1 

State of California 

AIR RESOURCES BOARD

CALIFORNIA EXHAUST EMISSION STANDARDS AND TEST PROCEDURES 

FOR 2004 AND SUBSEQUENT MODEL 

HEAVY-DUTY DIESEL ENGINES AND VEHICLES

Adopted: December 12, 2002 

Amended: September 1, 2006

NOTE: The proposed amendments are indicated by underline for additions and 

strikeout for deletions compared to the adopted test procedures. Only those 

portions of the existing language containing the proposed modifications are 

included. All other portions remain unchanged and are indicated by the 

symbol “* * * * *” for reference. A complete set of the adopted test 

procedures (without the proposed amendments) is available at 

http://www.arb.ca.gov/regact/levhdg02/levhdg02.htm . 
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CALIFORNIA EXHAUST EMISSION STANDARDS AND TEST PROCEDURES 

FOR 2004 AND SUBSEQUENT MODEL 

HEAVY-DUTY DIESEL ENGINES AND VEHICLES

The following provisions of Subparts A, I, and N, Part 86, Title 40, Code of 

Federal Regulations, as adopted or amended by the U.S. Environmental Protection 

Agency on the date set forth next to the 40 CFR Part 86 section listed below, and only 

to the extent they pertain to the testing and compliance of exhaust emissions from 

heavy-duty diesel engines and vehicles, are adopted and incorporated herein by this 

reference as the “California Exhaust Emission Standards and Test Procedures for 2004 

and Subsequent Model Heavy-Duty Diesel Engines and Vehicles,” except as altered or 

replaced by the provisions set forth below. 

Part I. GENERAL PROVISIONS FOR CERTIFICATION AND IN-USE VERIFICATION 

OF EMISSIONS. 

Subpart A - General Provisions for Emission Regulations for 1977 and Later 

Model Year New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Engines, 

and for 1985 and Later Model Year New Gasoline-Fueled, Natural Gas-Fueled, 

Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles. 

1. General Applicability. [86.xxx-1] 

* * * * * 

11. Emission standards for diesel heavy-duty engines and vehicles. [§86.xxx-11] 

A. Federal provisions. 

* * * * * 

B. California provisions. 

1. Urban Bus Standards. 

* * * * * 

 

6. Heavy-Duty Diesel Engine Idling Requirements.

6.1 Engine Shutdown System. The requirements in this subsection 

apply to engine manufacturers and original equipment manufacturers, as 

applicable, that are responsible for the design and control of engine and/or 

vehicle idle controls. 

6.1.1 Requirements. Except as provided in subsections 11.B.6.2 

and 3, all new 2008 and subsequent model-year heavy-duty diesel 
3 

engines shall be equipped with an engine shutdown system that 

automatically shuts down the engine after 300 seconds of continuous 

idling operation once the vehicle is stopped, the transmission is set to 

“neutral” or “park”, and the parking brake is engaged. If the parking brake 

is not engaged, then the engine shutdown system shall shut down the 

engine after 900 seconds of continuous idling operation once the vehicle 

is stopped and the transmission is set to “neutral” or “park.” The engine 

shutdown system must be tamper-resistant and non-programmable. A 

warning signal, such as a light or sound indicator inside the vehicle cabin, 

may be used to alert the driver 30 seconds prior to engine shutdown. The 

engine shutdown system must be capable of allowing the driver to reset 

the engine shutdown system timer by momentarily changing the position 

of the accelerator, brake, or clutch pedal, or other mechanism within 30 

seconds prior to engine shutdown. Once reset, the engine shutdown 

system shall restart the engine shutdown sequence described in this 

paragraph above, and shall continue to do so until the engine shuts down 

or the vehicle is driven. 

6.1.2 Engine Shutdown System Override. The engine 

shutdown system may be overridden, to allow the engine to run 

continuously at idle, only under the following conditions: 

(1) If the engine is operating in power take-off (PTO) mode. 

