emission Scores from Dilute Measurements
The constant volume sampling technique, which has been part of the FTP for the exhaust emissions testing of passenger cars and light-duty trucks since the 1972 model year, involves the collection of a sample of exhaust gas after it has been diluted to a known, constant volume. Using this procedure, a device called a "constant volume sampler" dilutes the vehicle exhaust and then samples a constant volume fraction of the dilute mixture. In a typical test facility, the dilution is achieved by drawing "background" air from the room where the vehicle is being driven on a chassis dynamometer. A slipstream from the diluted exhaust is pumped into a series of sample bags during the test. Three sample bags are used for dilute exhaust samples: the first represents the "cold start" phase of the test, the second represents "stabilized" operation, and the third represents the "hot start" phase of the test. Samples of background air are simultaneously collected in three additional bags. At the end of the test, measurement of the concentration of pollutants in the sample bags and calculation of the total flow of the dilute mixture during each phase allows the mass of emissions emitted during each phase of the test to be calculated. Division of the calculated mass by the associated driving distance provides the mass emissions rate (normally expressed in grams per mile).

A variation of the FTP test procedure is used in CVS-based I/M testing. Instead of filling sample bags with dilute mixture during separate phases of the test, the concentrations of pollutants in the dilute exhaust stream are continuously monitored. Mass emissions per mile of travel are calculated from integration of the continuous measurements divided by the distance driven during the test. (This technique facilitates the use of "fast pass" and "fast fail" algorithms for shortening the test in cases where a vehicle is extremely clean or extremely dirty during the early portion of the test.)

In CVS-based testing, the volume of background (dilution) air in the sample substantially exceeds the volume of exhaust gas, usually by a factor of ten or more. As a result, the extent to which the dilution air is contaminated with pollutants can significantly affect the calculated mass emissions. To eliminate this interference, the extent to which the vehicle exhaust has been diluted must be known. The FTP specifies that the ratio of total volume to exhaust volume ("dilution factor") be calculated using the following equation:

[1] 

## D F 13.4 CO CO HC EPA 2e e e 

## = + +

where: CO 2e , CO e , and HC e are the concentrations measured in the dilute sample expressed as percent volume.

In the above equation, the DF calculated in accordance with the FTP is specified as "DF EPA " to distinguish it from an improved formulation of the DF discussed below. As noted above, DF EPA is used in the FTP to correct the emissions concentration in the sample bag for pollutants in the dilution (background) air. Although not required by the FTP, the average DF can also be used to calculate the average concentration of the undiluted tailpipe emissions emitted while the sample bag was being filled. If there were no pollutants in the dilution air, the tailpipe concentrations could be calculated simply by multiplying the dilute measurement by the DF:86 [2] Ctp = Cconc * DF

where: Ctp is the actual raw tailpipe concentration, and Cconc is the concentration of a pollutant in the dilute sample defined as:
[3] C conc = C e - C d (1 - ) 

### 1 D F
where Ce is the pollutant dilute concentration and Cd is the pollutant background concentration.

Substituting [3] into [2] yields:

[4] 

## Ctp Ce Cd 1 1 D F D F =− −     

      

As noted above, the CVS technique used to measure emissions in I/M programs involves calculating mass emissions by integrating the continuously monitored dilute sample. An average dilution factor can still be calculated from the integrated average of the dilute emissions. The DF can also be calculated continuously and used to calculate the undiluted tailpipe concentration at any point in time. This capability makes it possible to use the CVS emissions measurement system to determine whether a vehicle meets emissions standards that are based on tailpipe concentrations. If, for example, a CO concentration of 0.1% is measured in the dilute exhaust stream, and if the calculated DF is 10, then the tailpipe emission concentration would be calculated to be 1.0% CO (assuming background concentrations were zero).

Although there are several advantages associated with the use of the reverse dilution calculation method, some error is introduced in the calculation of the tailpipe concentration due to the discrepancies that can exist between actual test conditions and the assumptions on which the standard DF calculation is based. As described in detail in a previously referenced technical paper (SAE paper 980678), the DF equation contained in the FTP is based on three assumptions:

1. Exhaust emissions of vehicles are the product of a chemically balanced (i.e., stoichiometric) ratio of air and fuel; 2.The concentrations of pollutants in the background air have an insignificant effect on the calculation of the DF; and 3. No water vapor has been removed from the sample.

Each of these assumptions is problematic when the reverse dilution technique is used to calculate the concentration of pollutants in a vehicle tailpipe that would otherwise be measured directly in an I/M program. First, although most vehicles run very close to a stoichiometric air-fuel ratio, this is not always the case. Second, in the3 So-called "BAR90" analyzers actually use a condensate removal system to dispose of the water that condenses when raw exhaust is drawn through the sample probe; however, the efficiency of water removal depends on the temperature of the exhaust sample because no temperature control is provided by the analyzer.

4 The DF equation in the previously referenced SAE paper is based on the simplifying assumption that there is no residual oxygen in the exhaust of stoichiometric or richer air-fuel mixtures. This assumption holds unless there is substantial misfire. In the case of misfire, the exhaust may contain oxygen that dilutes the concentration of other constituents. Equation 4 is a refinement of the equation contained in the SAE paper that accounts for misfire.

