Future Policy forMotor Vehicle Emission Reduction(Fourteenth Report)

August 19, 2020

Expert Committee on Motor Vehicle Emissions,
Air, Noise, and Vibration Committee
Central Environment Council

Future Policy for Motor Vehicle Emission Reduction (Fourteenth Report)
Table of contents
Page
1. Introduction .......................................................................................................................... 1
1.1 Background to motor vehicle emission regulation in Japan and history of
discussions at the Central Environment Council ............................................................ 1
1.2 Standpoints in discussions of motor vehicle emission reduction measures........ 4
2. Measures for Fine Particulate Matter, etc. ...................................................................... 6
2.1 State of air quality in relation with fine particulate matter ....................................... 6
2.2 Background to regulations on particulate matter in Japan ..................................... 7
2.3 Background to regulations on particulate matter in the United Nations, etc. ...... 8
2.4 Technology for reducing PM emission from vehicles, etc. ..................................... 9
2.5 Consideration of PM emission measurement ........................................................ 10
2.6 Allowable maximum desired values for emissions and application start time ... 10
3. Measures to Reduce Emissions from Special Motor Vehicles .................................. 11
3.1 Test cycles for special motor vehicles ..................................................................... 11
3.2 Transient modes, etc. for gasoline/LPG special motor vehicles in the U.S. andEurope ................................................................................................................................. 11
3.3 Consideration of introduction of transient modes, etc. for gasoline/LPG special
motor vehicles .................................................................................................................... 12
3.4 Allowable maximum desired values for emissions and application start time ... 13
3.5. Measures to reduce blow-by gas ............................................................................ 13
4. International Harmonization of Emission Test Methods for Passenger Cars, etc.
.................................................................................................................................................. 14
4.1 Trends in international harmonization of emission tests, etc. .............................. 14
4.2 Consideration of introduction of test cycles applied to WLTC Class 1 and Class
2 vehicles ............................................................................................................................ 14
4.3 Application start time .................................................................................................. 15
5. Future Policy for Motor Vehicle Emission Reduction .................................................. 16

5.1. Issues to be considered in the future...................................................................... 16
5.1.1 Measures for fine particulate matter, etc. ........................................................ 16
5.1.2 Measures for brake dust and tire dust.............................................................. 16
5.1.3 Measures to reduce fuel evaporative emissions ............................................ 17
5.1.4 Review of regulations on idling emissions ....................................................... 18
5.1.5 Introduction of on-road inspections, etc. .......................................................... 18
5.1.6 Introduction of low-temperature tests and high-temperature tests .............. 19
5.1.7 Measures to reduce emissions from gasoline/LPG heavy-duty vehicles ... 19
5.1.8 Measures to reduce emissions from special motor vehicles ........................ 20
5.1.9 Effect of fuel properties on emissions .............................................................. 21
5.1.10 Measures on other non-regulated substances ............................................. 22
5.2 Leading the international harmonization of technical standards for motor vehicle
emission reduction............................................................................................................. 22
5.3 Measures, etc. related to policy for motor vehicle emission reduction ............... 23
5.3.1 Promoting a comprehensive policy for motor vehicle emission reduction.. 23
5.3.2 Promotion of eco-friendly motor vehicles......................................................... 24
5.3.3 Assessing the state of air quality and forecasting the effects of improvement.......................................................................................................................................... 25
5.3.4 Continuous assessment of the costs and effects of measures .................... 26
5.3.5 Research system improvement and securing of human resources for motor
vehicle emission reduction ........................................................................................... 26
5.4 Measures responding to changes in environment surrounding motor vehicles 26
Attached Figure 1 .................................................................................................................. 28
Attached Figure 2 .................................................................................................................. 29
Attached Table 1 .................................................................................................................... 31
Attached Table 2 .................................................................................................................... 32
Attached Table 3 .................................................................................................................... 33
Glossary .................................................................................................................................. 34

1. Introduction
1.1 Background to motor vehicle emission regulation in Japan and history of
discussions at the Central Environment Council
Motor vehicle emission controls, aimed at further improvement of air quality in Japan,
began in 1966 with the adoption of a regulation limiting the concentration of carbon
monoxide (hereinafter referred to as “CO”) emissions from ordinary-sized motor
vehicles*1 and small-sized motor vehicles*2 using gasoline for fuel. Since then, thecountry has successively enhanced controls on motor vehicle emissions, taking into
account the state of air pollution, technological developments trends, and trends inoverseas regulations. Currently, regulations are implemented by fuel type, such as
gasoline, liquefied petroleum gas (hereinafter referred to as “LPG”) , and diesel, andby category of motor vehicle, such as ordinary-sized motor vehicles, small-sized motor
vehicles, light motor vehicles*3, motorcycles*4, motor-driven cycles*5, and special
motor vehicles.*6
With regard to the motor vehicle emission reduction measures taken in recent years,
it was in May 1996 that the Director-General of the Environment Agency sent a request
to the Central Environment Council to formulate recommendations for Future Policy forMotor Vehicle Emission Reduction (inquired in May 1996). In response, deliberations
were held within the Air Environment Committee (present-day Air, Noise, and Vibration
Committee) of the Central Environment Council, as well as the Expert Committee on
Motor Vehicle Emissions established under the Air Environment Committee.
Among the above categories, for motorcycles and motor-driven cycles (hereinafterreferred to as “two-wheeled vehicles”), emission regulations have been implemented
since October 1998 on the basis of the Interim Report (compiled by the Central
Environment Council in October 1996). In addition, the 2006 Regulation have been
implemented since October 2006 based on the Sixth Report (compiled by the Central
Environment Council in June 2003), with more stringent regulation values on CO,hydrocarbons (hereinafter referred to as “HC”), and nitrogen oxides (hereinafterreferred to as “NOx”). Furthermore, the worldwide harmonized test cycles (Worldwide
Motorcycle emissions Test Cycle,

hereinafter referred to as “WMTC”),*7 which were1

established at the World Forum for Harmonization of Vehicle Regulations of the United
Nations Economic Commission for Europe (hereinafter referred to as “UNECE/WP29”) with the participation of Japan, have been introduced on the basis of theEleventh Report (compiled by the Central Environment Council in August 2012) since
October 2012, and the allowable maximum desired values for emissions specified by
WMTC have been adopted since October 2016. Emission regulation values will be
more stringent in December 2020 based on the Thirteenth Report (compiled by theCentral Environment Council in May 2017).
For emissions from gasoline- and LPG-fueled ordinary-sized, small-sized, and lightmotor vehicles (hereinafter referred to as “gasoline/LPG vehicles”), the 2005
Regulation and the 2007 Regulation, or so-called New Long-Term Regulations, havebeen implemented since October 2005 based on the Fifth Report (compiled by theCentral Environment Council in April 2002). In addition, for gasoline/LPG vehicles
equipped with in-cylinder direct injection lean-burn gasoline engines in which occlusion
type NOx reduction catalysts are used (hereinafter referred to as “lean-burn direct
injection vehicles”), the 2009 Regulation, or so-called “Post New Long-Term
Regulations,” have been enforced since October 2009 on the basis of the Eighth
Report (compiled by the Central Environment Council in April 2005), which newly
introduced emission regulation values on particulate matter (hereinafter referred to as“PM”). Subsequently, anticipating the spread of bio-ethanol fuels, the regulation has
been implemented since April 2012 based on the Tenth Report (compiled by theCentral Environment Council in July 2010) on the quality of motor vehicle fuels, suchas 10-volume percent bio-ethanol-blended gasoline subject to so-called E-10 fuelstandards, and on emissions from motor vehicles running on these fuels. Furthermore,
the Twelfth Report (compiled by the Central Environment Council in February 2015)
recommended the adoption of a global technical regulation (hereinafter referred to as“gtr”) on the Worldwide harmonized Light vehicles Test Procedure(hereinafterreferred to as “WLTP”)*9 established for gasoline/LPG vehicles and diesel vehicles
excluding heavy-duty vehicles (hereinafter referred to as “passenger cars, etc.”) by
UN-ECE/WP29 with the participation of Japan and the introduction of the Worldwide
2

Light-duty Test Cycle(hereinafter referred to as “WLTC”),*10 which was adopted in