The PTO system shall have a switch or a setting that can be 

switched “on” to override the engine shutdown system and will 

reset to the “off” position when the vehicle’s engine is turned off or 

when the PTO equipment is turned off. Subject to advance

Executive Officer approval, other methods for detecting or 

activating PTO operation may be allowed; or, 

(2) if the vehicle’s engine coolant temperature is below 60°F. 

 The engine shutdown system shall automatically be activated once 

the coolant temperature reaches 60°F or above. The engine 

coolant temperature shall be measured with the engine’s existing 

engine coolant temperature sensor used for engine protection, if so 

equipped. Other methods of measuring engine coolant

temperature may be allowed, subject to advance Executive Officer 

approval. 

 (3) if an exhaust emission control device is regenerating,

and keeping the engine running is necessary to prevent 

aftertreatment or engine damage, the engine shutdown system 

may be overridden for the duration necessary to complete the 

regeneration process up to a maximum of 30 minutes. 

Determination of what constitutes the need for regeneration will be 

based on data provided by the manufacturer at time of certification.

 Regeneration events that may require longer than 30 minutes of 

engine idling to complete shall require advance Executive Officer 

approval. At the end of the regeneration process, the engine 
4 

shutdown system shall automatically be enabled to restart the 

engine shutdown sequence described in subparagraph 11.B.6.1.1.

above. A vehicle that uses a regeneration strategy under engine 

idling operating conditions shall be equipped with a dashboard 

indicator light that, when illuminated, indicates that the exhaust 

emission control device is regenerating. Other methods of 

indicating that the exhaust emission control device is regenerating 

may be used with advance Executive Officer approval.

(4) if servicing or maintenance of the engine requires 

extended idling operation. The engine’s electronic control module 

may be set to temporarily deactivate the engine shutdown system 

for up to a maximum of 60 minutes. The deactivation of the engine 

shutdown system shall only be performed with the use of a 

diagnostic scan tool. At the end of the set deactivation period, the 

engine’s electronic control module shall reset to restart the engine 

shutdown system sequence described in subparagraph 11.B.6.1.1

above. 

 

6.2 Exempt Vehicles. Heavy-duty diesel engines to be used in buses 

as defined in California Vehicle Code §§ 233, 612 and 642, school buses as 

defined in California Vehicle Code § 545, recreational vehicles as defined in 

Health and Safety Code 18010, medium duty vehicles as defined in § 

1900(b)(13) of title 13, California Code of Regulations (CCR), military tactical 

vehicles as defined in §1905 of title 13, CCR, and authorized emergency 

vehicles as defined in California Vehicle Code § 165 are exempted from 

these requirements.

6.3 Optional NOx Idling Emission Standard. In lieu of the engine 

shutdown system requirements specified in subsection 11.B.6.1 above, an 

engine manufacturer may elect to certify its new 2008 and subsequent 

model-year heavy-duty diesel engines to an optional NOx idling emission 

standard of 30 grams per hour. Compliance with this optional standard will 

be determined based on testing conducted pursuant to the supplemental 

NOx idling test cycle and procedures specified in section 86.1360-2007.B.4 

below. The manufacturer may request an alternative test procedure if the 

technology used cannot be demonstrated using the procedures in section 

86.1360-2007.B.4, subject to advance approval of the Executive Officer. 

Manufacturers certifying to the optional NOx idling standard must not 

increase emissions of CO, PM, or NMHC, determined by comparing results 

from the supplemental NOx idling test cycle and procedures specified in 

section 86.1360-2007.B.4 below, to emission results from the idle mode of 

the supplemental steady state test cycle or emission results from idle portions 

of the transient test cycle for heavy duty diesel engines, respectively specified 

in sections 86-1360-2007 and 86.1327-98, below. With advance Executive 

Officer approval, a manufacturer may use other methods of ensuring that 
5 

emissions of CO, PM, and NMHC are not adversely affected in meeting the 

optional NOx requirement. Also, manufacturers shall state in their application 

for certification that meeting the optional NOx idling requirement will not 

adversely affect the associated emissions of CO, PM and NMHC.