5 Air injection can reduce mass emissions by facilitating more complete combustion in either the exhaust manifold or the catalytic converter. However, the dilution associated with air injection causes the measured concentration to be

87 environment of an I/M test lane, pollution in the background air can be significant. Third, analyzers routinely used for raw exhaust measurement remove a substantial amount of water from the sample. 3

A more complicated expression of the DF is required to address the limitations of the DF equation contained in the FTP. The recommended equation is as follows: 4 

# ( )() ( ) 

# ( ) D F 100 K CO K CO K (HC ) K CO CO K CO CO K (HC HC ) 1 2 d 2 d 3 d

1 2e 2d 2 e d 3 e d 

### = − −− − + −+ −

where: K 1 , K 2 , and K 3 are constants that depend on the fuel type (see below); CO 2d is the concentration of CO 2 in the background air; CO d is the concentration of CO in the background air; HC d is the concentration of HC in the background air; CO 2e is the concentration of CO 2 in the dilute sample; CO e is the concentration of CO in the dilute sample; and HC e is the concentration of HC in the dilute sample.

All of the concentrations in the above equation are expressed in volume percent. The HC values are expressed in hexane equivalent. The values of K 1 , K 2 , and K 3 depend on the type of fuel and whether the calculated pollutant concentrations are on a wet or dry basis. When attempting to match measurements that would be made by typical systems for raw exhaust measurement, the values for dry exhaust should be used. For gasoline fuel with pollutant concentrations measured on a wet basis, such as in IM240 set-ups, the value of K 1 is 6.5431, the value for K 2 is 4.6561, and the value of K 3 is 57.0945.

Dilution Correction of Tailpipe Measurements As noted earlier, one of the problems associated with I/M standards based on maximum allowable tailpipe concentrations is that certain causes of dilution (e.g., air injection, 5 exhaust leaks, or inadequate sample probe insertionreduced by more than the true reduction in mass emissions.

6 With measurement systems that remove water, and for an engine running a stoichiometric, a 6% sum of CO and CO 2 represents each part exhaust being diluted with 1.5 parts air.

88 depth) may cause measured concentrations to be substantially lower than for another vehicle with identical mass emissions. Because of this problem, EPA guidance for concentration measurement during simple I/M tests specifies that the sum of CO plus CO 2 emissions should be at least 6% in order for the test to be considered valid. Although the basis for the recommendation is not documented, it appears to represent the maximum level of exhaust dilution that might be expected with a relatively high output air injection system installed on a relatively small engine. As a result, it allows the exhaust concentration to be reduced by more than 50% due to various sources of dilution. 6 It is therefore a relatively ineffective means of preventing exhaust dilution from affecting the results of an I/M test.

Recently, the California Bureau of Automotive Repair (BAR) devised an improved procedure for eliminating the effects of exhaust dilution. BAR’s procedure uses equations developed from basic combustion chemistry to determine the extent to which an exhaust sample must have been diluted before a concentration measurement was made. The measured concentrations are adjusted to what they would be under stoichiometric conditions with no dilution air from any source (including leaner than stoichiometric operation). BAR’s exhaust dilution correction essentially involves the application of a dilution factor to the concentrations measured at the tailpipe. As described in Sierra’s SAE paper, BAR’s method is more sophisticated than the DF calculation incorporated into the FTP because it accounts for variations in air-fuel ratio. However, the BAR procedure ignores the effects of background air, which is not a factor during tailpipe measurements. As the SAE paper illustrates, Sierra’s recommended DF equation incorporates the same basic dilution correction used by BAR in combination with a correction for pollutants in the background air. When correcting tailpipe concentrations for dilution, where no background air is involved, Sierra’s DF calculation and BAR’s dilution adjustment produce the same result.

Recognizing the advantages of BAR’s new dilution correction procedure, EPA has incorporated it in Guidance to states on Acceleration Simulation Mode (ASM) testing. Although BAR’s procedure is equally applicable to other tests that rely on concentration measurement, it has not yet been incorporated into revised guidance for idle, 2500 rpm, and other steady-state tests. However, when CVS testing is used in combination with Sierra’s recommended reverse dilution calculation procedure, the effect is similar to using BAR’s dilution correction.89 Appendix F Modal Analysis of Second-by-Second Data Preconditioning Guidelines

Developed by Sierra Research Contract 68-C4-0056 Work Assignment 2-0490 Modal Analysis of Second-by-Second Data Preconditioning Guidelines
Developed by Sierra Research Contract 68-C4-0056 Work Assignment 2-04

Using the replicate IM240 data collected by Gordon-Darby, it was possible, through trial and error, to identify crite ria to determine whether a vehicle failing an initial IM240 is inadequately preconditioned and should be tested again. This analysis was performed for each pollutant individually, and then for all pollutants combined. The analysis included 283 LDVs and 83 LDTs. The evaluation followed a step-wise progression in which the aim was to maximize the identification of vehicles that could benefit from a second test, while minimizing testing of vehicles likely to fail a second test. Recommendations for passenger cars are summarized below. A similar set of conditions was also developed for light-duty trucks, which are subject to different IM240 standards than passenger cars.