October 2018. The Thirteenth Report recommended the introduction of PM emission
regulations on all vehicles equipped with in-cylinder direct injection gasoline engines
including vehicles equipped with in-cylinder direct injection gasoline engines in which
combustion takes place at the theoretical air fuel ratio where a three-way catalyst canbe used (hereinafter referred to as “stoichiometric direct injection vehicles”), which will
be enforced in December 2020.
For emissions from diesel-fueled ordinary-sized and small-sized motor vehicles(hereinafter referred to as “diesel vehicles”), the New Long-Term Regulations havebeen implemented since October 2005 on the basis of the Fifth Report. The Post New
Long-Term Regulations have been enforced since October 2009 on the basis of theEighth Report, which strengthened the emission regulation values on NOx and PM.
Moreover, for diesel vehicles with a gross vehicle weight exceeding 3.5 tons
(hereinafter referred to as “diesel heavy-duty vehicles”), the Tenth Report
recommended that it was appropriate to strengthen the allowable maximum desired
value for NOx in 2016 as well as to introduce the Worldwide Harmonized Transient
Cycle(WHTC) *12 and the Worldwide Harmonized Steady state Cycle(WHSC),*13 both of which are part of the Worldwide harmonized Heavy Duty
Certification (WHDC)*11 for diesel heavy-duty vehicles established by UN-ECE/WP29
with the participation of Japan. The test cycles have been adopted since October 2016.
Further, the Tenth Report recommended that it was appropriate to introduce aworldwide harmonized standard for measures in conditions other than a testing mode
which is representative of the driving in the market above, or so-called “off-cycle” (OffCycle Emission;

hereinafter referred to as “OCE”),*14 and to introduce more advanced

on-board diagnostic (OBD) systems.*15 In addition, as measures on emissions fromvehicles in use, durability distance targets largely exceeding past levels have been
implemented starting with vehicles compliant with the 2002 Regulation (New ShortTerm Regulations), based on the Third Report (compiled by the Central Environment
Council in December 1998). Furthermore, on the basis of the Ninth Report (compiledby the Central Environment Council in January 2008), the method of measuring PM
3

emissions was changed from the one based on black smoke contamination measuring
equipment to the one using an opacimeter*16 for vehicles after implementing the Post
New Long-Term Regulations, and allowable maximum desired values were set out.
Additionally, for diesel vehicles with a gross vehicle weight of 3.5 tons or less, as with
their gasoline/LPG counterparts, WLTC, etc. was introduced based on the WLTP-gtr,
and has been applied since October 2018.
For diesel-fueled special motor vehicles (hereinafter referred to as “diesel special
motor vehicles”),*17 emission regulation has been implemented since October 2003
based on the Second Report (compiled by the Central Environment Council in
November 1997) and the Fourth Report (compiled by the Central Environment Council
in November 2000). Further, emission regulation has been tightened since October
2006 on the basis of the Sixth Report. Moreover, the Ninth Report recommended
enhancing regulation values in two phases, i.e., firstly from 2011 and then from 2014,
and replacing the emission test cycle with Non Road Transient Cycle (hereinafterreferred to as “NRTC”)*18 and so on. Based on the above, the 2011 Regulation which
set allowable maximum desired values in accordance with the engine rated output
were implemented in phases between October 2011 and October 2013, andsubsequently the 2014 Regulation have been implemented since October 2014. As
well, based on the Eleventh Report, the method of measuring PM emissions waschanged from the one based on black smoke contamination measuring equipment to
the one using an opacimeter since the 2014 Regulation, and it was determined that
discussions would be held for harmonization with the blow-by gas*20 measures set out
in the worldwide standard for non-road mobile machinery (hereinafter referred to as“NRMM”)*19 established by UN-ECE/WP29. The Eleventh Report also suggested thateither the conventional C1 mode (8-mode) or the new test mode (Ramped Modal
Cycle; hereinafter referred to as “RMC”)*21 could be selected to ensure harmonization
with the NRMM standard for the steady-state test cycle.

1.2 Standpoints in discussions of motor vehicle emission reduction measures
Motor vehicles are developed, certified, and produced in each country and region.
4

Therefore, automobile manufacturers provide different specifications for each
destination in order to comply with regulations of various countries including Japan.
If emission test methods are harmonized internationally, the design specifications formotor vehicles can be unified, which will promote standardization of parts, reduce
development period and production costs, thus lead to the widespread of newtechnology for reducing emissions. Needless to say, it will also help research anddevelopment of emission reduction technology. Thus, automobile manufacturers havebeen expecting the international harmonization of emission test requirements aroundthe world.
Furthermore, it is considered that promoting the international harmonization ofemission test methods is very useful for Japanese automobile manufacturers to ensureinternational competitiveness while maintaining the world’s highest level ofenvironmental technology. Given the situation, as described in 1.1, the Ninth, Tenth,
Eleventh, and Twelfth Reports suggested that emission test methods should beharmonized internationally through the adoption of the worldwide-harmonized test
cycles and other measures for diesel special motor vehicles, diesel heavy-duty
vehicles, two-wheeled vehicles, passenger cars, etc., and such methods are being
introduced one by one.
The Thirteenth Report suggested that in terms of measures for Particulate Matter
2.5(hereinafter referred to as “PM2.5”),*22 the conventional measurement method

under the PM regulations was based on the measurement of the mass of the particles
trapped in the filter, thus the regulation values could not be reduced significantly due
to inadequate measurement accuracy. Therefore, the introduction of regulations for
PM particle number (hereinafter referred to as “PN”) should be considered on diesel
vehicles and gasoline direct injection vehicles while taking into account the degree ofthe achievement of environmental standards in Japan and the actual status of PMemissions.
According to the Thirteenth Report by Expert Committee, regarding gasoline- or
LPG-fueled special motor vehicles (gasoline/LPG special motor vehicles),*23 it isconsidered that the government should consider reviewing the test cycles currently in5place (C2 mode), introducing a transient cycle and taking measures to reduce blow-bygas.
In addition, it is necessary to consider test cycles applied to low-powered passenger
cars, etc. to further promote the international harmonization of emission test methods.
The Expert Committee held in-depth discussions mainly on the above subjects andreached the conclusion stated in Section 2 regarding measures for fine particulatematter, and that stated in Section 3 regarding measures to reduce emissions from
special motor vehicles, and that stated in Section 4 regarding international
harmonization of emission test methods for passenger cars, etc. The Committee also
summarized its opinion about the future policy for motor vehicle emission reduction in
Section 5.

2. Measures for Fine Particulate Matter, etc.
2.1 State of air quality in relation with fine particulate matter
Regarding measures for particulate matter, Japan established environmental
standards in 1973, defining particles with a particle size of 10 µm or less that floated in
the air for relatively long periods of time and were inhaled into the respiratory system
as suspended particulate matter (SPM), and has been taking comprehensive
measures to protect the air environment. Recently, there has been growing concern
about the impact of fine particulate matter with a diameter of 2.5 µm or less (PM2.5)
among the suspended particulate matter, as it can penetrates deep into the respiratory
system and various harmful components are absorbed or attached on the surface ofthe particles. With regard to the health effects of exposure to PM2.5, a number ofscientific findings in epidemiology and toxicology showed that it, as a whole, had
certain influence on human health, including respiratory diseases, circulatory diseases,
lung cancer, etc. Therefore, environmental standards have been implemented on PM2.5
since September 2009, and a nation-wide infrastructure is currently underdevelopment to measure its concentration.
The annual average concentration (hereinafter referred to as “annual average”) has
been gradually decreasing since 2013. The annual averages measured by ambient air
6pollution monitoring stations and roadside air pollution monitoring stations were 11.2
μg/m3 and 12.0 μg/m3 in the fiscal year 2018, respectively. Also, the achievement ofenvironmental standards in the fiscal year 2018 was 93.5% (765 among 818 valid
monitoring stations) for ambient air pollution monitoring stations, and 93.1% (216
among 232 valid monitoring stations) for roadside air pollution monitoring stations.
The contribution of cross-border air pollution to PM2.5 concentrations in Japan is
declining, indicating that the contribution of domestic sources is relatively increasing.
The contribution ratio of domestic sources to PM2.5 concentrations in Japan varies byregion, but in general, fixed sources and the automobile sector mainly contribute toPM2.5 concentrations. Therefore, it is necessary to take comprehensive measures not
only for the automotive sector, but also for fixed sources, etc.

2.2 Background to regulations on particulate matter in Japan
Since most of the particles of PM emitted from motor vehicles are 2.5 µm or smaller
in diameter, a steady execution of the existing emission regulations is directly effective
for the reduction of PM2.5. In Japan, PM regulations on diesel vehicles were introduced
for the first time by the Short-Term Regulations in 1993. Moreover, some lean-burn
direct injection gasoline vehicles equipped with an occlusion type NOx reduction
catalyst were found to emit an equivalent or a greater amount of PM compared to diesel
vehicles equipped with a diesel fine particulate removal device (diesel particulate filter;
hereinafter referred to as “DPF”).*24 Therefore, based on the above, it was suggested
in the Eighth Report that the allowable maximum desired value for PM emissions
should be set only for lean-burn direct injection vehicles equipped with an occlusion
type NOx reduction catalyst at the same level as that of diesel vehicles to reduce their
PM emissions, and the regulation has been implemented since 2009. Moreover, thePM emissions from stoichiometric direct injection vehicles are greater in volume than
the PM emissions from diesel passenger cars*25 on which the regulation has been
implemented already. Therefore, it was suggested in the Thirteenth Report that theallowable maximum desired value for PM emissions should be set for stoichiometricdirect injection vehicles at the same level as those of diesel vehicles and lean-burn7

direct injection vehicles to reduce their PM emissions, and the regulation will be
implemented in December 2020.

