What a total ban on diesel vehicles could mean in India

What is the background of this proposal?

The panel’s recommendations come in the wake of the government’s stated aim to reduce greenhouse gas emissions, and to produce 40% of its electricity from renewables as part of its 2070 net zero goal. Diesel currently accounts for about 40% of India’s petroleum products consumption, according to estimates by the Petroleum Planning & Analysis Cell.

The proposed ban will have a significant footprint — a large number of cities in India have more than 1 million people, and include not just the metropolitan centres, but also smaller towns and cities such as Kota, Raipur, Dhanbad, Vijayawada, Jodhpur, and Amritsar.

Who makes diesel cars in India?

Maruti Suzuki, the country’s largest passenger vehicle manufacturer, stopped making diesel vehicles from April 1, 2020, and has signalled that it does not have plans to re-enter this segment.

The diesel engine is, however, part of models sold by Hyundai and Kia, and Toyota Motor’s Innova Crysta range. Tata Motors, Mahindra, and Honda have discontinued production of 1.2-litre diesel engines; diesel variants are available only for 1.5-litre or higher engine capacity.

Since 2020, most carmakers have taken significant steps towards deleveraging their diesel portfolios. As a result, the contribution of passenger vehicles to overall diesel vehicle demand has fallen to just 16.5%, compared to 28.5% in 2013.

So what is the issue with the proposal?

It is not yet clear how the proposal for a ban, if accepted, will unfold and how practical it would be to implement. This is especially true in the case of medium and heavy commercial vehicles that are used for the transport of goods on highways, and for buses plying in most Indian cities, where diesel is the mainstay. Even if the ban on diesel for commercial vehicles were to have a longer transition time, significant disruption could still happen.

Around 87% of diesel fuel sales are in the transport segment, with trucks and buses accounting for about 68%. Uttar Pradesh, Maharashtra, and Haryana make up almost 40% of the diesel sold in India. While it seems easier at the moment to convert diesel trucks to compressed natural gas (CNG), there are certain limitations — including CNG being used for shorter distances, and its lower tonnage carrying capacity.

Also, many auto industry players argue that carmakers having a presence in the diesel segment are already in compliance with current emission norms, and have invested heavily to transition their diesel fleet from BS-IV to BS-VI emission norms.

What is the reason people prefer diesel vehicles?

The higher fuel economy of diesel engines over petrol powertrains is one factor. This stems from the greater energy content per litre of diesel, and the inherent efficiency of the diesel engine.

Diesel engines do not use high-voltage spark ignition (spark plugs), and thus use less fuel per kilometre, as they have higher compression ratios, making it the fuel of choice for heavy vehicles.

Also, diesel engines offer more torque (rotational or turning force), and are less likely to stall as they are controlled by a mechanical or electronic governor, thereby proving to be better for haulage.

Why are carmakers moving away from diesel?

The higher compression ratio of diesel engines means there are increased emissions of oxides of nitrogen (NOx), which is one of the main drawbacks of diesel engines versus petrol. The biggest blow for diesel, though, has been an external trigger — the Volkswagen emissions scandal, which led to an increase in the negative perception against diesel across markets, including India.

Also, the reason why Maruti Suzuki and other carmakers announced an exit from the diesel segment was the rollout of the new BS-VI emission norms from April 1, 2020, and the prohibitively high cost of upgrading diesel engines to meet the new standard. The government’s decision to leapfrog directly from BS-IV to BS-VI is the reason carmakers such as Maruti Suzuki cite for the unviability of retaining diesel in their portfolio.

Didn’t petrol engines too need upgrades as a result of the shift to BS-VI?

While petrol vehicles needed upgrades for this transition, these were limited to catalysts and electronic control upgrades. But for diesel vehicles, the upgrades were more complicated and entailed higher costs. Carmakers had to put three pieces of equipment — a diesel particulate filter, a selective catalytic reduction system, and an LNT (Lean NOx trap) — to meet the BS-VI norms, all at the same time. This was vital to curb both PM (particulate matter) and NOx emissions as mandated under the BS-VI norms.

For most carmakers, the economics of the conversion simply did not make it worthwhile to continue with the diesel option after the transition to BS-VI. “For us, diesel is completely out… We did study the market, but we found that it didn’t make sense given the future regulatory environment, the cost would have been really high and it just didn’t make sense,” CV Raman, chief technology officer, Maruti Suzuki India had told The Indian Express in an interaction in March.

And what about the buyers of diesel vehicles?

There is the issue of the price of diesel, and consequently, of running the car. The Indian carbuyer’s romance with diesel powertrains lasted nearly a decade, with diesel cars accounting for 48% of passenger vehicle sales in the country in 2013. The main reason was the sharply lower price of diesel as compared to petrol — a yawning Rs 25 per litre at its peak.

But this changed when the decontrol of fuel prices started in late 2014. The price difference has since come down to around Rs 7 per litre — the closest the two fuels have been in price since 1991. Consequently, diesel cars accounted for less than 20% of overall passenger vehicle sales in 2021-22, less than half the share they had five years ago.

So what is the upshot, overall, of this proposal?

A move towards a phasing out of diesel — and ultimately petrol as well — vehicles is in keeping with action by most federal governments across the world.

In the case of India, however, automotive experts foresee difficulties in implementing a total ban on diesel because, (a) carmakers — and oil companies — have invested heavily in transitioning to BS-VI and all that investment could go down the drain if a complete ban were to be implemented and; (b) in the commercial vehicles segment, where diesel penetration is very high and alternative fuels options such as electric vehicles, CNG, liquified natural gas (LNG), and hydrogen are still only being explored, and a total ban would cause serious disruption.

The Energy Transition Advisory Committee report has said that “LNG has the potential to replace both diesel and CNG in heavy-duty vehicles and thereby reduce GHG emissions. Its push in both medium and heavy-duty vehicles, despite cost constraints and higher payback periods, can be a gamechanger for the Indian logistics market”, alongside a recommendation for an EV push and leveraging hydrogen as a motive fuel.

Automakers have consistently maintained that the government’s approach should be technology-agnostic, and that interventions should be restricted to prescribing stringent operational standards, including emission norms. If a particular technology or fuel type is not able to meet the standards, then it should be phased out, rather than proposing a complete ban on a technology platform, an executive with a car company said.

Oil marketing companies claim that emission standards under BS-VI have necessitated oil refineries to substantially reduce the level of sulphur in diesel, and that the Bureau of Indian Standards (BIS) has brought out the specification for “diesel with 7 per cent biodiesel”, which further lowers the emission footprint of diesel.