IM240 Retest Criteria for Passenger Cars

HC Failures - If PPmHC209-214 is less than 1,500, a retest is recommended if any of the following occur:
1. Phase 2 HC < 0. 8 g/mi; or 2. massHC 175-199 < 0.2 g; or 3. (ppmHC 75-80 /ppmHC 214 ) > 4.0
For vehicles failing only HC, the following additional constraints are required for a vehicle to be retested:

1. Mass HC 175-199 <0.3g and (ppmHC 75-80 /ppmHC 209-214 )>1.5;or 2. Mass HC 175-199 < 0.3g and Phase 2 HC < 1.0 g/mi

CO Failures - For CO failures, the above criteria for HC are recommended. In addition, the following constraints are recommended:
1. do not retest if Phase 2 CO > 20 g/mi and (Phase 1 CO/Phase 2 CO) <2; and 2. if the vehicle fails both HC and CO, retest if Mass HC 175-199 <0.3 g and mass CO 175-199 < 5.0 g.
If the vehicle is a CO-only failure, then a vehicle would benefit from a retest if:

1. Mass CO 175-199 < 6.0 g; or 2. (ppmCO 75-80 /ppmCO 209-214 ) > 4.0; or 3. Mass CO 175.199 < 10 g and (Phase I CO > 0.75 x Phase 2 CO).

NOx Failures - For vehicles failing HC or CO and NOx, a retest is recommended if the following condition occurs: 1. Mass NOx 175-199 = 1.0g91 For NOx Only failures, retest is recommended if the following criteria are met:

1. Mass NOx 175199 <9; or 2. Mass NOx 175-199 <1.l and(ppmNOx 40-45 /ppmNOx 209-215 )>1.5;or 3. IM240 NOx<2.2 and (ppmNOx 40-45 / ppmNOx 209-215 )> 1.0
Multiple Pollutants - For multiple pollutant failures, a retest is eliminated under the following conditions:
1. the vehicle fails for all pollutants; or 2. the vehicle fails HC and CO and (Phase 2 CO > 20 g/mi and mass CO 175-199 >6.0 g); or 3. the vehicle fails HC and NOx and (ppmHC 209-214 >1,200) or (ppmNOx 209-214 > 1,200

IM240 Retest Criteria for Light-Duty Trucks
Because they are subject to different numerical IM240 emission standards, a different set of retest criteria were developed for light-duty trucks. These criteria are similar to those established for passenger cars, with adjustments to account for standards differences.

HC Failures - For 1981 to 1983 model year vehicles, if ppmHC 209-214 < 2,000 and any of the following conditions exist, then a retest is recommended:
1. Phase 2 HC < 3.0 g/mi; or 2. Mass HC 175-199 < 0.8 g; or 3. (ppmHC 75-80 /ppmHC 209-214 )>4.0
In addition, if the full IM240 is less than 3.5 g/mi HC (regardless of the value of ppmHC 209-214 ), then a retest is recommended.

For 1984 and later model year vehicles, if ppmHC 209-214 <1,500 and any of the following conditions exist a retest is recommended:
1. Phase 2 HC< 2.0 g/mi; or 2. MassHC 175-199 < 0.4 g; or 3. (ppmHC 75-80 /ppmHC 209-214 )>4.0

In addition, if 0.4<Mass HC 175-199 <0.8 and (ppmHC 75-80 /ppmHC 209-214 )>2.0 (regardless of the value of ppmHC 209-214 ) then a retest is recommended.

A retest is not recommended if Phase 2 HC > 3.2 g/mi.

CO Failures - For CO failures, the above criteria outlined for HC were also used. In addition, the following conditions were also imposed to cut down on the number of vehicles incorrectly identified as needing a retest:92 1. If 1981 to 1983 model year and Mass CO 175-199 >36g then do not retest. 2. If 1984 or later model year and Mass CO 175-199 >18g then do not retest. 3. If Phase 2 CO>40 and Phase 2 CO > Phase I CO then do not retest.

NOx Failures - If the vehicle failed NOx and either HC or CO, the above criteria were used to determine the need for a retest. For LDT1&2s, if the vehicle failed only NOx . then a retest is recommended if Mass NOx l75-199 < 1.4 g. For 1988 and later LDT3&4s, a retest is recommended only if Mass NOx 175-199 < 2.5 g.93 Appendix G Full and Fast-Pass IM240 Positive Kinetic Energy Speed Variation Limits
Developed by Sierra Research Contract 68-C4-00567 W. J. Webster and C. Shih, "A Statistically Derived Metric to Monitor Time-Speed Variability in Practical Emissions Testing," New York State Department of Environmental Conservation, presented at the 6th CRC On-Road Vehicle Emissions Workshop, March 18-20, 1996.
94 

### D P V 2 V V 

## P P

t t t1 t 2 t -1 2 t-2 2 

### =− = − +

− 

# S p ecific Power p ower
mass work m ass tim e kinetic ener g y m ass tim e mass V m ass tim e 1 2 

# = = × = × = × ×
× ∆ ∆ ∆ ∆ ∆ 2

Pt Vt 2 Vt 1 2
= −− Full and Fast-Pass IM240 Positive Kinetic Energy Speed Variation Limits
Developed by Sierra Research Contract 68-C4-0056

