Only BS6, CNG, and EVs Allowed: Delhi Shuts Borders to High-Emission Vehicles Amid Toxic Smog

With the air in Delhi refusing to budge from the severe range for days, the government has rolled out some of its toughest vehicle restrictions yet. From Thursday, December 18, only BS6-compliant cars, CNG vehicles, and electric vehicles can operate in Delhi and pass into the city from outside. BS3 petrol and BS4 diesel vehicles from outside Delhi are thus effectively barred-under GRAP Stage IV.

Key move: Ban BS3 and BS4 Vehicles

Delhi's Environment Minister Manjinder Singh Sirsa had issued an order saying that from December 18, only BS6-compliant vehicles could enter Delhi. That means BS3 and BS4 vehicles registered outside the city were not allowed to come in.

While in stage IV, BS3 petrol and BS4 diesel vehicles are banned in Delhi-NCR from movement unless it is providing essential or emergency services-ambulances, fire, police, etc.

It includes all private cars and a majority of commercial transports entering Delhi, thus tightening the reins compared to previous restrictions.

No Petrol or Diesel without PUC (Pollution-under-control Certificate)

Fuel pumps in Delhi have been instructed to deny fuel to any vehicle which doesn't possess a valid PUC certificate.

From the same Thursday, vehicles without valid PUC will be denied refueling, thereby compulsorily making the owners renew the emission checks before using their vehicles.

It targets high-emission, poorly maintained vehicles that worsen smog but can continue to operate because of lax enforcement.

Why Stage IV GRAP Was Triggered?

Delhi-NCR has been reeling under persistent toxic smog, poor visibility, and health advisories during the past several days with the Air Quality Index crossing 400 at various places and, until now, edging close to the "Severe Plus" mark above 450.

On India's AQI scale,

• -101–200: Moderate

• 201–300: Poor

• 301–400: Very Poor

• - >400: Severe

The Commission for Air Quality Management consequently activated GRAP Stage IV, the most stringent level, devised for AQI near or above 450 across the NCR.

Which Vehicles Are Allowed and Which Are Restricted?

Restricted Under GRAP Stage IV

• BS3 petrol vehicles: banned across Delhi-NCR, except in case of essential/emergency services.

• - BS4 diesel vehicles: completely banned in Delhi-NCR, except for essential/emergency services.

• The private vehicles in these categories are not allowed to enter Delhi, along with many commercial ones.

Allowed Under GRAP Stage IV?

- BS6-compliant vehicles-petrol and diesel: The operation of these vehicles will be allowed and can enter Delhi. 

Only CNG and electric vehicles: without any restriction. Commercial vehicles running on LNG, CNG or electricity, as well as BS6 diesel commercial vehicles, can enter. 

Significance and Implications 

This move accelerates the shift toward cleaner fleets-BS6, CNG, EVs-in response to recurring winter smog episodes. It also heralds more stringent enforcement of PUC norms, making emission compliance the eligibility not merely for legality but even for access to basic fuel. What this will mean for commuters and transporters is that: - Inconvenience to the owners of BS3/BS4 vehicles which are older, particularly from outside Delhi. Greater use of public transport, CNG fleets, and pooling, at least until Stage IV is in effect.