An engine manufacturer certifying its engine to the optional NOx idling 

emission standard must also produce a vehicle label, as defined in 

subsection 35.B.4, below. 

(D) Optional Alternatives to Main Engine Idling. All new 2008 and 

subsequent model year heavy duty diesel engines may also be equipped with 

idling emission reduction devices that comply with the compliance 

requirements specified in title 13, CCR section 2485(c)(3). 

* * * * * 

12. Alternative certification procedures. [§86.080-12] April 17, 1980. [No change.] 

* * * * * 

21. Application for certification. [§86.xxx-21] 

A. Federal provisions. 

* * * * * 

B. California provisions 

1. For 2004 and subsequent model-year medium-duty ultra-low emission 

and super-ultra-low emission vehicles and engines not powered exclusively by 

diesel fuel, the manufacturer shall submit projected California sales and fuel 

economy data two years prior to certification. 

2. Heavy-Duty Diesel Engine Idling Requirements. 

2.1 For 2008 and subsequent model-year heavy-duty diesel engines, 

the manufacturer must provide a statement in the application for certification 

that the heavy-duty diesel engine for which certification is being requested will 

comply with the automatic engine shutdown requirements to control idle 

emissions as specified in subsection 11.B.6.1. If the heavy-duty diesel 

engine for which certification is being requested is explicitly designed for 

exempt vehicles, per the provisions in 11.B.6.2, then the manufacturer must 

also provide a statement in its application for certification so stating. 

2.2 A manufacturer that elects to certify engines to the optional NOx 

idling emission standard, specified in subsection 11.B.6.3, must provide in the 

application for certification information pertaining to the NOx idling emission 

certification test conducted under 86.1360-2007.B.4, below, including 

emissions data for total particulate matter, non-methane hydrocarbons or 

total hydrocarbons, oxides of nitrogen, carbon monoxide, and carbon dioxide 

in grams per hour, the test load in brake-horsepower, and engine test speeds 

in revolutions per minute for both mode 1 and mode 2 testing. With advance
6 

Executive Officer approval, a manufacturer may use an alternative procedure 

to show compliance with the optional NOx idling emission standard. 

Regardless of the procedure used, the manufacturer shall also provide the 

appropriate labels to be affixed to the vehicle on which the engine is going to 

be installed as required in subsection 35.B.4, below. The manufacturer must 

maintain records at the manufacturer’s facility that contain all test data, 

engineering analyses, and other information which provide the basis for the 

compliance statement, where such information exists. The manufacturer 

must provide such information to the Executive Officer within 30 days upon 

request.

2.3 If the heavy-duty diesel engine for which certification is being 

requested incorporates any of the alternative idle emission control strategies 

contained in title 13, CCR, section 2485(c)(3), then the manufacturer must 

provide in its application for certification a description of the alternative 

strategy or technology including the type, brand name, model identification 

number, and where applicable emissions data and power rating. In addition, 

the manufacturer must also provide the appropriate labels to be affixed to the 

outside of the vehicle as required in subsections 35.B.4. If the alternative 

technology is a fuel-fired heater, then the manufacturer must provide with the 

application for certification the information required under subsection H.4.4, 

Part I of the “California Exhaust Emission Standards and Test Procedures for 

2001 and Subsequent Model Passenger Cars, Light-Duty Trucks and 

Medium-Duty Vehicles,” as incorporated by reference in title 13, CCR, section 

1961(d).

22. Approval of application for certification; test fleet selections; determinations of 

parameters subject to adjustment for certification and Selective Enforcement Audit, 

adequacy of limits, and physically adjustable ranges. [§86.001-22] 

April 6, 1994. [No change.] 

* * * * * 

35. Labeling. [§86.xxx-35] ,

A. Federal Provisions. 

1. §86.001-35 January 18, 2001. 