2.3 Background to regulations on particulate matter in the United Nations, etc.
In the United Nations, the PM regulations for heavy-duty vehicles (including gasoline
vehicles) and for diesel vehicles have been set forth in the UN Regulation No.49 02
Series enforced in 1992 and in the UN Regulation No.83 01 Series enforced in 1992,
respectively. In addition, as for the UN Regulation No.83 06 Series enforced in 2010,
PM regulations were set forth on gasoline direct injection vehicles (including
stoichiometry direct injection vehicles) in the UN regulation at the same level as the
PM regulations on diesel vehicles. In line with these moves to revise the UN
Regulations, PM regulations similar to the UN Regulation have been implemented inEurope.
On the other hand, as the conventional mass method has a limitation in the level ofmeasurement, an informal working group was established under the Working Party on
Pollution and Energy (GRPE) of UN-ECE/WP29 to examine, consider, and evaluate a
new measurement method that would complement or replace the conventional mass
method, with the participation of Japan, the United States and Europe. As a result, it
was concluded that the PN measurement method would be a superior alternative tothe mass method for future regulations and was specified in the UN Regulation.
In response, in Europe, the PN regulations have been introduced since 2011 fordiesel vehicles (excluding heavy-duty vehicles) and since 2012 for diesel heavy-duty
vehicles. In addition, they have been introduced since 2014 for gasoline direct injection
passenger cars and since 2015 for gasoline direct injection small-sized commercial
vehicles.
On the other hand, the United States has announced a plan to substantiallystrengthen the PM regulations with the mass method since 2025, while paying close
attention to the consideration of a new measurement method in the United Nations,and is currently considering how to improve the accuracy of the mass method.

8

2.4 Technology for reducing PM emission from vehicles, etc.
PM emissions from diesel vehicles, which used to be distinctively high, were greatly
reduced by the introduction of DPFs in the 1990s. DPF is a device that traps PM bymaking the exhaust gas pass through a porous filter, etc. Whenever a certain amountof PM accumulates in the filter, the filter temperature is raised to oxidize and remove
the PM.
In vehicles equipped with conventional fuel injection (port injection) gasoline engines,
fuel and air are mixed before entering the combustion chamber. This allows for
sufficient mixing time to attain an evenly mixed air-fuel mixture, which results in
extremely low PM emissions. On the other hand, in direct injection vehicles where fuelis directly injected into the combustion chamber, fuel collides with the wall of the
combustion chamber and the mixing time for air and fuel is shorter compared to port
injection gasoline vehicles, which causes some of air-fuel mixture to become uneven
This makes some sections of the air-fuel mixture too rich, which leads to incomplete
combustion and possible increase in PM emissions. Occasionally in cold start
conditions, injected fuel adheres onto the piston top surface and produces PM throughpool fire.*26 In Europe, to comply with the PN regulations mentioned in Section 2.3,
gasoline particulate filters(GPF)*27 similar to those used in diesel vehicles are put

into practical use for gasoline vehicles, in addition to the measures to improve engine
combustion. Since gasoline vehicles have higher exhaust gas temperatures thandiesel vehicles, they can oxidize and remove PM accumulated in the filter during
normal driving. When the exhaust gas temperature is low due to special driving
conditions, such as repeated low-speed driving in a low-temperature environment, it isnecessary to oxidize and remove PM by raising the filter temperature, just like diesel
vehicles. As for gasoline vehicles where combustion takes place at the theoreticalmixture ratio, there is basically no oxygen in the exhaust gas, and when fuel cut during
deceleration generates a surplus of oxygen, oxygen is provided to the GPF to oxidize
the accumulated PM. Therefore, if the amount of oxygen required for oxidation cannot
be secured due to continuous low speed driving, etc., it is necessary to take measures
to supply the GPF with oxygen necessary for PM oxidation, such as cutting fuel and9introducing secondary air.

2.5 Consideration of PM emission measurement
As the conventional measurement method under the PM regulations is based on themeasurement of the mass of the particles trapped in the filter, the regulation values
cannot be reduced significantly due to inadequate measurement accuracy. On theother hand, the PN measurement method, which removes the volatile components ofPM and counts the number of particles, enables more accurate measurement. As
mentioned in Section 2.3, Europe has introduced stringent regulations that are difficult
to be evaluated by conventional measurement method, and the PN regulations (which
cover particles with a diameter 23 nm or more) have been introduced as the use ofparticulate filters, etc. with high trapping efficiency allows compliance with theregulations. In addition, other countries except Europe have already adopted PN
regulations.
According to the results of research conducted by the Ministry of the Environment
up to the fiscal year 2019, there is a certain degree of correlation between PM mass
and PN. If the current PN regulation values in Europe are converted to PM mass, theemissions will be about one-tenth of the current PM mass regulation values. Therefore,
it is appropriate to introduce PN regulations for diesel vehicles and vehicles equippedwith in-cylinder direct injection gasoline engines, since the introduction of PN
regulations can significantly reduce PM emissions.

2.6 Allowable maximum desired values for emissions and application start time
With regard to the emission test methods including emission test cycles whenintroducing PN regulations in accordance with the policy described in Section 2.5, it isappropriate to apply WHDC including WHTC and WHSC to heavy-duty vehicles (JE05
mode*28 to gasoline heavy-duty vehicles) and WLTP including WLTC to passenger cars,etc.
It is appropriate to make the allowable maximum desired values as strict as feasible,
based on the degree of the achievement of the environmental standards for PM2.5 and10technological developments trends at home and abroad, as shown in Attached Tables
1 and 2.
With regard to the application start time, it is appropriate to commence theapplication by the end of 2024 for gasoline vehicles and by the end of 2023 for diesel
vehicles, in consideration of the period of time required for automobile manufacturers
to develop technologies, etc.

3. Measures to Reduce Emissions from Special Motor Vehicles
3.1 Test cycles for special motor vehicles
Japan regulates emissions from special motor vehicles with an engine output of 19
kW or more but less than 560 kW. Based on the Sixth Report, C2 mode (7-mode),which is a steady-state mode, has been adopted for gasoline/LPG special motor
vehicles since 2007. On the other hand, based on the Ninth Report, NRTC, which is atransient test cycle, has been introduced for diesel special motor vehicles since 2011in addition to C1 mode (8-mode), which is a steady-state mode, and the RMC mode,
which is can be selected instead of C1 mode (8-mode), has been introduced since2014 on the basis of the Eleventh Report.
A three-way catalyst is mainly used to reduce emissions from gasoline/LPG special
motor vehicles, and feedback control is implemented to always maintain an appropriate
air-to-fuel ratio by measuring the residual oxygen concentration in emissions with an
O2 sensor to achieve a high cleaning rate. As the current test cycle for gasoline/LPG
special motor vehicles is a steady-state cycle, it cannot take into consideration timedelay in catalyst temperature caused by transient use and the deterioration of theperformance of the three-way catalyst due to unsteady nature of emissions flowing into
the catalyst. Therefore, it may not properly evaluate emission reduction measurescommensurate with the actual use of the vehicles. For this reason, it is also appropriate
to introduce a transient cycle as a test cycle for the regulations for gasoline/LPG special
motor vehicles in the next term.
3.2 Transient modes, etc. for gasoline/LPG special motor vehicles in the U.S. and11

Europe
As for the transient modes for gasoline/LPG special motor vehicles introduced inother countries, the U.S. has introduced the Large Spark Ignition engines Non-Road
Transient Cycle (LSI-NRTC).*37 In Europe, LSI-NRTC and NRTC have been adopted
for gasoline/LPG special motor vehicles with a rated output of less than 56 kW and forgasoline/LPG special motor vehicles with a rated output of 56 kW or more, respectively.
In terms of steady-state cycles, either C2 mode (7-mode) or 7M-RMC can beselected in the U.S. In Europe, C2 mode (7-mode) and C1 mode (8-mode) have been
introduced for gasoline/LPG special motor vehicles with a rated output of less than 56
kW and for gasoline/LPG special motor vehicles with a rated output of 56 kW or more,
respectively. Based on the above, discussions were held on whether or not it wasappropriate to introduce these transient modes in Japan as well.

