Chief Economic Adviser V Anantha Nageswaran has proposed restoring E10 petrol for older two-wheelers, while cautioning India against increasing ethanol blending beyond E20 without first assessing its wider impact on agriculture, water resources and food security.
In a column published in The Indian Express, Nageswaran and Department of Economic Affairs consultant Akash Poojari argued that India's ethanol debate needs to move beyond questions about vehicle compatibility.
The bigger issue, they said, is what greater ethanol demand could mean for cropping patterns, land use, water consumption and the availability of crops for food and animal feed.
Why E10 is being proposed for older vehicles
The authors estimate that around 75 million to 80 million older two-wheelers, particularly pre-BS-IV carburettor-equipped vehicles, are still on Indian roads.
According to their argument, carburettor-based engines cannot automatically adjust the fuel-air mixture to account for the additional oxygen associated with higher ethanol blends.
This could potentially result in a leaner fuel mixture and higher engine temperatures. Older rubber and other components may also not have been designed for prolonged exposure to higher ethanol concentrations.
The authors argue that retrofitting such vehicles with ethanol-compatible components is possible, but doing so across tens of millions of vehicles would take considerable time.
Their proposed solution is therefore to make E10 available for this older fleet while E20 remains the standard blend for newer compatible vehicles.
What is E20 petrol?
E20 refers to petrol containing 20% ethanol blended with 80% petrol.
India reached its 20% ethanol-blending target earlier than originally planned. The programme has been promoted as a way to reduce crude-oil imports, conserve foreign exchange, create an additional market for agricultural produce and support ethanol producers.
However, moving to higher blends such as E27 or E30 would require substantially more ethanol.
That raises a crucial question: Where will the additional ethanol come from?
The food-versus-fuel problem
Ethanol in India is produced from several agricultural feedstocks, including sugarcane, maize, rice and other grains.
These crops already have competing uses.
Maize, for example, is an important component of poultry and livestock feed. If more maize is diverted towards ethanol production, the supply available for animal feed could decline unless farmers increase production.
That could push up feed costs and eventually affect the wider food economy.
The authors argue that this trade-off becomes increasingly important if India considers ethanol blends above E20.
In simple terms, more ethanol demand could mean more agricultural land being directed towards fuel rather than food or feed.
Sugarcane adds another layer to the debate
Sugarcane is another major ethanol feedstock, but it is also a water-intensive crop.
The ethanol debate therefore involves not just food versus fuel, but also water versus fuel.
If more sugarcane is used for ethanol, there can be implications for sugar availability. Conversely, reducing sugarcane's contribution to ethanol means India may need to rely more heavily on maize and other grain-based feedstocks.
This creates a chain of interconnected choices:
More ethanol → more feedstock demand → greater pressure on crops → possible food/feed competition → greater land and water requirements.
Why water matters
Nageswaran and Poojari argue that policymakers should consider the full water footprint of ethanol, rather than looking only at the water consumed inside an ethanol plant.
Much of the water requirement occurs before the crop reaches the distillery.
For water-intensive crops such as sugarcane, increasing fuel demand can therefore influence how agricultural water is allocated.
The authors warn that once farmers change cropping patterns and infrastructure is built around ethanol production, reversing those decisions may be difficult.
Government continues to back E20
The proposal does not mean the government has abandoned E20.
The government has defended E20, citing extensive testing and arguing that there is no evidence of widespread engine damage in compatible vehicles.
It has also highlighted the benefits of ethanol blending, including reduced crude-oil dependence, foreign-exchange savings and additional demand for agricultural products.
The CEA's argument is instead about what should happen next.
Rather than immediately pursuing E27, E30 or higher blends, the authors want India to first calculate the broader economic costs of additional ethanol demand.
What the proposal means for vehicle owners
For owners of newer vehicles designed to operate with E20, the policy remains unchanged.
For owners of older carburettor-equipped two-wheelers, the proposed approach would provide an alternative:
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Older vehicles: E10 option
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Newer compatible vehicles: E20
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Retrofits: Gradual transition towards ethanol-compatible components
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Higher blends: Greater scrutiny before implementation
The proposal could therefore address two separate issues at once: concerns around older vehicles and the increasing agricultural demand created by ethanol policy.
The bigger question for India's ethanol policy
The debate is ultimately no longer just about whether E20 petrol damages older engines.
It is about the opportunity cost of producing more ethanol.
India has to balance several objectives:
Energy security vs agricultural demand
Crude-oil savings vs food and feed prices
Farmer demand vs water availability
Higher ethanol blending vs land-use pressures
The CEA's intervention suggests that before India moves beyond E20, policymakers may need to ask a broader question: how much land, water and agricultural production is the country willing to commit to fuel?
For now, the proposal is to retain E20 as the broader policy while considering E10 for India's older vehicle fleet and carefully examining the consequences of any future increase in ethanol blending.
