Page 224 - The Central Motor Vehicles Rules, 1989

196 THE CENTRAL MOTOR VEHICLES RULES, 1989 RULE 115

(11) For Diesel vehicles, the emission of visible pollutants (smoke) shall not
exceed the limit value of smoke density, when expressed as light absorption
coefficient for various nominal flows as given in Annex I to sub-rule (9) of
rule 115 when tested at constant speeds over the full load. These smoke
limits are without correction factor and engines are to be tested with
conditioned air supplied to the engine to maintain atmospheric factor at
0.98 to 1.02.
(12) The engine power shall be measured on engine dynamometer and the
measured power shall conform to the power specified in AIS 137 as
amended from time to time, when tested as per the procedures laid down
in 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:—
TABLE
Deterioration Factor shall be as given below: BS VI
Engine Category Assigned Deterioration Factor
CO THC NMHC NOx HC+ Particulate Particle
NOx Matter (PM) Number
(PN)
Positive Ignition 1.5 1.3 1.3 1.6 – 1.0 1.0
Compression 1.5 – – 1.1 1.1 1.0 1.0
Ignition
(i) Alternatively, the vehicle manufacturer may opt for a vehicle ageing
test of 1,60,000 km or bench ageing durability test, for evaluating the
Deterioration factor as per AIS 137 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
137
(iii) The maximum lap speed at 10th lap and at 11th lap shall be 72
km/hour and 90 km/hour respectively.
(iv) The above ageing test should be carried out by the approved test
agency specified in rule 126.
(16) The vehicles shall be equipped with On-Board Diagnostic (BS VI - 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 137 and as amended from
time to time when that failure results in an increase in emission above the
limits given in the following Tables below:—
(i) OBD Threshold for BS VI vehicles manufactured on or after 1st April
2020: