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Emission Standards

India: Heavy-Duty Truck and Bus Engines

Emission Standards

Emission standards for new heavy-duty onroad engines—applicable to vehicles of GVW > 3,500 kg—are listed in Table 1. Limits for BS V shown in Table 1 were proposed in November 2015 [3297][3298] but later removed from an updated proposal [3349]; transitioning the nation directly to BS VI from BS IV.

Table 1
Emission standards for hevy-duty engines
StageYearTestCOHCCH4NOxPMPNNH3
g/kWhkWh-1ppm
1992ECE R4917.32.7--
1996ECE R4911.22.414.4-
India 20002000ECE R494.51.18.00.36a
BS II2005†ECE R494.01.17.00.15
BS III2010†ESC2.10.665.00.10
ETC5.450.785.00.16
BS IV2010‡ESC1.50.463.50.02
ETC4.00.553.50.03
BS Vn/a bESC1.50.462.00.02
ETC4.00.551.1d2.00.03
BS VI2020cWHSC (CI) 1.50.13 0.400.018.0×101110
WHTC (CI) 4.00.16 0.460.016.0×1011e10
WHTC (PI) 4.00.16f0.50 0.460.016.0×1011e10
† earlier introduction in selected regions, see India: Table 1
‡ only in selected regions, see India: Table 1
a 0.612 for engines below 85 kW
b Initially proposed in 2015.11 [3297][3298] but removed from a 2016.02 proposal [3349]
c Proposed schedule and limits
d For CNG engines only
e Applicable from April 1, 2025 for new models and April 1, 2026 for existing models
f NMHC

Stage VI (Euro VI) gasoline engines are certified with E10 and diesel engines with B7. In-use compliance test procedures for BS VI engines are defined in an Automotive Industry Standard (AIS-137) to be published by the Automotive Research Association of India. The maximum in-use conformity factor for CO, THC, NMHC, CH4 and NOx is 1.50. A PEMS test at type approval for vehicles with BS VI engines is also required. Off-cycle limits following the WNTE cycle must also be met.

In November 2015, a draft proposal was published that required vehicles compatible with biodiesel blends up to B100 to certify with both diesel fuel and B100 (see India: Table 2).

OBD Requirements

Proposed OBD requirements are similar to those for Europe. Table 2 summarizes the phase-in schedule [3298].

Table 2
OBD threshold limits (OTL)
StageYearVahicle CategoryNOxCOPM
g/kWh
BS Vn/a aAll7.00.1d
BS VI2020b CI engines 1.5Performance monitoring
Gas engines† 1.5-
BS VI2026c CI engines 1.20.025e
Gas engines† 1.27.5e-
a Initially proposed in 2015.11 [3297][3298] but removed from a 2016.02 proposal [3349]
b For new models, 2021 for existing models
d CI engines only
e Limit to be reviewed at a later date
† All gas fueled engines and PI engines fitted to vehicles category M3, to N2 vehicles having a maximum permissible mass > 7.5 tonnes, and to N3 vehicles

More details on Euro I-VI regulations and testing requirements can be found in the EU heavy-duty engine standards page.