3.3 Consideration of introduction of transient modes, etc. for gasoline/LPG special
motor vehicles
Japan developed test cycles based on the actual use of gasoline/LPG special motor
vehicles (JTC)*38 and conducted a comparative test of emissions between JTC and thetransient modes introduced in other countries. As a result, NRTC is not considered tobe appropriate as a test cycle for gasoline special motor vehicles due to its high output
ratio*39 and higher emissions values compared to LSI-NRTC. In addition, comparisonof emissions results from LSI-NRTC and JTC showed that there was a high correlation
between the two test cycles in terms of NOx emissions, with LSI-NRTC giving higher
emission values (g/kWh) than JTC.
Based on these results, it is expected that air quality will be improved and worldwide
harmonization of emission test cycles will be promoted when LSI-NRTC is used as anemission test cycle in Japan. Consequently, it is appropriate to introduce LSI-NRTC
shown in Attached Figure 1 as a transient cycle of the test method in the emission
regulation for special motor vehicles in the next term.
In terms of steady-state cycles, C1 mode (8-mode) is not considered to beappropriate as a test cycle for gasoline/LPG special motor vehicles due to its high12

output ratio and higher emissions values compared to C2 mode (7-mode). It isappropriate to continue to adopt the current C2 mode (7-mode) as some engines
generated more CO and HC emissions (g/kWh) in the current C2 mode (7-mode) thanin LSI-NRTC.
Furthermore, the emissions measured in 7M-RMC met the current regulation values
for all substances and were similar compared to emissions measured in C2 mode (7mode). In light of the above, from the viewpoint of international harmonization oftechnical standards, it is appropriate to introduce 7M-RMC shown in Attached Figure
1 in addition to C2 mode (7-mode) in terms of steady-state tests and to allow for
selection between C2 mode (7-mode) and 7M-RMC at the time of the emission
certification test.
3.4 Allowable maximum desired values for emissions and application start time
Based on the policy described in Section 3.3, the allowable maximum desired values
when introducing LSI-NRTC and 7M-RMC are as shown in Attached Table 3, and it isappropriate to adopt them by the end of 2024.

3.5. Measures to reduce blow-by gas
The release of blow-by gas into the atmosphere has been prohibited for ordinarysized, small-sized, and light motor vehicles, motorcycles, motor-driven cycles, anddiesel special motor vehicles, excluding certain types of vehicles. On the other hand,regulations to ban the release of blow-by gas into the atmosphere are not currently
introduced for gasoline/LPG special motor vehicles.
A survey of the technologies introduced in recent gasoline special motor vehicles
showed that it was technologically possible to prohibit the release of blow-by gas into
the atmosphere. Therefore, it is appropriate to prohibit the release into the atmosphereof blow-by gas emitted from gasoline/LPG special motor vehicles with a rated output
of 19 kW or more but less than 560 kW.
With regard to the application start time, it is appropriate to adopt it by the end of2024, in conjunction with the adoption of the allowable maximum desired values for13

emissions, as described in the Section 3.4.

4. International Harmonization of Emission Test Methods for Passenger Cars, etc.
4.1 Trends in international harmonization of emission tests, etc.
In terms of the test method for passenger cars, etc. in Japan, WLTC developed by
UN-ECE/WP29 with the participation of Japan has been adopted since October 2018,as described in Section 1.1. Vehicles to which WLTC is applied are divided into three
categories based on the value of the maximum power output of a vehicle divided by
the vehicle mass in an unladen state (running order)*40 (Power to Mass Ratio,
hereinafter referred to as “PMR”). They are classified as Class 1, Class 2 and Class 3
in ascending order of PMR, with 22 W/kg and 34 W/kg as the borderlines. Class 3
vehicles are divided into 2 subclasses according to their maximum speed: Class 3avehicles with a maximum speed of less than 120 km/h and Class 3b vehicles with amaximum speed of 120 km/h or more. Base on the above, different test cycles areapplied to each class of vehicle. Among these test cycles, Japan has introduced only
test cycles applied to Class 3a and Class 3b vehicles, which were developed basedon the actual situation of vehicle running in Japan. In terms of the test cycles applied
to Class 1 and Class 2 vehicles, Japan has not introduced the relevant test cycles until
now, as there is almost no actual vehicle driving data in japan and test cycles for thesevehicles have been developed taking into account the actual vehicle driving data inother countries where most vehicles are low-powered and travel at low speed.
On the other hand, UN-ECE/WP29 is now considering the development of a UN
Regulation on WLTP as a new international standard. When the UN Regulation isadopted by Japan and is subject to mutual recognition, it is necessary to introduce not
only the test cycles applied to Class 3a and Class 3b vehicles, but also the test cycles
applied to Class 1 and Class 2 vehicles. Therefore, from the viewpoint of international
harmonization of technical standards, it is necessary to consider whether to introduce
test cycles applied to Class 1 and Class 2 vehicles.

4.2 Consideration of introduction of test cycles applied to WLTC Class 1 and Class 2
14

vehicles
The maximum speed, average speed, and maximum positive acceleration for thetest cycles are set higher for Class 2 vehicles than for Class 1 ones, higher for Class
3a and Class 3b vehicles than for Class 2 ones. The average speed is set higher forClass 3b vehicles than for Class 3a ones.
The test cycle applied to Class 1 vehicles consists of a low-speed phase, a mediumspeed phase and an additional low-speed phase. The test cycles applied to Class 2,
Class 3a and Class 3b vehicles consist of a low-speed phase, a medium-speed phase,a high-speed phase and an extra-high-speed phase. However, the extra-high-speed
phase can be excluded at the option of the contracting parties, and in fact, Japan has
not adopted it in the test cycles applied to Class 3a and Class 3b vehicles.
A survey was conducted about the presence of Class 1 and Class 2 vehicles inJapan, and found that there were no such vehicles among new vehicles on sale inJapan. Therefore, the impact of the test cycle change on the environment is considered
to be very limited.
On the other hand, the introduction of test cycles applied to Class 1 and Class 2
vehicles would allow for the adoption of the UN Regulation, which would reduce theburden on automobile manufacturers and enable more efficient implementation ofenvironmental measures.
Based on the above, the test cycles applied to WLTC Class 1 and Class 2 vehicles
as shown in Attached Figure 2 should be introduced in Japan, and test cycles by
vehicle type as in the UN Regulation should be applied as well. The test cycle applied
to Class 1 vehicles shall consist of a low-speed phase, a medium-speed phase, andan additional low-speed phase, and the test cycle applied to Class 2 vehicles shallconsist of a low-speed phase, a medium-speed phase, and a high-speed phase, aswith the test cycles applied to Class 3a and Class 3b vehicles.

4.3 Application start time
Based on the policy described in Section 4.2, it is appropriate to introduce a test
cycle applied to WLTC Class 1 vehicles and a test cycle applied to WLTC Class 2
15

vehicles for passenger cars, etc. with a PMR not exceeding 22 W/kg, and forpassenger cars, etc. with a PMR exceeding 22 W/kg but not exceeding 34 W/kg,
respectively and to adopt the test cycles by vehicle type as in the UN Regulation in
conjunction with the adoption of the UN Regulation on WLTP.

5. Future Policy for Motor Vehicle Emission Reduction
It is necessary to continue to take measures to reduce vehicle emissions to improve
the air quality in Japan. In doing so, it is expected that the issues described in Section
5.1 and the international harmonization of technical standards in Section 5.2 will be
discussed in consideration of balancing low emission technologies and fuel-efficienttechnologies, in addition to future regulatory effects, technological developments
trends, and contribution to emissions, and that the related measures described in
Section 5.3 will be further promoted to complement the measures.
5.1. Issues to be considered in the future
5.1.1 Measures for fine particulate matter, etc.
Currently, discussions are being held in UN-ECE/WP29 on whether to reduce thelower limit of detection range of the PN measurement method from the current valueof 23 nm to 10 nm in particulate diameter. In addition, the revision of the test method
is being discussed based on the results of round-robin tests*41 to improve the accuracyof the measurement method including a diameter of 23 nm. Japan should continue toparticipate in and contribute to the activities of the United Nations by sharing its
knowledge on the actual status of emissions in Japan, etc. with UN-ECE/WP29, anddiscuss revisions to the test method, etc. considering Japan's environment and impactof vehicle emissions

5.1.2 Measures for brake dust and tire dust
In addition to the emissions from exhaust pipes, PM emissions from motor vehicles
also include fine particles caused by the wear of brakes and tires. As PM in exhaust
pipe emissions has been decreasing due to improved combustion, DPFs, and otherfactors, the relative ratios of brake dust and tire dust to the overall PM emissions are16

on the rise. In addition to holding discussions on the strengthening of exhaust pipe
emissions, UN-ECE/WP29 is therefore working to establish the test methods for brake
dust and tire dust. In particular, test methods for brake dust are studied in detail atvarious research institutes. The United Nations has agreed to develop test methods
for that by 2021. As round-robin tests using the test methods are scheduled to be
conducted in the future, Japan should also actively participate in and contribute to thedevelopment of international standards by cooperating in the round-robin tests andsharing the findings gained through surveys, etc. in Japan with UN-ECE/WP29.

