Future Policy forMotor Vehicle Emission Reduction(Eleventh Report)

August 10,2012
Central Environment Council

Chukanshin No. 668
August 10, 2012
To:

His Excellency Goshi Hosono
Minister of the Environment

From: Motoyuki Suzuki
Chairperson
Central Environment Council
In response to Inquiry No. 31 of May 21, 1996, on “Future Policy for Motor Vehicle Emission
Reduction”, the Central Environment Council has successively made reports starting from theinterim report (Chukanshin No. 83 of October 18, 1996) to the 10th report (Chukanshin No.
563 of July 28, 2010).
Of these reports, the 10th report cites, as future tasks, those related to the rethinking of theexhaust emission testing cycles, etc. of motorcycles and motor-driven cycles (hereinaftercollectively referred to as “two-wheeled vehicles”), and the introduction of nitrogen oxide(NOx) after-treatment devices. Further, after the 10th report, such new issues arose asmeasures to be taken to reduce emissions in so-called off-cycles, or running conditions otherthan officially prescribed testing mode, of diesel heavy-duty vehicles and the review of blacksmoke regulation for non-road mobile machinery. For this purpose, the Expert Committee on
Motor Vehicle Emissions discussed measures to reduce emissions from two-wheeled vehicles,
diesel heavy-duty vehicles, and diesel non-road mobile machinery. In discussing measures toreduce emissions from two-wheeled vehicles and diesel non-road mobile machinery, theCommittee paid special attention to reducing emissions in a way adapted to the real-world
status of air quality in Japan, harmonizing these measures with international regulations, andenhancing the competition of the automobile-related industries in Japan.
The results of the discussion were compiled in the Eleventh Report by the Expert Committee
on Motor Vehicle Emissions, as attached. The Air Environment Committee discussed thisEleventh Report and concluded that, in order to adequately promote the future policy for
motor vehicle emission reduction, it is appropriate to adopt the Eleventh Report and reduce
motor vehicle emissions as proposed therein.
The Council thus makes the following report:
1. Measures to Reduce Emissions from Two-Wheeled Vehicles
The achievement of the environmental standards on photochemical oxidants still remains at avery low level. Considering that two-wheeled vehicles discharge more emissions
inparticular hydrocarbons (HC) that contribute to the production of photochemical oxidants than gasoline and LPG-powered motor vehicles in terms of distance traveled per vehicle, it
is recommended to promote the emission reduction measures described in 1.1 to 1.3 below.
These measures should be applied also to two-wheeled vehicles fueled with 10-volume
percent bioethanol-blended gasoline.
1.1 Measures to reduce exhaust-pipe emissions

With regard to emission test cycles, it is recommended that, in place of the emission test
cycles (two-wheeled vehicle mode) currently used, the Worldwide harmonized Motorcycle
emission Test Cycle (WMTC), which was developed, with participation of Japan, at World
Forum for Harmonization of Vehicle Regulations of the United Nations Economic
Commission for Europe (UN-ECE/WP.29) be adopted.
The next-phase permissible limit target levels should be as indicated in Appendix and
implemented by the end of 2016. Pending the implementation of the next-phase permissible
limit target levels, the WMTC target levels shown in Appendix should be deemed equivalent
to the target levels for the two-wheeled vehicle mode currently in force.
1.2 Measures to reduce fuel-evaporative emissions
It is recommended that measures to reduce fuel-evaporative emissions from two-wheeledvehicles be introduced. As methods to test fuel-evaporative emissions, the diurnal breathing
loss test and the hot soak loss test similar to those used in the California State Test should beused. The permissible limit target level should be 2.0 g/test, which is equivalent to gasoline
and LPG motor vehicles, and should be implemented by the end of 2016.
1.3 Introduction of OBD systems
It should be made mandatory that two-wheeled vehicles be equipped with onboard diagnostic(OBD) systems that monitor electrical systems for disconnection or other failures. The
requirement should be implemented by the end of 2016.
1.4 Issues to be addressed in the future
Further reduction of emissions requires resolving technical problems that remain unsolved
and further technical development in the future. In discussing this task, it is recommended thatthe government make good use of the findings from field surveys, etc. at UN-ECE/WP.29 andcontribute to the development and review of international regulations, while considering
harmonization with international regulations developed at UN-ECE/WP.29.
2. Measures to Reduce Emissions from Diesel Heavy-Duty Vehicles
2.1 Measures to ensure the durability and reliability of NOx after-treatment devices
It was confirmed that motor vehicles in use compliant with the New Long-Term Targets
equipped with urea SCR (Selective Catalytic Reduction) systems emitted NOx exceeding
regulatory limits. A urea SCR system is made of a pre-stage oxidation catalyst, an SCRcatalyst, and a post-stage oxidation catalyst. Possible causes for the above-mentioned excess
include the poisoning of the catalysts of the urea SCR system by HC, sulfur, phosphorus, orother metals from unburned fuel or the deterioration of catalyst performance.
To solve the problem of HC poisoning of catalysts, it is desirable to consider implementing
such measures as regular heating of the urea SCR systems in in-use vehicles.
For the degradation of oxidation capacity in the pre-stage oxidation catalyst, causes other thanHC poisoning are also suspected but haven't been identified yet. Hence, before discussing
measures to prevent the performance degradation, further investigation should be made on its
causes, such as running patterns that may cause performance degradation.