Evaluation of Alternative Statistical Measures
Based upon similar work conducted by the New York Automotive Emissions Laboratory (AEL,) 7 two easily determined, alternative statistical metrics were evaluated for their ability to identify and quantify IM240 speed variations th at significantly affect emissions:
(1). DPWRSUM - the sum of absolute changes in specific power; and
(2). Positive Kinetic Energy (PKE) - the sum of positive differences in kinetic energy per unit distance.
Each of these metrics are explained in more detail below.
DPWRSUM - Specific power is defined as power per unit mass, which can be restated as follows:

Over a transient driving cycle of second-by-second speeds, EPA defines the specific power P at any time t (and dropping the factor of 1⁄2) as:

The absolute difference in specific power at time t can then be written as:

The DPWRSUM statistic then is defined over a cycle of N seconds as:95 

# DPWRSUM DP V 2 V V t t 0 N

t 2 t -1 2 t-2 2

t 0 N 

## = = −+

= = 

# ∑ ∑

PKE P P

d x t t 0 N

0 x 

### = = 

# ∑

∫

PP V V t t 2 t -1 2 

## = − PKE - Positive Kinetic Energy has been defined mathematically as:

over a traveled driving cycle of distance x where PP is the positive specific power and is given by the following expression when V t > V t-1 , and is zero when V t  V t-1 .

Each of these metrics can be easily computed from the second-by-second speed measurements collected in IM240 testing. In comparing their relative ability to identify speed variations that produce high emissions, it is helpful to consid er which speed variations contribute to the value of each metric (similar to the earlier examination of the SE statistic) over an IM240 test.
Note that although both DPWRSUM and PKE are affected by differences in specific power or squared speeds over "adjacent" seconds of an IM240 trace, the value of DPWRSUM is increased during decelerations as well as accelerations. PKE on the other hand, is only increased during acceleration periods.96 