5.1.3 Measures to reduce fuel evaporative emissions
With regard to fuel evaporative emissions during parking, fuel evaporative gas will
be emitted from vehicles due to breakthrough of the adsorption canister*42 especiallywhen a vehicle is parked for a long time. Since three-day parking tests result in bettercost-effectiveness than two-day parking tests with the parking realities in Japan taken
into account, the number of days for the parking test will possibly be increased to threedays in the future so that vehicles can be parked for longer periods of time without
emitting fuel vapors. In recent years, instead of installing a canister with larger capacity,
the adoption of an airtight fuel tank is becoming more popular especially for hybrid
vehicles, etc. in which purging is difficult. The valve opening pressure for the vent valve
is set sufficiently high on vehicles with airtight tanks to prevent vapor emissions fromthe tanks even in a high temperature environment. While grasping the latest
technological developments such as canisters with larger capacity and airtight tanks,
the Japanese government should also actively participate in and contribute to thereviewing of international standards by sharing survey findings, etc. with UNECE/WP29.
Moreover, regarding the temporary emissions of fuel vapors that occur dependingon the internal pressure of the tank when the fuel cap is opened (hereinafter referred
to as “puff loss”), vehicles with airtight tanks have a mechanism to suppress theseemissions, for which discussions are being held to establish test methods underinternational standards. On the other hand, discussions are not being held for the puff
17

loss emissions from vehicles equipped with conventional tanks. It is believed that eventhe puff loss from vehicles with conventional tanks can be reduced by opening thevalve between the tank and the canister prior to opening the fuel cap. Therefore, while
taking into account the amount of puff loss emissions from vehicles with conventionaltanks and the costs required for implementing measures, discussions should be heldon the establishment of standards for these emissions in addition to the strengtheningof the number of days for the parking test as described above, with the perspective ofinternational harmonization of technical standards.

5.1.4 Review of regulations on idling emissions
With regard to regulations on idling emissions, the abolition of the HC regulation andthe strengthening of the regulation on four-wheeled vehicles were put on agenda for
discussion in the Thirteenth Report. With regard to the former issue, field surveys of
HC and CO emissions in Japan showed no correlation between CO and HC emissions,and therefore a conclusion of abolishing the HC regulation was not reached.
On the other hand, the strengthening of regulations on four-wheeled vehicles should
be discussed, based on the current status of reviewing the reclassification of UN
regulations on emissions, while accurately assessing the movements in the future andreevaluating the actual emissions and the development of measuring instruments andtheir spread.

5.1.5 Introduction of on-road inspections, etc.
In September 2015, the diesel passenger cars and other vehicles manufactured by
Volkswagen (VW) were found to be using illegal software. Specifically, the diesel
vehicles sold by VW in Europe, the United States, and other regions had illegal
software installed which activated the emission reduction device only when driven incertain running modes on the test bench for new-vehicle inspection. On the other hand,the software stopped or weakened the emission reduction device in on-road conditions.
In response to this scandal, from October 2015, discussions were held on thereviewing, etc. of the emission test methods for diesel passenger cars and other18

vehicles in the “Investigative Committee for Reviewing the Inspection Methods forDiesel Passenger Cars in Response to Illegal Emission Control” (a committee jointly
established by the Ministry of Land, Infrastructure, Transport and Tourism and theMinistry of the Environment). The final summary published on April 20, 2017
recommended that it was appropriate to introduce the guidelines for safety control andon-road inspections in 2022. In response to this, the relevant laws and regulations wereamended in March 2018 and will be enforced in October 2022.
Based on the introduction of PN regulations as described in Section 2, the necessityof introducing PN regulations for on-road inspections should be discussed in the future,including field surveys, etc., from the viewpoint of international harmonization oftechnical standards.
Moreover, it is appropriate to review the calculation methods, including the emission
intensity used in calculating the overall emissions, by making corrections based on the
postulation of real-life driving, etc.

5.1.6 Introduction of low-temperature tests and high-temperature tests
In UN-ECE/WP29, discussions are currently being held on whether to include lowtemperature tests and high-temperature tests in WLTP, in addition to the conventionalemission tests under the normal temperature. The test methods for low-temperature
tests will be established by 2021. As the low-temperature tests and high-temperature
tests are effective measures to reduce emissions in the actual use conditions of thevehicles in combination with the on-the-road inspections and the guidelines for safetycontrol described in Section 5.1.5, the Japanese government should also actively
participate in and contribute to the reviewing of international standards and discuss thenecessity of introducing those tests by conducting field surveys, etc.

5.1.7 Measures to reduce emissions from gasoline/LPG heavy-duty vehicles
At present, regarding gasoline- or LPG-fueled ordinary-sized and small-sized motor
vehicles with a gross vehicle weight exceeding 3.5 tons(excluding those exclusively
used for carrying passengers and having a riding capacity of 10 people or less)19

(hereinafter referred to as “current gasoline/LPG heavy-duty vehicles”), the allowablemaximum emission values specified by the Post New Long-Term Regulations (2009
Regulation) are applied to the emission values measured in the JE05 mode.
After the introduction of WLTC, as with the current gasoline/LPG heavy-duty
vehicles, JE05 mode rather than the current JC08 mode will be used for the emission
measurement of gasoline/LPG passenger cars (limited to those with a riding capacityof 10 people and a gross vehicle weight exceeding 3.5 tons). The allowable maximum
emission values specified by the Post New Long-Term Regulations (2009 Regulation)
will be applied to the emission values measured in the JE05 mode.
Regarding both of the above vehicle types (gasoline- or LPG-fueled ordinary-sized
and small-sized motor vehicles with a gross vehicle weight exceeding 3.5 tons
(excluding those exclusively used for carrying passengers and having a riding capacityof 9 people or less),hereinafter collectively referred to as “gasoline/LPG heavy-duty

vehicles”), it is necessary to consider introducing off-cycle emission measures and
OBD II as well as strengthening the emission regulations, including the introduction ofcold start tests as needed. For this consideration, the state of air pollution bygasoline/LPG heavy-duty vehicles, contribution of their emissions, and trends intechnological developments should be taken care of.

5.1.8 Measures to reduce emissions from special motor vehicles
As for special motor vehicles, the regulations applied to them differ according to therated output of an engine, so it is necessary to consider measures that will benecessary in the future according to each category.
(1) Special motor vehicles with a rated output of 19 kW or more but less than 560 kW
For special motor vehicles with a rated output of 19 kW or more but less than 560
kW, it is necessary to consider strengthening the emission regulation for them asnecessary, taking into account the state of air pollution, contribution of their emissions,
technological developments trends, and international trends.
Particularly with regard to measures to reduce fine particulate matter, it is necessary
to consider the required measures, including the PN regulations introduced for vehicles
20

other than special motor vehicles, as the contribution of special motor vehicles to PM
emissions is expected to increase.
(2) Special motor vehicles with a rated output of less than 19 kW and 560 kW or more
Special motor vehicles with a rated output of less than 19 kW and 560 kW or moreare currently not subject to any emission regulation. It is recommended that the
government consider the introduction of emission regulation for them as necessary,taking into account the state of air pollution, contribution of their emissions,
technological developments trends, international trends, the effects of the designation
system for construction machinery by emission type implemented by the MLIT, study
on emissions from general-purpose diesel engines below 19 kW voluntarily conductedby the Japan Land Engine Manufacturers Association, and so on.

5.1.9 Effect of fuel properties on emissions
In Japan, the oil demand peaked in 1999 and has been declining since then, due tothe declining population and various energy-saving efforts. In addition, SophisticatedMethods of Energy Supply Structures has been enforced to meet the decreasing
demand for heavy fuel oil A, B and C*43 and to use them for motor fuel. Given thissituation, the residue oil generated in the refining process at refineries (such as heavy
oil left over from the crude oil refining process) has been decomposed and mixed withgasoline or diesel for effective use. It has been pointed out that motor fuel mixed withdecomposed residue oil has an effect on fine particulate matter and PN in emissions,by the impact assessment of the use of decomposed motor fuel on vehicles, etc.
(JATOP III report: May 9, 2018) conducted by the Japan Petroleum Energy Center.
Biofuels effective in fighting global warming include, in addition to fuel mixed with up
to 10 volume% of bioethanol for gasoline vehicles, biodiesel fuels used by diesel
vehicles (diesel with content of 5.0 mass% or less of fatty acid methyl ester synthesizedfrom fats and oils of biomass). The use of these fuels must meet the quality stipulatedby the Act on the Quality Control of Gasoline and Other Fuels (Act No. 88 of 1976).
Diesel vehicles, in particular, are made for diesel as fuel, and given emission reduction
devices are more sophisticated than before, with the tightening of emission regulations.
21

Therefore, the use of bio-mixed diesel with content of more than 5.0 mass% of fatty
acid methyl ester may change the combustion characteristics of the engine, affect the
purification capacity of the emission reduction system and increase the amount ofemissions. In light of the above, the Ministry of Land, Infrastructure, Transport andTourism has established guidelines on points to note, etc. for fuels, modifications,inspection and maintenance in order to ensure the safety of diesel vehicles in using
such fuels in test and research, and has provided advice and warnings. Consequently,
when using such fuels, it is necessary to investigate the effect of fuel properties on
emissions and to consider measures based on the results.

5.1.10 Measures on other non-regulated substances
Among volatile organic compounds (hereinafter referred to as “VOC”) discharged
from motor vehicles, those subject to regulation are HC and hydrocarbons excluding
methane (CH4), (NMHC), but their effects on air quality vary depending on thehydrocarbon component. It is therefore desirable, regarding non-regulated hazardous
air pollutants*44 discharged from motor vehicles, to develop infrastructure to assess theamount of emissions from motor vehicles by developing measuring methods andimproving measuring accuracy and to take necessary measures based on informationcollected. In doing so, it is also necessary to assess the effects of engine technologies,
after-treatment technologies, and qualities of fuel and lube oil on the amount of toxic
air pollutants emitted from motor vehicles.
In discussing the policy for motor vehicle emission reduction, care should be taken
so as to prevent the increase of not only carbon dioxide (CO2), which is a greenhousegas, but also such other compounds as methane (CH4) and nitrous oxide (also known
as dinitrogen monoxide, N2O).

