The National Green Tribunal’s order on Monday, directing the Regional Transport Office in Delhi to de-register all diesel vehicles over 10 years old, comes as a ratification of oil market companies’ long-standing view that to improve air quality older cars need to be removed alongside providing higher quality fuels.

BS VI quality fuels Public sector oil marketing companies are in the midst of investing around ₹30,000 crore to upgrade their refineries and provide Bharat Stage (BS) VI quality fuels by 2020 across the country.

Blame game In the debate over improving air quality, automobile manufacturers have often laid the blame on lack of quality fuel being available, while oil marketing companies have, in response, said older and inefficient vehicles running on the roads means simply providing better quality fuel is not the only solution.

In February, Indian Oil Corporation had said in a statement, “While fuel quality is required to meet emission norms, suitable design of engines are essential to achieve the desired results… Though the country will be switching to BS VI vehicles from 2020, the impact on vehicular emission may not be significant immediately.

“The benefit of superior engines running with superior fuels will be gradual and it will be significant only when substantial percentage of BS VI compliant vehicles run on the road.”

Shifting of demand Meanwhile, industry analysts said it is unlikely that the move of de-registering of old vehicles will massively impact sales of diesel in the national capital.

“If the Regional Transport Office in Delhi de-registers them, they can always be sold in National Capital Region (NCR) or even somewhere else in the country. So the demand for diesel will not go down; it will either move to other centres or most likely remain within the NCR,” an analyst at a brokerage firm said on condition of anonymity.

Diesel sales in the NCR is almost double that of petrol sales for Indian Oil.

The company sold around 1.2 million tonnes of diesel in 2015-16, as compared to 0.572 million tonnes of petrol sales.