1.1 Add the following sentence to the introductory paragraph: The 

labeling requirements of this section shall apply to all new motor vehicle 

engines certified according to the provisions of California Health and Safety 

Code Section 43100. 

1.2 Subparagraphs (a)(1) through (a)(3)(iii)(G). [No change.] 

1.3 Amend Add the following language to subparagraph (a)(3)(iii)(H) as 

follows: . 

 1.3.1 An unconditional statement of compliance with the appropriate 

model year California regulations; for example, “This engine conforms to 
7 

California regulations applicable to XXXX model year new heavy-duty diesel 

engines.” It may also state that the engine conforms to any applicable 

federal or Canadian emission standards for new heavy-duty diesel engines. 

1.3.21 For 2004 through 2006 model year heavy heavy-duty dieselfueled, dual-fuel, and bi-fuel engines to be used in urban buses that are 

certified to the optional reduced emission standards and are sold to any 

transit agency exempted under paragraphs (c)(8) and (d)(7), title 13, CCR, 

§1956.2 from the requirements of paragraphs (c)(5) and (d)(4), title 13, 

CCR §956.2. 

“This engine conforms to California regulations applicable to 

XXXX model year new urban bus or heavy-duty diesel engines 

and is certified to a NOx plus NMHC optional reduced-emission 

standards of XXX g/bhp-hr (for optional reduced-emission 

standards specify between 0.3 and 1.8, inclusive, at 0.3 b/bhphr increments, and a particulate matter standards of 0.01 g/bhphr).” 

1.3.32 For all other 2004 through 2006 model year heavy-duty diesel 

cycle engines, including those used in urban buses, that are certified to 

the optional reduced-emission standards, the label shall contain the 

following statement: 

“This engine conforms to California regulations applicable to 

XXXX model year new (specify urban bus or heavy-duty diesel) 

engines and is certified to a NOx plus NMHC optional reducedemission standards of XXX g/bhp-hr (for optional reducedemission standards specify between 0.3 and 1.8, inclusive, at 

0.3 b/bhp-hr increments, and a particulate matter standard of 

0.03 g/bhp-hr, 0.02 g/bhp-hr, or 0.01 g/bhp-hr).” 

1.4 Subparagraphs (a)(3)(I) through (i). [No change.] 

2. §86.007-35. January 18, 2001. 

2.1 Subparagraphs (a) through (i). [No change except that the 

amendments set forth in §86.001-35 apply.] 

B. California provisions. 

1. For 2004 and later model year heavy-duty diesel engines certified under 

the requirements of title 13, CCR, §1956.8(a)(3), the statement of compliance 

requirements of this subsection shall be repeated for each of the two fueling 

modes of operation. Appended to the statement for the lower emitting fueling 

mode of operation shall be the following sentence: 

“This certification is valid only while operating on ___ (indicate the fuel or 

fuel combination under which this mode of operation was certified) fuel. 

Operation using any other fueling mode will result in significant increases 

in exhaust emissions and significantly reduce engine performance.” 
8 

2. Manufacturers may elect to use a supplemental label in addition to the 

original label if there is not sufficient space to include all the required information. 

 The supplemental label must conform to all specifications as the original label. 

In the case that a supplemental label is used, the original label shall be 

numbered “1 of 2” and the supplemental label shall be numbered “2 of 2.” 

3. Statements shall not be used on labels placed on engines that, in fact, do 

not comply with all applicable California regulations. 

4. Vehicle Labels for Heavy-Duty Diesel Engine Idling Requirements. 

For each 2008 and subsequent model year heavy-duty diesel engine certified to 

the optional NOx idling emission standard pursuant to paragraph 11.B.6.3 or 

equipped with a certified/verified auxiliary power system (APS) pursuant to title 

13, CCR, section 2485(c)(3)(A), a single label shall be produced and affixed, as 

applicable, on each vehicle equipped with such heavy-duty diesel engine. 