5.2 Leading the international harmonization of technical standards for motor vehicle
emission reduction
In promoting motor vehicle emission reduction, it is essential to take into account the
air environment in Japan and take measures adapted to real-world running conditions
22

of motor vehicles in Japan. On the other hand, as the globalization of the automobile
industry progresses, international harmonization of motor vehicle emission reduction
measures offers an effective means to reduce cost and time for development ofemission reduction technologies and to promote their wide implementation.
Therefore, in studying each of the issues to be considered described in Section 5.1,
it is desirable for the public and private sectors to continue to work together to promote
the international harmonization of technical standards so that Japan can take the leadin it, bearing in mind the globalization of the automobile industry and maintaining theworld's most stringent level of emission regulation.

5.3 Measures, etc. related to policy for motor vehicle emission reduction
5.3.1 Promoting a comprehensive policy for motor vehicle emission reduction(1) Measures taken under the Act on Special Measures for Total Emission Reductionof NOx and PM
Regarding the progress and future plans of measures established in accordancewith the Basic Policy for Areawide Total Pollutant Load Control under the Act
Concerning Special Measures for Total Emission Reduction of Nitrogen Oxides andParticulate Matter from Automobiles in Specified Areas (Act No. 70 of 1992,
hereinafter referred to as “Automobile NOx/PM Act”), the Comprehensive Policy on
Motor Vehicle Emissions Subcommittee summarized an interim review in the fiscal
year 2016. This review suggested the need to further promote effective actions, suchas individual measures that are highly effective in reducing emissions, promotion of
next-generation motor vehicles, action plans for eco-driving, facilitation of traffic flow,
and suppression of traffic demand. The review also suggested the need to narrow
down the regions, out of the specified areas designated by the Act, that require
implementation of measures to achieve the environmental targets by the fiscal year
2020 through the use of the numerical calculation technique, etc., and to consider andimplement necessary measures in these regions. It is essential that a comprehensive
policy for motor vehicle emission reduction will be promoted by taking effective
measures with the cooperation of related governmental bodies based on the review
23results and close observation of the situation.

(2) Encouraging regular check and maintenance and vehicle inspection
In the future, it is important to keep making vehicles in use maintain good
performance of their emission reduction devices, by encouraging users to practiceregular check and maintenance and have periodical inspection (safety inspection) as
prescribed in the Road Transport Vehicle Act (Act No. 185 of 1951) and by checking
the function of emission reduction devices and inspecting fuel quality in guidance andcontrol on the streets (street inspection).
Inspections using the OBD system, including inspections of exhaust emission control
devices, are scheduled to start in 2024 for new models manufactured after 2021. Since
the inspections are expected to contribute to maintaining good performance of theemission reduction devices, it is important to continue to specifically discuss theimplementation of the inspections.
Furthermore, it is desirable to urgently consider the introduction of random sampling
surveillance of vehicles in use, including the necessity of such surveillance, based oninternational trends in Europe, the United States and other countries.

(3) Promoting eco-friendly driving practiceEco-friendly driving practice, such as avoiding sudden acceleration/deceleration andidling stop (driving practice to reduce environmental burden) is effective not only forCO2 reduction but for emission reduction as well. Moreover, since vehicles with theidling stop function or other eco-driving support functions have been put to practicaluse, it is desirable to continue the promotion of action plans and measures to spreadeco-driving and related technologies in cooperation with relevant ministries andagencies and concerned bodies that comprise the Eco-Drive Promotion Liaison
Committee, etc.

5.3.2 Promotion of eco-friendly motor vehicles
To further improve air quality and fight global warming, it is important to promote eco24

friendly motor vehicles, such as next-generation motor vehicles and low-emission, fuelefficient vehicles. It is therefore desirable to promote measures to support eco-friendly
motor vehicles on an ongoing basis, such as tax benefits as well as subsidies at thetime of purchase.
In addition, reducing vehicle emissions is generally in conflict with improving fuelefficiency, for example, like the relationship between NOx reduction performance ofdiesel vehicles and fuel consumption performance. Accordingly, it is hoped that
automobile manufacturers will be promoted to develop these technologies at the sametime.
It goes without saying that Life Cycle Assessment (LCA) will have to be taken into
account in the future when considering environmental performance.

5.3.3 Assessing the state of air quality and forecasting the effects of improvement
With the enhancement of motor vehicles emission regulations and comprehensive
policy for motor vehicle emission reduction, it becomes more and more important toaccurately assess the effect of past measures and forecast the effects of measures tobe taken in the future for the formulation and implementation of new measures. In doingso, it is necessary to sort out and update the emission inventory of PM2.5, NOx, VOC,
etc. and clarify the mechanism of generation of PM2.5, photochemical oxidants, andother pollutants. It is therefore desirable to create a system to assess the effects ofvarious measures on improved air quality along the road, etc. at the sources ofemissions. Moreover, the reproducibility of long-term trends in numerical simulation
models for air quality has been confirmed, and improvements are being made to thestage of assessing the effects of measures to reduce NOx, VOC and others
substances on the reduction of photochemical oxidant concentrations, etc. andconsidering additional measures. Their further utilization and improvement are desired.
Also, in order to formulate effective environmental measures, it is desirable toconsider the possibility of utilizing vehicle information including location information
through information and communications technology.

25

5.3.4 Continuous assessment of the costs and effects of measures
When introducing a new emission reduction measure for motor vehicles, it isimportant to continuously assess the actual cost required for the measure as well as
the effects on emission reduction and air quality improvement so that the data can beutilized in discussing future measures.

5.3.5 Research system improvement and securing of human resources for motor
vehicle emission reduction
In discussing the policy for motor vehicle emission reduction such as the assessmentof trends in emission reduction technologies, international trends in emission
regulations, establishment of measuring methods for emissions, and examining theamount of time necessary for technological development, it is essential to utilize expert
knowledge, research results, and other data obtained from neutral research institutions.
Especially at these research institutions, it is desirable to develop sufficient testing
systems and secure human resources, including testing facilities that are appropriate
for the importance of measures for motor vehicles, which comprise the core industryof Japan.

5.4 Measures responding to changes in environment surrounding motor vehicles
It is recognized that the air quality in Japan has been steadily improving due to thepast measures to reduce motor vehicle emissions, and the air quality standards are
generally achieved, except for photochemical oxidant concentrations. On the other
hand, the environment surrounding motor vehicles is expected to continue to change
significantly due to the advancement of information and communications technology,
the proliferation of highly motorized vehicles, the advancement of automated driving,
car sharing, and MaaS*45, and the introduction of unconventional maximum speed limiton expressways in the infrastructure sector in connection with social trends such as
declining birthrate, aging population and the global decarbonization trend.
It is expected that automobile manufacturers will work on the development oftechnologies to reduce emissions and improve fuel efficiency as measures against air
26pollution and global warming, and maintain and develop the superiority of Japanesetechnologies in the global community, while responding to these major social changes.

27

Attached Figure 1

Normalized engine speed (%)
Normalized torque (%)

Exhaust pipe emission test cycle for gasoline/LPG special
motor vehicles

Engine speed

TorqueTime (s)LSI-NRTC (Large Spark Ignition engines Non-Road Transient Cycle)
TorqueTorqueEngine speed
Engine speed

Intermediate

Idle

Time (s)7M- RMC（7M Ramped-Modal Cycle）

28

Engine speed

Normalized torque (%)

Rated

Attached Figure 2

Exhaust pipe emission test cycle for passenger cars, etc.
● Test cycle (i)車速, km/h(km/h)
Vehiclespeed

120

Low-speed phase

Medium-speed phase100

Low-speed phase

(M1)

80
60
40
20
0
0

200

400

600

800
1000
時間 (s)
,s
Time

1200

1400

1600

1800

1600

1800

1600

1800

● Test cycle (ii)
車速, km/h(km/h)
Vehiclespeed

120

Low-speed phase

Medium-speed phase High-speed phase

100
80
60
40
20
0
0

200

400

600

800
1000
時間 (s)
,s
Time

1200

1400

● Test cycle (iii)120

車速, km/h(km/h)
Vehiclespeed

Low-speed phase

Medium-speed phase High-speed phase

100
80
60
40
20
0
0

200

400

600

800
1000
時間 (s)
,s
Time

29

1200

1400

● Test cycle (iv)
, km/hVehicle車速
speed(km/h)

120

Low-speed phase

Medium-speed phase High-speed phase

100
80
60
40
20
0
0

200

400

600

800
1000
時間 (s)
,s
Time

1200

1400

1600

1800

*Note: The test cycle is determined for each type of vehicle as follows:
Vehicle type

