2. In the Central Motor Vehicles Rules, 1989, (hereinafter referred to as the said rules), in rule 115, in sub-rule (18),-
(I) in clause (i), in Table 2,-
(a) in notes (4),-
(i) in clause (a), for the brackets, letters, figures and word “(G20, G23 and G25)”, the brackets, letter and figures “(G20)” shall be substituted;
(ii) in clause (b),
(A) for the letters and figures “BIS 15958:2012”, the letters and figures “BIS 15958:2023” shall be substituted;
(B) for the letters and figures “BIS 14861:2000”, the letters and figures “BIS 14861:2020” shall be substituted;
(iii) in clause (f), the letters and figures “IS 16087:2013”, the letters and figures “IS 16087:2025” shall be substituted;
(iv) clause (i) shall be omitted.
(b) in notes 9,-
(A) in clause (ii),-
(i) for the letters and figures “BIS 15958:2012”, the letters and figures “BIS 15958:2023” shall be substituted;
(ii) for the letters and figures “BIS 14681:2000”, the letters and figures “BIS 14861:2020” shall be substituted;
(B) in clause (iii), for the letters and figures “IS 15607”, the letters and figures “IS 15607:2022” shall be substituted;
(C) in clause (v), for the letters and figures “IS 16634:2017”, the letters and figures “IS 16634:2023” shall be substituted;
(D) in clause (vi), for the letters and figures “IS 16087:2013”, the letters and figures “IS 16087:2025” shall be substituted;
(E) in clause (viii), after the letters and figures “IS 17021:2018”, the words and letters “and as amended from time to time by BIS” shall be inserted;
(II) after clause (i-A), the following clause shall be inserted, namely: - “(i-B) The Emission Standards for Bharat Stage VI (BS-VI) with Worldwide Harmonised Light Duty Test Procedure (WLTP) test cycle (for N1 category): The emission standards for vehicles of category N1, manufactured on or after the 01st April, 2028, for all models, shall be as under:
TABLE 1 Exhaust Emission Limits for Vehicles Fitted with PI and CI Internal Combustion Engines
| Sr. No. | Category | Class | Reference Mass (RM)(2) (kg) | Mass of carbon mon oxide (CO) | Mass of total hydro carbons (THC) | Mass of nonmethane hydrocarbons (NMHC) | Mass of oxides of nitrogen (NOx) | Combined mass of total hydrocarbons and oxides of nitrogen (THC + NOx) | Mass of particulate matter (PM) | Number of particles (PN) | |||||||
| L1 (mg/km) | L2 (mg/km) | L3 (mg/km) | L4 (mg/km) | L2 + L4 (mg/km) | L5 (mg/km) | L6 (#/km) | |||||||||||
| PI | CI | PI | CI | PI | CI | PI | CI | PI | CI | PI (1) | CI | PI (1) | CI | ||||
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) | (14) | (15) | (16) | (17) | (18) |
| 1. | N1 | I | RM ≤ 1305 | 1000 | 500 | 100 | - | 68 | 60 | 80 | - | 170 | 4.5 | 4.5 | 6 × 1011 | 6 × 1011 | |
| 2. | II | 1305 < RM ≤ 1760 | 1810 | 630 | 130 | - | 90 | - | 75 | 105 | - | 195 | 4.5 | 4.5 | 6 × 1011 | 6 × 1011 | |
| 3. | III | 1760 < RM | 2270 | 740 | 160 | - | 108 | - | 82 | 125 | - | 215 | 4.5 | 4.5 | 6 × 1011 | 6 × 1011 | |
Explanation 1.- PI = Positive Ignition, CI = Compression Ignition
(a) For Positive Ignition, Particulate mass and number of particles limit shall apply only to vehicles with Direct Injection Engines.
(b) "Reference mass" means the vehicle’s mass in running order plus 75 kg.
Explanation 2.- For vehicles of category N2 between 3.5 and 5.0 tonnes Gross Vehicle Weight, originating from a type of vehicle of category N1, the approval authority may grant an emission type-approval if the N2 vehicle meets the emission requirements for a type of vehicle of category N1. Such N2 vehicles shall be required to meet COP/ISC/IUPR requirements under this rule.
Explanation 3.- Application of Test Requirements for Type-Approval – BS VI, with WLTP test procedures, shall be the same as that of Table 2 of clause (i) if sub-rule (18) of rule 115, including Explanatory Note (1) to (5) only. Notes. -
1. The test shall be on a Chassis Dynamometer.
2. The test procedure, including driving cycle, shall be as provided in AIS-175, as amended from time to time.
3. There shall be no relaxation of norms for Conformity of Production (COP) purposes, and the procedure for compliance shall be as per AIS-175, as amended from time to time.
4. Specifications for Reference Fuels shall be same as that of Note 4 of clause (i) of sub-rule (18) of rule 115.
5. Crankcase ventilation system shall not permit the emission of any of the crankcase gases into the atmosphere.
6. Evaporative emission shall not be more than 2.0 g/test from gasoline-fuelled vehicles. The evaporative emission test procedure for gasoline-fuelled vehicles shall be as per the procedure specified in AIS 175, and as amended from time to time.
7. The conformity of production (CoP) testing procedure shall be as described in AIS-137.
8. Conformity of production (CoP) frequency and samples shall be same as that of Notes 8 of
Table 2 of clause (i) of sub-rule (18) of rule 115.
9. Specifications for Commercial Fuels shall be same as that of Notes 9 of Table 2 of clause (i) of sub-rule (18) of rule 115.