4.1 The labeling requirements for engine manufacturers, aftermarket 

APS manufacturers and installers, and original equipment manufacturers are 

as follows: 

4.1.1 Engine manufacturers. The engine manufacturer that has 

certified an engine to the optional NOx idling emission standard pursuant 

to paragraph 11.B.6.3, or certified/verified an APS pursuant to title 13, 

CCR, section 2485(c)(3)(A), shall produce the appropriate label for each 

new engine or APS pursuant to paragraph 35.B.4.2, below. The label 

shall be affixed on the outside of the vehicle pursuant to paragraph 

35.B.4.3 by the original equipment manufacturer.

4.1.2 Aftermarket APS manufacturers and installers. An 

aftermarket APS manufacturer that has certified/verified an APS pursuant 

to title 13, CCR, section 2485(c)(3)(A), shall produce the appropriate label 

for each APS system pursuant to paragraph 35.B.4.2, below. The label 

shall be affixed on the outside of the vehicle pursuant to paragraph 

35.B.4.3 by the party that is responsible for installing the APS on the 

vehicle. 

4.1.3 Original equipment manufacturer. An original equipment 

manufacturer that has certified an engine to the optional NOx idling 

emission standard pursuant to paragraph 11.B.6.3, or certified/verified an 

APS pursuant to title 13, CCR, section 2485(c)(3)(A), shall produce and 

affix the appropriate label on the outside of the vehicle pursuant to 

paragraphs 35.B.4.2 or 35.B.4.3, whichever is applicable. 

4.2 Label Format. Figure 1 shows a facsimile of the label format for 

an engine certified to the optional NOx idling emission standard pursuant to 

paragraph 11.B.6.3. Figure 2 shows a facsimile of the label format for an 

engine in a certified/verified APS pursuant to title 13, CCR, section 

2485(c)(3)(A). The engine manufacturer, APS manufacturer or original 

equipment manufacturer, whichever is applicable, that produces and affixes 

the label on the vehicle must ensure that the label has the following 
9 

characteristics:

 Figure 1 Figure 2

4.2.1 Oval shape. 

4.2.2 Dimensions of no less than 6 inches wide by 4 inches high. 

4.2.3 The color of the outer and inner ellipses shall be dark blue

and the stars in red. The background of the label shall be light blue in 

color. The size of the stars shall be equal to the size of the characters as 

specified in paragraph 35.B.4.2.4 below. 

4.2.4 A vehicle equipped with an engine that is certified pursuant 

to paragraph 11.B.6.3 shall have a label with the word “CERTIFIED,” and 

below it the phrase “CLEAN IDLE,” as shown in Figure 1. A vehicle 

equipped with an APS certified/verified pursuant to title 13, CCR, section 

2485(c)(3)(A) shall have a label with the word “VERIFIED,” and below it 

the phrase “CLEAN APS,” as shown in Figure 2. The label information 

shall be written in the English language with sans serif font, black in color,

and in upper case letters. The size of the font shall be at least 7/16 inch 

(or 32 points) and the spacing of the fonts must be such that the longest 

phrase (for example, “CLEAN IDLE”) extends from the left edge to the 

right edge of the inner edge of the inner ellipse, without touching the 

edges. The label information shall be centrally aligned, both vertically and 

horizontally. 

4.2.5 A hologram as shown in Figure 3 shall be embedded within 

the proposed label. The hologram must cover the entire label. The 

hologram shall have the phrase “Clean Skies” repeatedly written from 

edge to edge of the label boundaries and each phrase shall be separated 

by a circular bullet. The position of the circular bullet in each line shall be 

exactly above the space between the words “Clean” and “Skies” of the line 

below. The color of the font shall be orange. The font size“ shall be less 

CERTIIFIIED

CLEAN IIDLE

VERIIFIIED

CLEAN APS
10 

than or equal to a quarter of the font size of the phrase “CLEAN IDLE” or 

“CLEAN APS” as specified in subsection 35.B.4.2.4, above. The 

hologram shall have the map of the State of California, in orange color, 

overlaid over the text and positioned in the center of the label as shown in 

Figure 3, below.