### IM240 REFERENCE DATA PKE VARIATION CUTPOINTS (miles/hr2)
CUM PKE "BASE

" MULT. VARYING CUMULATIVE PKE TIME SPEED (miles/hr2 ) DELTA FACTO R DELTA LOW HIGH

0 0.0 0.0 . . . . . 1 0.0 0.0 . . . . . 2 0.0 0.0 . . . . . 3 0.0 0.0 . . . . . 4 0.0 0.0 . . . . . 5 3.0 10,800.0 . . . . . 6 5.9 14,080.4 . . . . . 7 8.6 15,214.6 . . . . . 8 11.5 16,417.2 . . . . . 9 14.3 17,001.5 . . . . . 10 16.9 17,079.7 . . . . . 11 17.3 13,902.5 . . . . . 12 18.1 12,336.8 . . . . . 13 20.7 13,263.7 . . . . . 14 21.7 12,284.1 . . . . . 15 22.4 11,261.4 . . . . . 16 22.5 9,964.5 . . . . . 17 22.1 8,890.2 . . . . . 18 21.5 8,046.4 . . . . . 19 20.9 7,366.6 . . . . . 20 20.4 6,805.5 . . . . . 21 19.8 6,336.9 . . . . . 22 17.0 5,983.3 . . . . . 23 14.9 5,704.2 . . . . . 24 14.9 5,450.1 . . . . . 25 15.2 5,306.1 . . . . . 26 15.5 5,171.6 . . . . . 27 16.0 5,103.3 . . . . . 28 17.1 5,213.3 . . . . . 29 19.1 5,599.3 . . . . . 30 21.1 5,990.0 342.3 4.000 1,369.3 4,621 7,359 31 22.7 6,242.3 356.7 3.986 1,421.8 4,820 7,664 32 22.9 6,014.8 343.7 3.971 1,365.1 4,650 7,380 33 22.7 5,745.3 328.3 3.957 1,299.3 4,446 7,045 34 22.6 5,500.0 314.3 3.943 1,239.3 4,261 6,739 35 21.3 5,287.2 302.2 3.929 1,187.0 4,100 6,474 36 19.0 5,110.8 292.1 3.914 1,143.3 3,968 6,254 37 17.1 4,961.9 283.6 3.900 1,105.9 3,856 6,06897 38 15.8 4,831.8 276.1 3.886 1,072.9 3,759 5,905 39 15.8 4,708.3 269.1 3.871 1,041.7 3,667 5,750 40 17.7 4,937.5 282.2 3.857 1,088.4 3,849 6,026 41 19.8 5,220.8 298.4 3.843 1,146.5 4,074 6,367 42 21.6 5,450.3 311.5 3.829 1,192.5 4,258 6,643 43 23.2 5,638.2 322.2 3.814 1,229.0 4,409 6,867 44 24.2 5,685.3 324.9 3.800 1,234.6 4,451 6,920 45 24.6 5,592.5 319.6 3.786 1,209.9 4,383 6,802 46 24.9 5,481.7 313.3 3.771 1,181.5 4,300 6,663 47 25.0 5,332.7 304.8 3.757 1,145.0 4,188 6,478 48 25.7 5,321.5 304.1 3.743 1,138.2 4,183 6,460 49 26.1 5,245.9 299.8 3.729 1,117.8 4,128 6,364 50 26.7 5,216.3 298.1 3.714 1,107.2 4,109 6,323 51 27.5 5,230.2 298.9 3.700 1,105.9 4,124 6,336 52 28.6 5,307.9 303.3 3.686 1,118.0 4,190 6,426 53 29.3 5,298.0 302.8 3.671 1,111.6 4,186 6,410 54 29.8 5,246.1 299.8 3.657 1,096.4 4,150 6,343 55 30.1 5,155.0 294.6 3.643 1,073.2 4,082 6,228 56 30.4 5,068.3 289.6 3.629 1,051.0 4,017 6,119 57 30.7 4,985.6 284.9 3.614 1,029.8 3,956 6,015 58 30.7 4,848.3 277.1 3.600 997.5 3,851 5,846 59 30.5 4,719.2 269.7 3.586 967.0 3,752 5,686 60 30.4 4,597.2 262.7 3.571 938.3 3,659 5,535 61 30.3 4,481.7 256.1 3.557 911.1 3,571 5,393 62 30.4 4,389.2 250.8 3.543 888.7 3,501 5,278 63 30.8 4,352.1 248.7 3.529 877.6 3,474 5,230 64 30.4 4,250.1 242.9 3.514 853.6 3,397 5,104 65 29.9 4,154.4 237.4 3.500 831.0 3,323 4,985 66 29.5 4,064.1 232.3 3.486 809.6 3,255 4,874 67 29.8 4,022.9 229.9 3.471 798.1 3,225 4,821 68 30.3 4,013.3 229.3 3.457 792.9 3,220 4,806 69 30.7 3,988.8 228.0 3.443 784.8 3,204 4,774 70 30.9 3,935.5 224.9 3.429 771.1 3,164 4,707 71 31.0 3,869.4 221.1 3.414 755.0 3,114 4,624 72 30.9 3,791.8 216.7 3.400 736.8 3,055 4,529 73 30.4 3,718.5 212.5 3.386 719.5 2,999 4,438 74 29.8 3,649.2 208.5 3.371 703.1 2,946 4,352 75 29.9 3,595.5 205.5 3.357 689.8 2,906 4,285 76 30.2 3,569.2 204.0 3.343 681.9 2,887 4,251 77 30.7 3,569.2 204.0 3.329 678.9 2,890 4,248 78 31.2 3,569.3 204.0 3.314 676.0 2,893 4,245 79 31.8 3,582.2 204.7 3.300 675.6 2,907 4,258 80 32.2 3,569.2 204.0 3.286 670.2 2,899 4,23998 81 32.4 3,531.2 201.8 3.271 660.2 2,871 4,191 82 32.2 3,469.8 198.3 3.257 645.9 2,824 4,116 83 31.7 3,411.4 195.0 3.243 632.2 2,779 4,044 84 28.6 3,360.3 192.0 3.229 620.0 2,740 3,980 85 25.1 3,316.8 189.5 3.214 609.3 2,708 3,926 86 21.6 3,280.2 187.5 3.200 599.9 2,680 3,880 87 18.1 3,250.2 185.7 3.186 591.7 