Further, considering that urea SCR systems were found to lower their performance at distancetraveled less than durability distance, the current method for testing durability distance should
be reviewed to consider conditions less favorable to urea SCR systems as experienced in realworld.
2.2 Measures to reduce off-cycle emissions
The users of diesel heavy-duty vehicles for longer distance transportation value fuelefficiency. Since fuel-efficiency and the amount of NOx emission trade off each other, somevehicles may choose to increase emissions in real world, while keeping emissions within
regulatory limits in official test mode by electronically controlling the engine and improving
fuel efficiency under running conditions other than official testing modes, including realworld running.
It is therefore recommended that the government define engine controls that deteriorate
emissions from diesel heavy-duty vehicles as defeat strategies and prohibit their application,
while making it clear that controls necessary only to protect engines, etc. and ensure vehicle
safety as well as controls necessary only for starting and warming up the engine are notregarded as defeat strategies. For controls not regarded as defeat strategies, it is recommended
that conditions under which their protection is permitted as well as requirements for enablingand disabling protection be clearly defined and, further, that their use of these controls be
limited solely to cases where they are necessary to protect the engine even when they arewithin the limits of these requirements.
In determining whether or not a defeat strategy is used, it is appropriate to consider that thevehicle is in compliance when the fuel-efficiency actually measured at the emission test does
not show a gap of more than 3% from the fuel efficiency estimated by simulation and theamount of emissions doesn’t exceed the permissible target level (average) and, otherwise,
regard that the vehicle uses a defeat strategy.
Further, considering that the amount of emissions significantly varies even from the sameengine depending on how temperature changes with the position of the after-treatment device,
it is desirable to use, in the engine bench test, conditions less favorable to the after-treatment
device as experienced in real-world.
3. Measures to Reduce Emissions from Diesel Non-Road Mobile Machinery
3.1 Review of black smoke regulations
The results of the C1-mode black smoke test on diesel non-road mobile machinery compliant
with the 2011 Regulation showed that their black smoke pollution level dropped to 0% thanks
to DPF and other measures taken to reduce black smoke emissions. We assume that the blacksmoke pollution level will be kept at 0% still after reaching the 2014 Target levels. It istherefore recommended that the C1 mode black smoke test be abolished from the standpointof rationalizing the regulatory procedures.
Further, it is recommended that the method of measuring particulate matter (PM) emissions
from vehicles in use be changed from the current method using a black smoke pollution level
meter to the one using an opacimeter, and that the permissible limit target level for vehicles inuse be set at a light absorption coefficient of 0.5 m-1. The permissible limit target levels
measured with an opacimeter should be implemented from vehicles compliant with the 2014
Targets, provided, however, that, for vehicles with rated outputs of 19 kW or more up to 56

kW that maintain the permissible limit targets of 2014 from the 2011 Regulation, they shouldbe implemented by the end of 2016.
3.2 Additional emission reduction measures for harmonization with international regulations
The worldwide harmonized regulations on the method of measuring emissions from non-road
mobile machinery (NRMM) developed by UN-ECE/WP.29 in 2009 include additional
measures on blow-by gas and steady-state tests.
Blow-by gas may increase as the vehicle is used and engine parts wear over time. Prohibiting
diesel non-road mobile machinery from releasing the gas into the air may cause, when it
works on steep sites and gets overturned, the engine oil to flow into the air intake side and theengine to run away. It is therefore recommended that, while maintaining the prohibition of
blow-by gas emission in principle, vehicles that need to release blow-by gas in the air bemeasured not only for emissions but also for blow-by gas released in the air at the emission
test, and that a permissible limit target level be set on the total amount of the two emissions.
The NRMM requires that steady-state performance be evaluated either in C1 steady-state
cycle or in RMC (Ramped Modal Cycle). Considering that the amounts of emissions in C1and RMC cycles are the same, it is recommended to introduce RMC as a steady-state test
cycle and let the manufacturer choose either C1 or RMC at the emission test in type approval.
The additional blow-by gas measure and steady-state test should be implemented starting withvehicles compliant with 2014 targets. For vehicles of a rated output of 19 kW up to 56 kW,they should be implemented by the end of 2016.
4. Issues to be Addressed in the Future, etc.
The Expert Committee on Motor Vehicle Emissions will continue studying issues to beaddressed in the future as listed in the Eleventh Report. Among others, the Committee willplace special importance on the issues 4.1 to 4.4 discussed below. In studying these issues, it
is desirable to control emissions in a way adapted to real-world running practice in Japanconsidering the state of air quality of the country, join activities at UN-ECE/WP.29 forharmonization of international regulations, and best harmonize domestic measures withinternational regulations, taking into account the stage and schedule of discussions.
Furthermore, the Japanese Government should promote the measures proposed in the report,
including those in 4.5.
4.1 Measures to reduce emissions from passenger cars, etc.
For motor vehicles running on gasoline, LPG, and diesel other than heavy-duty vehicles, UNECE/WP.29, with the participating of Japan, has been discussing a WLTP (Worldwideharmonized Light vehicles Test Procedure) including WLTC (Worldwide harmonized Light
duty driving Test Cycle). It is recommended that the government continue actively taking partin the discussion and review, as the discussion progresses, the current test cycle (JC08 mode)and consider introducing WLTC. Further, it is recommended that, in the future, newpermissible limit targets for emissions be set as necessary in view of the state of air pollution,passenger cars’ contribution to emissions, technical developments, etc., while ensuring
compatibility between low fuel-consumption technologies and emission reduction
technologies.
4.2 Measures on fine particulate matters and black carbon