Figure 3

 4.3 Label Location and Attachment Requirements

4.3.1 The appropriate label shall be permanently affixed to the 

exterior on the driver’s side of the hood, in an area within one foot by one 

foot from the top and front edges of the hood. If such an attachment is 

not feasible, the label may be attached at a different location subject to 

advance approval by the Executive Officer. 

4.3.2 Each label must be affixed in such a manner that it can not 

be removed without destroying or defacing the label. The label must not 

be affixed to any vehicle component that can easily be detached from the 

vehicle. 

 4.3.3 The label and any adhesives used must be designed to 

withstand, for a period of 10 years, typical environmental conditions. 

Typical environmental conditions include, but are not limited to, exposure 

to extreme heat or cold, moisture, engine fuels, lubricants and coolants. 

 4.4 The party that certifies/verifies the engine pursuant to paragraph 

11.B.6.3 or the APS pursuant to title 13, CCR, section 2485(c)(3)(A) shall be 

the ultimate party responsible for ensuring that the labels are correctly 

produced. Samples of labels produced pursuant to this subsection must be 

submitted to the Executive Officer with the applicable certification or 

verification application. 

4.5 Labels on vehicles may also be applied by original equipment 

manufacturers, distributors, or dealers. However, the party that certified the 

engine or the APS and produced the labels remains the ultimate party 

responsible for ensuring that the labels are correctly administered. If the 
11 

labels are administered by the original equipment manufacturer, dealer, or 

distributor, the producer of the label shall include its name and a serial 

number on the label. The location of the producer’s name and serial number 

on the label shall be written in the lower part of the label, in the space 

vertically centered between the label wording and the inner ellipses, and the 

font must contrast the label background. The serial numbers of the labels 

administered must be recorded by the original equipment manufacturer,

distributor, or dealer and reported to the party responsible for producing the 

labels. This information shall be maintained by the party responsible for 

producing the labels for a period of 10 years, and shall be made available to 

the Executive Officer upon request. 

4.6 A heavy-duty diesel engine that has been certified pursuant to 

subsection 11.B.6.3 shall not be modified or altered unless said modification 

or alteration has been approved by the Executive Officer pursuant to title 13 

CCR sections 2220 through 2225. 

4.7 An idling emission reduction device or system that has been 

certified/verified pursuant to title 13, CCR, section 2485(c)(3)(A) shall not be 

modified or altered unless said modification or alteration has been approved 

by the Executive Officer pursuant to title 13 CCR sections 2470 through 

2476.

36. Submission of vehicle identification numbers. [§86.079-36] [n/a] 

* * * * * 
12 

PART II TEST PROCEDURES 

Subpart I - Emission Regulations for New Diesel-Fueled Heavy-Duty Engines; 

Smoke Exhaust Test Procedure 

* * * * * 

Subpart N - Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty 

Engines; Gaseous and Particulate Exhaust Test Procedures 

* * * * * 

86.1360-2007 Supplemental steady-state test; test cycle and procedures. 

January 18, 2001. 

A. Federal provisions 

* * * * * 

B. California provisions 

1. Emission testing caps for the 2005 and subsequent model years. 

* * * * * 

4. Determination of NOx Idling Emissions. The requirements set forth in 

this subparagraph apply to 2008 and subsequent model year heavy-duty diesel 

engines certifying to the optional NOx idling emission standard specified in 

subsection 11.B.6.3, above. To determine whether an engine meets the optional 

NOx idling emission standard, emissions shall be measured by testing the 

engine on an engine dynamometer as described below.