10. Specifications of NOx reduction agent AUS 32 (Aqueous Urea Solution) shall be same as that of Notes 10 of Table 2 of clause (i) of sub-rule (18) of rule 115.
11. For Diesel vehicles, the requirements for the emission of visible pollutants (smoke) shall be same as that of Notes 11 of Table 2 of clause (i) of sub-rule (18) of rule 115.
12. The engine power shall be measured on engine dynamometer and the procedure and requirements for the measured power shall conform to AIS 137, as amended from time to time.
13. Type II Test: Vehicles fitted with PI engines specified in this sub-clause shall comply with the provisions of clause (i) of sub-rule (2) of rule 115 as applicable.
14. Free Acceleration Smoke: Vehicles fitted with CI engines specified in this sub-clause shall comply with the provisions of clause (ii) of sub-rule (2) of rule 115 as applicable.
15. Deterioration Factor shall be as given in the following Table, namely: -
Table 2 Deterioration Factor: BS VI – WLTP Test Cycle
| Sl. No. | Engine Category | Assigned Deterioration Factor | ||||||
| CO | THC | NMHC | NOx | HC+NOx | Particulate Matter (PM) | Particle Number (PN) | ||
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) |
| 1. | Positive Ignition | 1.5 | 1.3 | 1.3 | 1.6 | - | 1.0 | 1.0 |
| 2. | Compression Ignition | 1.5 | - | - | 1.1 | 1.1 | 1.0 | 1.0 |
(i) Alternatively, the vehicle manufacturer may opt for a vehicle ageing test of 1,60,000 km or a bench ageing durability test, for evaluating the Deterioration factor as per AIS 175 and as amended from time to time,
(ii) This test may be performed by driving vehicle on a test track, on the road, or on a chassis dynamometer or Engine Test Bench as per AIS 175 and as amended from time to time
(ii) The above ageing test should be carried out by the approved test agency as specified in rule 126.
16. The vehicles shall be equipped with On-Board Diagnostic (BS VI WLTP- OBD) systems for emission control which shall have the capability of identifying the likely area of malfunction by means of fault codes stored in computer memory as per the procedure laid down in AIS-175 and as amended from time to time when that failure results in an increase in emission above the limits given in the following Table, namely:-
Table 3 On Board Diagnostic (OBD) Threshold for vehicles: BS-VI WLTP
| Sl. No. | Reference mass (RM) (2) (kg) | CO (mg/km) | NMHC/ (mg/km) | NOx (mg/km) | PM (mg/km) | ||||||
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) |
| 1. | Category | Class | PI | CI | PI | CI | PI | CI | PI (1) | CI | |
| 2. | N1 | I | RM ≤ 1305 | 1900 | 1750 | 170 | 290 | 90 | 140 | 12 | 12 |
| 3. | II | 1305 < RM ≤ 1760 | 3400 | 2200 | 225 | 320 | 110 | 180 | 12 | 12 | |
| 4. | III | 1760 < RM | 4300 | 2500 | 270 | 350 | 120 | 220 | 12 | 12 | |
| 1. For positive ignition, particulate mass applies only to vehicles with direct injection engines 2. Reference Mass shall be considered as Mass in Running Order +75kg. | |||||||||||
17. In-use performance ratio (IUPR) for BS VI vehicles complying to these rules, the in-use performance ratio
(IUPR) of a specific monitor M of the OBD systems shall be: IUPRM = Numerator/ Denominator
(i) Comparison of Numerator and Denominator indicates how often a specific monitor is operating relative to vehicle operation. Detailed requirements for tracking IUPR are given in AIS 175.
(ii) If, according to the requirements specified in AIS 175, the vehicle is equipped with a specific monitor M, IUPRM shall be greater or equal to the following minimum values.
(a) 0.520 for evaporative emission purge control monitors;
(b) 0.336 for all other monitors;
(c) 0.260 for secondary air system monitors and other cold start-related monitors.
18. In service compliance of vehicles shall be as per the procedure laid down in AIS175 and as amended from time to time.
19. For the vehicles complying with these Rules, real-world driving cycle emission measurement using PEMS shall be carried out for vehicles as per the procedure laid down in AIS 175 as amended from time to time, for all models during Type Approval. The RDE Conformity Factor (CF), shall be as per the following Table, namely:-
Table 4 Conformity Factor (CF) : BS VI-WLTP
| Sl. No. | Pollutant | CF pollutant |
| (1) | (2) | (3) |
| 1. | NOx | 1 + margin (3) NOx With margin NOx = 0.43 |
| 2. | PN (1) | 1 + margin (3) PN With margin PN = 0.5 |
| 3. | CO (2) | - |
1. Applicable for: Positive Ignition (Direct Injection) engines and Compression Ignition Engines only
2. CO emissions shall be measured and recorded at RDE tests.
3. Margin is a parameter taking into account considering the additional measurement uncertainties introduced by the PEMS equipment.
20. The CNG or Bio-CNG or HCNG Vehicles shall meet all the safety requirements as per AIS 024, AIS-028 Revision 1 as applicable.
21. The compatibility of the vehicle to the level of Ethanol blend of E85 and E100 shall be defined by the vehicle manufacturer, and the same shall be displayed on the vehicle by putting a clearly visible sticker as per AIS 171:2021.
22. All the gasoline-fuelled mono-fuel and Bi-Fuel Vehicles with Positive Ignition Engines, including Hybrids, shall be certified with Ethanol (E20) fuel.”