Test cycle

Vehicles with a PMR not exceeding 22 W/kg

Test cycle (i)Gasoline/LPG passenger
cars
Gasoline/LPG lightfreight vehicles
Gasoline/LPG light-

Vehicles with a PMR exceeding 22 W/kg but
not exceeding 34 W/kg

weight vehicles

Vehicles with a maximum

Gasoline/LPG medium-speed of less than 120

weight vehicles
Diesel passenger cars

Vehicles with a

Test cycle (ii)

Test cycle (iii)

km/h

PMR

Diesel light-weightexceeding

Vehicles with a maximum

vehicles34 W/kg

speed of 120 km/h or

Test cycle (iv)moreDiesel medium-weightvehiclesTest cycle (i): a test cycle applied to Class 1 vehicles in WTLP-gtr
Test cycle (ii): a test cycle applied to Class 2 vehicles in WTLP-gtr (excluding the extra-high-speed phase)
Test cycle (iii): a test cycle applied to Class 3a vehicles in WTLP-gtr (excluding the extra-high-speed phase)
Test cycle (iv): a test cycle applied to Class 3b vehicles in WTLP-gtr (excluding the extra-high-speed phase)30

Attached Table 1

Allowable Maximum Desired Values for Emissions from
Gasoline Direct Injection Vehicles
Allowable maximum desired value
Vehicle type (Note 1)(average)
PN

Gasoline/LPG passenger cars*29(Note 2)Gasoline/LPG
vehicles*30 (Note 3)
Gasoline/LPG
vehicles*31(Note 4)
Gasoline/LPG
vehicles*32 (Note 5)

light-freight
light-weight

6.0×1011 [particles/km]

medium-weight

Gasoline/LPG
vehicles*33 (Note 6)

heavy-duty

6.0×1011 [particles/kWh](Note １) Limited to vehicles equipped with in-cylinder direct injection gasoline engines(Note ２) Gasoline- or LPG-fueled ordinary-sized, small-sized, and light motor vehicles exclusively
used for carrying passengers and having a riding capacity of 10 people or less (excluding
those with a riding capacity of 10 people and a gross vehicle weight exceeding 3.5 tons, aswell as two-wheeled vehicles).
(Note ３) Gasoline- or LPG-fueled light motor vehicles (excluding those exclusively used for carrying
passengers, as well as two-wheeled vehicles)(Note ４) Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle
weight of 1.7 tons or less (excluding those exclusively used for carrying passengers andhaving a riding capacity of 10 people or less, as well as two-wheeled vehicles)(Note ５) Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle
weight exceeding 1.7 tons but not exceeding 3.5 tons (excluding those exclusively used forcarrying passengers and having a riding capacity of 10 people or less, as well as two-wheeledvehicles)(Note ６) Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle
weight exceeding 3.5 tons (excluding those exclusively used for carrying passengers andhaving a riding capacity of 9 people or less, as well as two-wheeled vehicles)31

Attached Table 2

Allowable Maximum Desired Values for Emissions from Diesel
VehiclesAllowable maximum desired value (average)
Vehicle type
PN

Diesel passenger cars (Note 1)
Diesel light-weight vehicles*34 (Note 2)
Diesel medium-weight vehicles*35 (Note 3)

6.0×1011 [particles/km]

6.0×1011 [particles/kWh] (limited to WHTC)

Diesel heavy-duty vehicles*36 (Note 4)
8.0×1011 [particles/kWh] (limited to WHSC)(Note 1) Diesel-fueled ordinary-sized and small-sized motor vehicles exclusively used for carrying
passengers and having a riding capacity of 10 people or less (excluding those with a riding
capacity of 10 people and a gross vehicle weight exceeding 3.5 tons, as well as two-wheeledvehicles)(Note 2) Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle weight of 1.7 tonsor less (excluding those exclusively used for carrying passengers and having a riding capacity of
10 people or less, as well as two-wheeled vehicles)(Note 3) Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle weight exceeding
1.7 tons but not exceeding 3.5 tons (excluding those exclusively used for carrying passengers andhaving a riding capacity of 10 people or less, as well as two-wheeled vehicles)(Note 4) Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle weight exceeding
3.5 tons (excluding those exclusively used for carrying passengers and having a riding capacity of
10 people or less, as well as two-wheeled vehicles)32

Attached Table 3

Allowable maximum desired values for exhaust pipe emissions
from gasoline/LPG special motor vehicles
Allowable maximum desired value (average)
Vehicle type

Gasoline/LPG special motor vehicles(Note 1)

CO

HC

NOx

15.0 g/kWh

0.6 g/kWh

0.3 g/kWh(Note 1) Limited to gasoline- or LPG-fueled special motor vehicles with a rated output of 19 kW or
more but less than 560 kW

33

Glossary*1Ordinary-sized motor vehicles

Defined in Article 2 of the Regulation for Enforcement of the Road Transport
Vehicle Act (Ministry of Transport Order No. 74 of 1951, hereinafter referred to as
the “Regulation”). Motor vehicles other than small-sized and light motor vehicles
and large-sized and small-sized special motor vehicles. Motorcycles are notincluded.

*2Small-sized motor vehicles

Defined in Article 2 of the Regulation. Motor vehicles of 4.70 m or less in length,1.70 m or less in width, and 2.00 m or less in height, other than light motor vehicles,
large-sized special motor vehicles, and small-sized special motor vehicles. (Incases of motor vehicles powered by an internal combustion engine (excluding
diesel-fueled motor vehicles and motor vehicles powered only by natural gas),
limited to those whose engine displacement is 2.00 l or less).

*3Light motor vehicles

Defined in Article 2 of the Regulation. Motor vehicles of 3.40 m or less in length,1.48 m or less in width, 2.00 m or less in height, and 0.660 l or less in engine
displacement, excluding large-sized special motor vehicles and small-sized special
motor vehicles.

*4Motorcycles

Two-wheeled small-sized motor vehicles and light motor vehicles (excluding thosewith an engine displacement of 0.125 l or less) as defined in Article 2 of theRegulation. Light motorcycles are defined as those of 2.50 m or less in length, 1.30
m or less in width, and 2.00 m or less in height, and 0.250 l or less in engine
displacement. All other motorcycles are classified as small-sized motorcycles.

34

*5Motor-driven cycles

Defined in Article 2, paragraph 3 of the Road Transport Vehicle Act, of which anengine displacement is specified in Article 1 of the Regulation. Among two-wheeledvehicles, those with an engine displacement of 0.125 l or less (0.050 l or less forall others). Of these vehicles, those with an engine displacement of 0.050 l or lessare classified as Class 1 motor-driven cycles and others are classified as Class 2
motor-driven cycles.

*6Special motor vehicles

Large-sized special motor vehicles and small-sized special motor vehicles definedin Article 2 of the Regulation. They include vehicles of special structure such as
bulldozers, forklifts, and agricultural tractors. Of these, small-sized special motor
vehicles are those of 4.70 m or less in length, 1.70 m or less in width, 2.80 m orless in height and a maximum speed of 15 km/h or less. (For some motor vehicles
including agricultural tractors, there is no limitation on size, but the maximum speed
is less than 35 km/h.)*7WMTC [Worldwide Motorcycle emissions Test Cycle]

Worldwide harmonized test cycles defined in the “Worldwide Harmonized
Motorcycle Emissions Certification Procedure”, which was established by UNECE/WP29 with the participation of Japan based on the “Agreement Concerning
the Establishing of Global Technical Regulations for Wheeled Vehicles, Equipment
and Parts which can be Fitted and/or be Used on Wheeled Vehicles” (hereinafterreferred to as “1998 Agreement”).

*8PM [Particulate Matter]

Abbreviated name for particulate matter. PM emitted from motor vehicles isdivided broadly into black smoke and sulfate, and SOF (Soluble Organic Fraction).

*9WLTP [Worldwide harmonized Light vehicles Test Procedure]

35

A worldwide harmonized test method for determining the levels of emissions andfuel consumption of passenger cars established by UN-ECE/WP29 with theparticipation of Japan based on the 1998 Agreement. In addition to the Worldwide
Light-duty Test Cycles (WLTC) for passenger cars and other vehicles, the WLTP
defines the cold start test, the weight of vehicles at the time of testing, etc.

*10WLTC [Worldwide Light-duty Test Cycle]

Worldwide harmonized test cycles specified in the International Worldwide
harmonized Light vehicles Test Procedure (WLTP) for passenger cars, etc.

*11WHDC [Worldwide harmonized Heavy Duty Certification]

A worldwide harmonized test method for determining the levels of emissions ofdiesel heavy-duty vehicles established by UN-ECE/WP29 with the participation ofJapan based on the 1998 Agreement. It defines these test cycles, Worldwide
Harmonized Transient Cycle (WHTC), Worldwide Harmonized Steady state Cycle(WHSC), etc.

*12WHTC [Worldwide Harmonized Transient Cycle]

A transient test cycle, as defined by the Worldwide harmonized Heavy Duty
Certification (WHDC) for diesel heavy-duty vehicles, that represents real world
driving.