4.1 Test Cycle. The following 2 mode duty cycle shall be performed 

on a dynamometer on the test engine:

Mode Engine Speed 

(rpm)

Time in mode 

(seconds) Engine Load

1

Manufacturer 

Recommended Curb idle 1800

See 

subparagraph 4.1.1

below

2 1100 1800

See 

subparagraph 4.1.2

below

4.1.1 For mode 1, the dynamometer load or torque applied shall 

be based on the vehicle power requirements during curb idle operation. 
13 

The engine manufacturer shall determine the curb idle speed and the 

appropriate test load for the test engine. The load shall include curb idle 

power requirements needed for operating engine accessories, such as the 

engine cooling fan, alternator, coolant pump, air compressor, engine oil 

and fuel pumps and any other engine accessory operated during curb idle 

of the engine. The load for mode 1 may not include power requirements 

for operating the air conditioning compressor or for operating on-board 

accessories, such as a microwave, refrigerator, television, computer, etc., 

that the vehicle operator may use during rest periods.

4.1.2 For mode 2, the dynamometer load or torque applied shall 

be based on the vehicle power requirements during idle speed operations 

of 1100 revolutions per minute (rpm). The engine manufacturer shall 

determine the appropriate test load for the test engine. The load shall 

include high engine idle speed power requirements needed for operating 

engine accessories, such as the engine cooling fan, alternator, coolant 

pump, air compressor, engine oil and fuel pumps, air conditioning 

compressor set at maximum capacity, and any other engine accessory 

operated during the idle operation of the engine. The total test load shall 

be equal to the test load so determined plus an additional load of 2 

kilowatts to take into account the power needs for operating on-board 

accessories such as a television, refrigerator, microwave, computer, etc. 

4.2 Test Requirements.

4.2.1 Pre-conditioning. Prior to measuring emissions, bring the 

engine to a warm condition as follows: 

(a) If the idling test follows directly after testing over the 

Federal Test Procedure or the supplemental emission tests, 

consider the engine warm. Bring down the engine to the 

manufacturer recommended curb idle speed, apply the appropriate 

load as determined in subparagraph 4.1.1, and start measuring 

emissions after 10 minutes and only after achieving temperature 

stability. Temperature stability may be determined as the point at 

which the engine coolant temperature is within 2% of its mean value 

for at least 2 minutes. 

(b) If the engine is cold, warm-up the engine by operating it at 

any speed above peak-torque speed and between 65 to 85% of 

maximum mapped power until the engine coolant’s temperature is 

within 2% of its mean value for at least 2 minutes or until the engine 

thermostat controls engine temperature. 

4.2.2 Test Sequence. Following engine warm-up as described in 

subparagraph 4.2.1, the test shall be performed first for mode 1. Bring 

down the engine to the curb idle speed, apply the appropriate load as 

determined in subparagraph 4.1.1, and start measuring emissions after 10 

minutes and only after achieving temperature stability. Temperature 

stability may be determined as the point at which the engine coolant 

temperature is within 2% of its mean value for at least 2 minutes. Upon 
14 

completion of mode 1 testing, the engine speed shall be ramped up to 

1100 rpm. Once the engine starts operating at 1100 rpm, apply the 

appropriate load as determined in subparagraph 4.1.2, and start 

measuring emissions after 10 minutes and only after achieving 

temperature stability. Temperature stability may be determined as the 

point at which the engine coolant temperature is within 2% of its mean 

value for at least 2 minutes. The engine shall be operated for the 

prescribed time in each mode. The specified test speed shall be held to 

within ±50 rpm and the specified torque shall be held to within ±2 percent

of the maximum torque at the test speed. 

4.2.3 Calculations. For each test mode, calculate the modal 

average mass emissions level for each regulated pollutant, in grams per 

hour, the modal average power, in brake horsepower and the modal 

average speed, in rpm. For compliance, the calculated average NOx 

emissions of each mode shall not exceed the optional NOx idling emission 

standard of 30 grams per hour specified in subsection 11.B.6.3 above.

86.1370-2007 Not-To-Exceed test procedures. January 18, 2001. 

* * * * *