2,658 3,842 88 14.6 3,226.3 184.4 3.171 584.7 2,642 3,811 89 11.1 3,208.4 183.4 3.157 578.9 2,630 3,787 90 7.6 3,196.3 182.7 3.143 574.1 2,622 3,770 91 4.1 3,189.8 182.3 3.129 570.3 2,619 3,760 92 0.6 3,188.9 182.2 3.114 567.5 2,621 3,756 93 0.0 3,188.9 182.2 3.100 564.9 2,624 3,754 94 0.0 3,188.9 182.2 3.086 562.3 2,627 3,751 95 0.0 3,188.9 182.2 3.071 559.7 2,629 3,749 96 0.0 3,188.9 182.2 3.057 557.1 2,632 3,746 97 0.0 3,188.9 182.2 3.043 554.5 2,634 3,743 98 3.3 3,203.1 183.0 3.029 554.4 2,649 3,757 99 6.6 3,250.7 185.8 3.014 560.0 2,691 3,811 100 9.9 3,331.3 190.4 3.000 571.1 2,760 3,902 101 13.2 3,443.8 196.8 2.986 587.6 2,856 4,031 102 16.5 3,587.2 205.0 2.971 609.1 2,978 4,196 103 19.8 3,760.1 214.9 2.957 635.4 3,125 4,396 104 22.2 3,892.7 222.5 2.943 654.7 3,238 4,547 105 24.3 4,013.3 229.4 2.929 671.7 3,342 4,685 106 25.8 4,090.8 233.8 2.914 681.3 3,409 4,772 107 26.4 4,093.0 233.9 2.900 678.3 3,415 4,771 108 25.7 4,045.3 231.2 2.886 667.1 3,378 4,712 109 25.1 3,999.9 228.6 2.871 656.4 3,344 4,656 110 24.7 3,956.1 226.1 2.857 646.0 3,310 4,602 111 25.2 3,951.8 225.8 2.843 642.0 3,310 4,594 112 25.4 3,924.1 224.3 2.829 634.3 3,290 4,558 113 27.2 4,024.3 230.0 2.814 647.2 3,377 4,672 114 26.5 3,979.2 227.4 2.800 636.7 3,342 4,616 115 24.0 3,939.2 225.1 2.786 627.1 3,312 4,566 116 22.7 3,902.0 223.0 2.771 618.0 3,284 4,520 117 19.4 3,870.9 221.2 2.757 609.9 3,261 4,481 118 17.7 3,842.9 219.6 2.743 602.4 3,241 4,445 119 17.2 3,816.0 218.1 2.729 595.0 3,221 4,411 120 18.1 3,834.3 219.1 2.714 594.8 3,240 4,429 121 18.6 3,832.2 219.0 2.700 591.3 3,241 4,423 122 20.0 3,879.0 221.7 2.686 595.4 3,284 4,474 123 20.7 3,887.7 222.2 2.671 593.5 3,294 4,48199 124 21.7 3,914.4 223.7 2.657 594.4 3,320 4,509 125 22.4 3,923.5 224.2 2.643 592.6 3,331 4,516 126 22.5 3,895.8 222.6 2.629 585.2 3,311 4,481 127 22.1 3,863.1 220.8 2.614 577.1 3,286 4,440 128 21.5 3,831.7 219.0 2.600 569.3 3,262 4,401 129 20.9 3,801.8 217.3 2.586 561.8 3,240 4,364 130 20.4 3,772.9 215.6 2.571 554.4 3,219 4,327 131 19.8 3,745.4 214.0 2.557 547.3 3,198 4,293 132 17.0 3,722.1 212.7 2.543 540.9 3,181 4,263 133 17.1 3,703.4 211.6 2.529 535.1 3,168 4,239 134 15.8 3,682.2 210.4 2.514 529.1 3,153 4,211 135 15.8 3,661.2 209.2 2.500 523.1 3,138 4,184 136 17.7 3,720.0 212.6 2.486 528.4 3,192 4,248 137 19.8 3,794.6 216.9 2.471 535.9 3,259 4,330 138 21.6 3,860.2 220.6 2.457 542.1 3,318 4,402 139 22.2 3,863.3 220.8 2.443 539.3 3,324 4,403 140 24.5 3,964.6 226.6 2.429 550.2 3,414 4,515 141 24.7 3,943.1 225.3 2.414 544.0 3,399 4,487 142 24.8 3,915.9 223.8 2.400 537.1 3,379 4,453 143 24.7 3,883.2 221.9 2.386 529.4 3,354 4,413 144 24.6 3,851.1 220.1 2.371 521.9 3,329 4,373 145 24.6 3,819.6 218.3 2.357 514.5 3,305 4,334 146 25.1 3,817.5 218.2 2.343 511.1 3,306 4,329 147 25.6 3,815.4 218.0 2.329 507.7 3,308 4,323 148 25.7 3,789.6 216.6 2.314 501.2 3,288 4,291 149 25.4 3,758.6 214.8 2.300 494.0 3,265 4,253 150 24.9 3,728.8 213.1 2.286 487.1 3,242 4,216 151 25.0 3,704.9 211.7 2.271 480.9 3,224 4,186 152 25.4 3,698.2 211.3 2.257 477.0 3,221 4,175 153 26.0 3,702.8 211.6 2.243 474.6 3,228 4,177 154 26.0 3,673.1 209.9 2.229 467.8 3,205 4,141 155 25.7 3,644.1 208.3 2.214 461.1 3,183 4,105 156 26.1 3,637.9 207.9 2.200 457.4 3,181 4,095 157 26.7 3,643.0 208.2 2.186 455.0 3,188 4,098 158 27.3 3,648.1 208.5 2.171 452.7 3,195 4,101 159 30.5 3,812.6 217.9 2.157 470.0 3,343 4,283 160 33.5 3,978.0 227.3 2.143 487.1 3,491 4,465 161 36.2 4,133.0 236.2 2.129 502.8 3,630 4,636 162 37.3 4,172.3 238.4 2.114 504.1 3,668 4,676 163 39.3 4,282.5 244.7 2.100 513.9 3,769 4,796 164 40.5 4,330.6 247.5 2.086 516.2 3,814 4,847 165 42.1 4,412.1 