Japan introduced environmental standards on PM2.5 in September 2009 and has since beendeveloping a nationwide system for measurement of PM2.5. Meanwhile, Europe introduced aregulation in 2011 that focused on the number of PM particles emitted from motor vehicles
and plans to implement the regulation for diesel heavy-duty vehicles by the end of 2012.
However, the current method of counting the number of PM particles has a problem that it
cannot measure highly-volatile particles, which are supposed to largely contribute to PM2.5
concentration. Furthermore, black carbon, which is generated when fossil fuels burn, not only
pollutes the air, but accelerates global warming as well, and has become the subject ofinternational discussion on its actual effects and necessity of reduction. Although the blackcarbon is responsible for a large part of PM discharged from motor vehicles, we assume thatmost of it is collected before emission, now that diesel vehicles and diesel non-road mobilemachinery compliant with the latest regulations on emissions are equipped with DPFs.
It is therefore recommended that the government continue faithfully implementing the PM
reduction measures so far introduced, such as regulations on emissions, and, in the future,
study a comprehensive policy on PM2.5, the effects of black carbons on global warming andmeasures to reduce the emission, and measures to be taken specifically for motor vehicles.
4.3 Measures on other non-regulated substances
As to measures on volatile organic compounds (VOC) discharged from motor vehicles,hydrocarbons and non-methane hydrocarbons (NMHC) are currently being regulated, but
VOCs’ effect on air pollution varies from a hydrocarbon to another. It is therefore
recommended that the government study necessary measures based on information so far
obtained through the development of measuring methods, improvement of measurement
accuracy, and improvement of the infrastructure to measure the amount of emissions ofunregulated, hazardous air pollutants from motor vehicles.
Furthermore, when, in the future, it becomes necessary to study a comprehensive policy for
VOC reduction, including regulations on plants and offices, it is recommended that thegovernment, as part of such a task, study anew measures to reduce emissions from motorvehicles and fuel standards, including their effects and future tasks.
4.4 Effects of Bio-Diesel Fuels on Emissions
Bio-diesel fuels are effective to mitigate global warming. The use of fatty acid methyl ester(FAME), among others, has been particularly popular in recent years especially in certain
regions. On the other hand, on diesel vehicles, which have been so far designed for diesel oil
and now provided with very sophisticated emission reduction technologies to meetincreasingly stringent emission standards, the use of bio-diesel fuels may affect theiremissions. It is therefore recommended that study be made on the effects of the use of biodiesel fuels on diesel vehicles compliant with Post New Long-Term Targets and on measures
to be taken based on the results of the study.
4.5 Encouragement of regular check and maintenance, and periodical vehicle inspection
It is important to continue taking necessary measures to ensure that in-use motor vehicles
keep their emission reduction performance, by encouraging users to practice regular checkand maintenance as well as periodical vehicle inspection prescribed in the Road Trucking Act(vehicle inspection) and by helping them check the function of emission reduction devices
and check fuel quality through activities for guidance and control on streets (street inspection),

Attached Table
Permissible Limit Target Levels for Exhaust Pipe Emissions from
Two-Wheeled Vehicles for 2016

Next-phasetarget levels(average)

CarbonHydrocarbons
monoxides

Nitrogenoxides

Two-wheeled vehicles of atotal emission of more than
0.05o l but less than 0.150 l
and a maximum speed of 50km/h or less or two-wheeledvehicles of a total emission ofless than 0.150 l and amaximum speed of more than
50 km/h but less than 100 km/h
(Class 1)

1.14g/km

0.30g/km

0.07g/km

Two-wheeled vehicles of a
total emission of less than
0.150 l and a maximum speedof 100 km/h or more but lessthan 130 km/h, or a total
emission 0.150 l or more and amaximum speed of less than
130 km/h (Class 2)

1.14g/km0.20g/km

0.07g/km

Two-wheeled vehicles of a
maximum speed of 130 km/h
or more (Class 3)

1.14g/km

0.17g/km

0.09g/km

2.2g/km0.45g/km

0.16g/km

2.62g/km

0.27g/km

0.21g/km

Current
Motor-driven cycles
equivalentMotorcycles
regulatory levels(Average)