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Emission Standards » Japan

Cars and Light Trucks

Passenger Cars

Two types of standards can be established in Japan, denoted as “mean” and “max” (the “max” standards are shown in brackets in the following tables). The “mean” standards are to be met as a type approval limit and as a production average. The “max” standards are to be met generally as an individual limit in series production and as type approval limit if sales are less than 2000 per vehicle model per year.

Emission standards for new diesel powered cars are listed in Table 1. The implementation dates refer to new vehicle models. Some of the standards allow a delay of up to one year for current production models.

Table 1
Japanese emission standards for diesel passenger cars, g/km
Vehicle WeightDateTestCOHCNOxPM
mean (max)mean (max)mean (max)mean (max)
< 1250 kg* 198610-15 mode 2.1 (2.7)0.40 (0.62) 0.70 (0.98) 
1990 2.1 (2.7)0.40 (0.62) 0.50 (0.72) 
1994 2.1 (2.7)0.40 (0.62) 0.50 (0.72)0.20 (0.34)
1997 2.1 (2.7)0.40 (0.62) 0.40 (0.55)0.08 (0.14)
2002a0.63 0.12 0.28 0.052
2005bJC08c 0.63 0.024d0.14 0.013
2009 0.63 0.024d0.08 0.005
2018WLTP 0.63 0.024d0.15 0.005
> 1250 kg* 198610-15 mode 2.1 (2.7)0.40 (0.62)0.90 (1.26) 
1992 2.1 (2.7)0.40 (0.62)0.60 (0.84) 
1994 2.1 (2.7)0.40 (0.62)0.60 (0.84)0.20 (0.34)
1998 2.1 (2.7)0.40 (0.62)0.40 (0.55)0.08 (0.14)
2002a0.63 0.12 0.30 0.056
2005bJC08c 0.63 0.024d0.15 0.014
2009e 0.63 0.024d0.08 0.005
2018WLTP 0.63 0.024d0.15 0.005
* - equivalent inertia weight (EIW); vehicle weight of 1265 kg
a - 2002.10 for domestic cars, 2004.09 for imports
b - full implementation by the end of 2005
c - full phase-in by 2011
d - non-methane hydrocarbons
e - 2009.10 for new domestic models; 2010.09 for existing models & imports

Table 2 lists emission standards for 2009 and later gasoline and LPG passenger cars.

Table 2
Japanese emission standards for gasoline and LPG passenger cars, g/km
DateTestCONMHCNOxPM
meanmeanmeanmean
2009JC08 1.150.050.050.005
2018WLTP 1.150.100.050.005
a - PM values apply only to direct-injection, lean-burn vehicles equipped with absorption-type NOx reduction catalysts

The test procedures have been changed on a number of occasions. The old 10-mode cycle was replaced by the 10-15 mode test effective 1991.11 for domestic cars and 1993.04 for imports. The 2005 regulation introduced the JC08 mode cycle which became fully phased-in by 2011 (vehicles were tested using 50 ppm S fuel for the 2005 standards). From 2018, emissions are tested over the WLTP test cycle.

Light Commercial Vehicles

Emission standards for new diesel fueled commercial vehicles are summarized in Table 3, and for those fueled by gasoline and LPG in Table 4.

Table 3
Emission standards for diesel light commercial vehicles
GVW ≤ 3500 kg (≤ 2500 kg before 2005)
Vehicle Weight*DateTestUnitCOHCNOxPM
mean (max)mean (max)mean (max)mean (max)
≤ 1700 kg 198810-15 modeg/km 2.1 (2.7)0.40 (0.62)0.90 (1.26) 
1993 2.1 (2.7)0.40 (0.62)0.60 (0.84)0.20 (0.34)
1997 2.1 (2.7)0.40 (0.62)0.40 (0.55)0.08 (0.14)
2002 0.63 0.12 0.28 0.052
2005bJC08c 0.63 0.024d0.140.013
2009 0.63 0.024d0.080.005
2018WLTP 0.63 0.024d0.150.005
> 1700 kg 19886 modeppm 790 (980)510 (670)DI: 380 (500)
IDI: 260 (350)
 
199310-15 modeg/km 2.1 (2.7)0.40 (0.62)1.30 (1.82)0.25 (0.43)
1997a2.1 (2.7)0.40 (0.62)0.70 (0.97)0.09 (0.18)
2003 0.63 0.12 0.49 0.06
2005bJC08c 0.63 0.024d0.250.015
2009e 0.63 0.024d0.150.007
2019WLTP 0.63 0.024d0.240.007
* - gross vehicle weight (GVW)
a - 1997: manual transmission vehicles; 1998: automatic transmission vehicles
b - full implementation by the end of 2005
c - full phase-in by 2011
d - non-methane hydrocarbons
e - 2009.10 for new domestic models; 2010.09 for existing models & imports
Table 4
Emission standards for gasoline and LPG light commercial vehicles, g/km
GVW ≤ 3500 kg
Vehicle WeightDateTestCONMHCNOxPM
meanmeanmeanmean
Mini 2009JC08 4.020.050.050.005a
2019WLTP 4.020.100.050.005a
≤ 1700 kg 2009JC08 1.150.050.050.005a
2019WLTP 1.150.100.050.005a
> 1700 kg 2009JC08 2.550.050.070.007a
2019WLTP 2.550.150.070.007a
a - PM values apply only to direct-injection, lean-burn vehicles equipped with absorption-type NOx reduction catalysts.