252.1 2.071 522.3 3,890 4,934 166 43.5 4,477.8 255.9 2.057 526.4 3,951 5,004100 167 45.1 4,561.4 260.7 2.043 532.5 4,029 5,094 168 46.0 4,584.2 262.0 2.029 531.4 4,053 5,116 169 46.8 4,598.2 262.8 2.014 529.3 4,069 5,127 170 47.5 4,603.2 263.1 2.000 526.1 4,077 5,129 171 47.5 4,546.8 259.8 1.986 516.0 4,031 5,063 172 47.3 4,492.0 256.7 1.971 506.1 3,986 4,998 173 47.2 4,438.6 253.7 1.957 496.4 3,942 4,935 174 47.2 4,386.5 250.7 1.943 487.0 3,899 4,874 175 47.4 4,352.1 248.7 1.929 479.7 3,872 4,832 176 47.9 4,343.2 248.2 1.914 475.1 3,868 4,818 177 48.5 4,342.6 248.2 1.900 471.5 3,871 4,814 178 49.1 4,342.0 248.1 1.886 467.9 3,874 4,810 179 49.5 4,324.9 247.2 1.871 462.5 3,862 4,787 180 50.0 4,316.3 246.7 1.857 458.1 3,858 4,774 181 50.6 4,316.0 246.7 1.843 454.5 3,861 4,771 182 51.0 4,299.3 245.7 1.829 449.3 3,850 4,749 183 51.5 4,291.0 245.2 1.814 444.9 3,846 4,736 184 52.2 4,299.3 245.7 1.800 442.3 3,857 4,742 185 53.2 4,332.3 247.6 1.786 442.1 3,890 4,774 186 54.1 4,356.8 249.0 1.771 441.0 3,916 4,798 187 54.6 4,347.7 248.5 1.757 436.6 3,911 4,784 188 54.9 4,322.3 247.0 1.743 430.5 3,892 4,753 189 55.0 4,280.9 244.6 1.729 422.9 3,858 4,704 190 54.9 4,232.4 241.9 1.714 414.6 3,818 4,647 191 54.6 4,185.2 239.2 1.700 406.6 3,779 4,592 192 54.6 4,139.1 236.5 1.686 398.7 3,740 4,538 193 54.8 4,109.5 234.9 1.671 392.5 3,717 4,502 194 55.1 4,088.2 233.6 1.657 387.2 3,701 4,475 195 55.5 4,075.0 232.9 1.643 382.6 3,692 4,458 196 55.7 4,046.6 231.3 1.629 376.6 3,670 4,423 197 56.1 4,034.0 230.5 1.614 372.1 3,662 4,406 198 56.3 4,006.4 229.0 1.600 366.3 3,640 4,373 199 56.6 3,986.7 227.8 1.586 361.3 3,625 4,348 200 56.7 3,952.4 225.9 1.571 354.9 3,597 4,307 201 56.7 3,911.4 223.5 1.557 348.1 3,563 4,259 202 56.3 3,871.4 221.2 1.543 341.3 3,530 4,213 203 56.0 3,832.5 219.0 1.529 334.8 3,498 4,167 204 55.0 3,795.0 216.9 1.514 328.4 3,467 4,123 205 53.4 3,759.3 214.8 1.500 322.3 3,437 4,082 206 51.6 3,725.4 212.9 1.486 316.3 3,409 4,042 207 51.8 3,704.9 211.7 1.471 311.5 3,393 4,016 208 52.1 3,691.1 210.9 1.457 307.4 3,384 3,998 209 52.5 3,683.7 210.5 1.443 303.7 3,380 3,987101 210 53.0 3,682.8 210.5 1.429 300.7 3,382 3,984 211 53.5 3,682.0 210.4 1.414 297.6 3,384 3,980 212 54.0 3,681.1 210.4 1.400 294.5 3,387 3,976 213 54.9 3,705.8 211.8 1.386 293.5 3,412 3,999 214 55.4 3,704.7 211.7 1.371 290.4 3,414 3,995 215 55.6 3,684.4 210.6 1.357 285.8 3,399 3,970 216 56.0 3,677.1 210.1 1.343 282.2 3,395 3,959 217 56.0 3,644.6 208.3 1.329 276.7 3,368 3,921 218 55.8 3,612.7 206.5 1.314 271.3 3,341 3,884 219 55.2 3,581.7 204.7 1.300 266.1 3,316 3,848 220 54.5 3,551.6 203.0 1.286 261.0 3,291 3,813 221 53.6 3,522.5 201.3 1.271 255.9 3,267 3,778 222 52.5 3,494.5 199.7 1.257 251.1 3,243 3,746 223 51.5 3,467.4 198.2 1.243 246.3 3,221 3,714 224 50.5 3,441.2 196.7 1.229 241.6 3,200 3,683 225 48.0 3,416.8 195.3 1.214 237.1 3,180 3,654 226 44.5 3,394.4 194.0 1.200 232.8 3,162 3,627 227 41.0 3,374.0 192.8 1.186 228.6 3,145 3,603 228 37.5 3,355.6 191.8 1.171 224.6 3,131 3,580 229 34.0 3,339.0 190.8 1.157 220.8 3,118 3,560 230 30.5 3,324.3 190.0 1.143 217.1 3,107 3,541 231 27.0 3,311.4 189.2 1.129 213.6 3,098 3,525 232 23.5 3,300.3 188.6 1.114 210.2 3,090 3,510 233 20.0 3,290.9 188.1 1.100 206.9 3,084 3,498 234 16.5 3,283.1 187.6 1.086 203.7 3,079 3,487 235 13.0 3,277.1 187.3 1.071 200.7 3,076 3,478 236 9.5 3,272.7 187.0 1.057 197.7 3,075 3,470 237 6.0 3,269.9 186.9 1.043 194.9 3,075 3,465 238 2.5 3,268.7 186.8 1.029 192.1 3,077 3,461 239 0.0 3,268.7 186.8 1.014 189.5 3,079 3,458 Cycle Sums 3,268.7 3,079 3,458102 Appendix H
Derivation of TRLHP Coefficients103 Derivation of TRLHP Coefficients