*13WHSC [Worldwide Harmonized Steady state Cycle]

A steady-state cycle conducted under engine operating conditions equivalent tothose of WHTC, as defined by the Worldwide harmonized Heavy Duty Certification(WHDC) for diesel heavy-duty vehicles.

*14OCE [Off-Cycle Emission]

An emission reduction measure for conditions other than those prescribed by theworldwide harmonized official test cycles established by the UN-ECE/WP29 with36

the participation of Japan based on the 1998 Agreement. To verify the amount ofemissions in driving conditions other than the officially prescribed test cycles, it
defines additional emission tests based on WNTE (World Harmonized Not to
Exceed).

*15OBD system [On-Board Diagnostics System]

A kind of a self-diagnostic device, onboard failure diagnostic system that monitors
the engine for system anomaly. OBD systems are classified into two types: thosewhich monitor for disconnection or other failures and high-level OBD systems(OBD-II) which detect the performance degradation, etc., of emission reduction
devices with various sensors.

*16 OpacimeterA test instrument that projects light through emissions sampled from the exhaust
pipe and measures how much the emissions are contaminated by PM (lightabsorption coefficient [m-1]) from the permeability of emissions*17Diesel special motor vehicles

Diesel-fueled large-sized special motor vehicles and small-sized special motor
vehicles*18NRTC [Non-Road Transient Cycle]

A transient test cycle for emissions from the engines of diesel special motor
vehicles established by EU and the U.S. NRTC is defined as a transient test cyclein the worldwide standard for diesel non-road mobile machinery (NRMM)
established by UN-ECE/WP29 with the participation of Japan based on the 1998
Agreement.

*19NRMM [Non-Road Mobile Machinery]

A worldwide harmonized test method for determining the levels of emissions from37

diesel special motor vehicles established by UN-ECE/WP29 with the participationof Japan based on the 1998 Agreement. It defines the transient test cycle foremissions from the engines of diesel special motor vehicles (Non-Road Transient
Cycle, NRTC), etc.

*20Blow-by Gas

Mixed gas containing the combustion gas, which leaked into the crankcase throughpiston ring gaps, etc., mist of the lubricant in the crankcase, and air. Regulations
have been introduced for two-wheeled vehicles, passenger cars, heavy-duty
vehicles, and diesel special motor vehicles.

*21RMC [Ramped Modal Cycle]

One of the steady-state cycles defined in NRMM-gtr. As opposed to C1 mode
which first measures emissions at eight measuring points and then calculates theamount of emissions by obtaining the weighted average, RMC measuresemissions by continuously sampling them throughout the test cycle just like NRTC.

*22PM
2.5 [Particulate Matter 2.5]

Fine particulate matter suspended in the air, as sampled after a device removes
particles larger than 2.5 μm by 50%. As a whole, PM2.5 has certain influence on
respiratory diseases, circulatory diseases, lung cancer, etc.

*23Gasoline/LPG special motor vehicles

Gasoline- or LPG-fueled large-sized special motor vehicles and small-sized
special motor vehicles*24DPF [Diesel Particulate Filter]

A system to remove diesel fine particulate matter which collects PM in theemissions from motor vehicles through a filter installed in the exhaust system of
the engine and removes them with electric heating wires and catalysts. Those with38

catalysts are called continuous regeneration type DPF.

*25Diesel passenger cars

Diesel-fueled ordinary-sized and small-sized motor vehicles exclusively used forcarrying passengers and having a riding capacity of 10 people or less (excluding
those having a riding capacity of 10 and with a gross vehicle weight exceeding 3.5
tons, as well as two-wheeled vehicles)*26Pool fire

Liquid surface combustion which occurs when fuel injected into the cylinder at thetime of a cold start of an engine adheres to the wall and upper surface of the piston
as a liquid film and reacts with hot gas after combustion*27GPF [Gasoline Particulate Filter]

A gasoline particulate filter designed to trap and remove PM in emissions from a
direct injection gasoline engine*28JE05 mode

Abbreviated name for an engine-based emission test method introduced inconjunction with regulations based on the New Long-Term Targets. A test mode inwhich a representative driving mode based on the actual running conditions isdetermined by converting to engine speed and load depending on individual
engines. This conversion is calculated from the engine and vehicle specifications,as well as gear shift positions and transmissions, to reflect the engine speed andload used by the individual engines.

*29Gasoline/LPG passenger cars

Gasoline- or LPG-fueled ordinary-sized, small-sized, and light motor vehicles
exclusively used for carrying passengers and having a riding capacity of 10 people
or less (excluding those with a riding capacity of 10 people and a gross vehicle
39

weight exceeding 3.5 tons, as well as two-wheeled vehicles).

*30Gasoline/LPG light-freight vehicles

Gasoline- or LPG-fueled light motor vehicles (excluding those exclusively used forcarrying passengers, as well as two-wheeled vehicles)*31Gasoline/LPG light-weight vehicles

Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with agross vehicle weight of 1.7 tons or less (excluding those exclusively used forcarrying passengers and having a riding capacity of 10 people or less, as well as
two-wheeled vehicles)*32Gasoline/LPG medium-weight vehicles

Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with agross vehicle weight exceeding 1.7 tons but not exceeding 3.5 tons (excluding
those exclusively used for carrying passengers and having a riding capacity of 10
people or less, as well as two-wheeled vehicles)*33Gasoline/LPG heavy-duty vehicles

Gasoline- or LPG-fueled ordinary-sized and small-sized motor vehicles with agross vehicle weight exceeding 3.5 tons (excluding those exclusively used forcarrying passengers and having a riding capacity of 10 people or less, as well as
two-wheeled vehicles)*34Diesel light-weight vehicles

Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicleof 1.7 tons or less (excluding those exclusively used for carrying passengers andhaving a riding capacity of 10 people or less, as well as two-wheeled vehicles)*35Diesel medium-weight vehicles

40Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle
weight exceeding 1.7 tons but not exceeding 3.5 tons (excluding those exclusively
used for carrying passengers and having a riding capacity of 10 people or less, aswell as two-wheeled vehicles)*36Diesel heavy-duty vehicles

Diesel-fueled ordinary-sized and small-sized motor vehicles with a gross vehicle
weight exceeding 3.5 tons (excluding those exclusively used for carrying
passengers and having a riding capacity of 10 people or less, as well as twowheeled vehicles)*37LSI-NRTC [Large Spark Ignition engines Non-Road Transient Cycle]

Test cycle for gasoline/LPG special motor vehicles. It is used as a transient test
cycle for engines with an output of less than 56 kW in Europe and as a transient
test cycle for full power engines in the U.S.

*38JTC [Japan Transient Cycle]

A transient cycle for investigation based on the measurement patterns shown inAnnex A.5 “Fuel consumption of engine vehicles” of JIS D6202-2011 “Forklift
trucks - Standard form of specification” selected as a cycle that simulates the actual
operations of forklift trucks, which account for almost all of gasoline/LPG special
motor vehicles used in Japan.

*39Output ratio

The ratio of average power when defining as average power the average value ofthe products per second of engine speed and torque normalized to the rated
value*40Unladen state (running order)

Unoccupied and unladen state fully loaded with fuel, coolant, and lubricant, and41

equipped with all tools and accessories (including a spare tire) specified byautomobile manufacturers as standard equipment. In this case, loading the fullvolume of fuel means loading 90% or more of the total fuel capacity of the fuelsystem. This is different from the “vehicle weight.”*41Round-robin tests

A test for examining the reliability, etc. of a measuring method or measurement
equipment conducted by assigning the same vehicles and measurement
equipment to multiple testing institutions*42Canister

A container filled with activated carbon that is installed in gasoline vehicles tosuppress fuel evaporative emissions. Fuel evaporative emissions that fill the fueltank are adsorbed into activated carbon, and are desorbed by letting a portion of
air supplied to the engine pass through while the vehicle is running, and then areburned in the engine.

*43Heavy fuel oil

Distillation residue or mixture of distillation residue and diesel fraction, made into
a product by adjusting viscosity, residual carbon, sulfur content, or pour point,
according to its use. According to kinematic viscosity, it is roughly classified into
three: heavy fuel oil A, B, and C.

*44Hazardous air pollutants

Hazardous air pollutants are defined in Article 2, paragraph 15, of the Air Pollution
Control Act as “a substance that is likely to harm human health if it is ingested
continuously and that causes air pollution.” The Future Policy on Hazardous Air
Pollutants (Second Report) (compiled by the Central Environment Council in
October 1996) listed 234 substances as those which were likely to be hazardous
air pollutants and designated 22 of them as top priority substances that were highly42harmful for human health. Later, the Ninth Report (compiled by the Central
Environment Council in October 2010) reviewed them to 248 substances and 23
substances, respectively.

*45MaaS [Mobility as a Service]

The integration of various forms of transportation services into a single mobility
service accessible on demand

Reference: Society of Automotive Engineers of Japan, Japanese-English
Dictionary of Automotive Terms, etc.

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