(a) Road Load Equation
(1) Vehicle Loading . Road load is defined by the following equation relating track road load horsepower and vehicle velocity.

TRLHP @ Obmph = (A v * Obmph) + (B v * Obmph 2 ) + ( C v * Obmph 3 )
Where: TRLHP = Track Road Load Horsepower.

A v , B v , C v = Coefficients relating TRLHP and velocity.
Obmph = Observed velocity in mph.
(2) Coefficients . A v , B v , and C v are horsepower coefficients from EPA vehicle certification data or EPA default values. Coefficients shall be calculated to a minimum of five significant digits by the following equations. Power fractions determined from track coast-down data shall be calculated to a minimum of two significant digits. In the absence of new car certification coefficients, the default power fractions shall be used.

(A) 

### A A PF 5 0 * (TRLHP ) hp / mph v v @50mph



### =

(B) 

### B B PF 2500 * (TRLHP ) hp / m ph v v @50mph 2



### =

(C) 

### C C PF 125,000 * (TRLH P ) h p / m p h v v @50m p h 3



### =

Where: A v , B v , C v = Coefficients relating TRLHP and velocity.

A v PF, B v PF, and C v PF are power fractions, and indicate the fraction of the total power at 50 mph contributed by each of the A v *50, B v *2500, and C v *125,000 terms.

TRLHP @50mph = Track Road Load Horsepower at 50mph.

(D) A v PF + B v PF + C v PF = 1

Derivation of A v PF, B v PF, and C v PF from known track coastdown curves shall be computed as follows:

(E) 

# ( )( )( ) A PF A A B* C* v v

vv v 

### = + + * * , 5 0 50 2500 125 000104 (F) 

# ( )( )( ) B PF B * A* B* C* v v

vv v 

### = + + 2500 50 2500 125 000 ,

(G) 

# ( )( )( ) C PF C * A* B* C* v v

vv v 

### = + + 125 000 50 2500 125 000 ,

, Default values:
A v PF = 0.35
B v PF = 0.10
C v PF = 0.55
(3) TRLHP @50mph. In absence of new vehicle certification data, the 50 mph TRLHP shall be selected from the EPA I/M Look-up Table. It is based on the following equation: 

# ( ) TRLHP 0.5 * ETW 32.2 * (V V 550* ET 1 2 2 2



### = − )

Where: ET = Elapsed time for the vehicle on the road to coast down from 55 to 45 mph
ETW = Equivalent Test Weight in pounds

V 1 = Initial velocity in feet/second

V 2 = Final velocity in feet/second105 Appendix I

Derivation of GTRL Coefficients106 Derivation of Dynamometer Tire/Roll Interface Losses

(a) Generic Tire Roll Loss
(1) Tire/Roll Interface Losses . Tire/roll losses include vehicle drive train losses and may be determined on a vehicle and dynamometer roll size specific basis, or using the default values presented below.
Tire losses may be characterized on a vehicle and roll size specific basis by the following equation:

GTRL @ Obmph = (A t * Obmph) + (B t * Obmph 2 ) + © t * Obmph 3 )

Where: GTRL = Generic tire/roll interface losses, in horsepower.

A t , B t , C t are coefficients derived by fitting a third order curve of tire losses, in horsepower, and velocity.
Obmph is the observed velocity in mph.

(A) 

### A 0.76 5 0 * (GTRL ) hp / m ph t8 @ 50m ph-8 

### =

(B) 

### B 0.33 2500 * (G TRL ) hp / m ph t8 @ 50m ph-8 2



### =

(C) 

### C -0.09 125,000 * (GTRL ) h p / m p h t8 @ 50m p h -8 3



### =

Where: A t8 , B t8 , C t8 are coefficients relating tire losses, in horsepower, and velocity on an 8.65 inch twin roll dynamometer.
0.76, 0.33, -0.09 are default 50 mph power fraction values derived from experimental data.

GTRL @50mph-8 = -0.378193 + 0.0033207*DAXWT
DAXWT = (VAXF + VAXE)/2
VAXF = Drive axle weight for a vehicle with a full fuel tank from EPA Certification database.
VAXE = Drive axle weight for a vehicle with an empty fuel tank from EPA Certification database.107 (D) 

### A 0.65 5 0 * (GTRL ) hp / mph t20 @ 50m ph-20 

### =
(E) 

### B 0.48 2500 * (GTRL ) hp / mph t20 @ 50mph -20 2 

### =

(F) 

### C -0.13 125,000 * (G TRL ) h p / m p h t20 @ 50m p h-20 3 

### =

Where: A t 20 , B t , 20 , C t20 are coefficients relating tire losses, in horsepower, and velocity on a 20 inch twin roll dynamometer.
0.65, 0.48, -0.13 are default 50 mph power fraction values derived from experimental data.

GTRL @50mph-20 = 0.241645 + 0.0020844*DAXWT
DAXWT = (VAXF + VAXE)/2
VAXF = Drive axle weight for a vehicle with a full fuel tank from EPA Certification database.
VAXE = Drive axle weight for a vehicle with an empty fuel tank from EPA Certification database.

(2) Look-up Table . The vehicle specific values for GTRL @50mph-8 and GTRL @50mph-20 using default values for 50 mph power fractions are published in the latest version of the EPA I/M Look-up Table.