Bring back E10 for older vehicles. Work out food-versus-fuel trade-off

A complaint has been circulating online that the government's E20 petrol damages engines and reduces fuel efficiency. While the fear is loud, the core argument is incorrect. However, dismissing this concern is a mistake because it highlights a real issue and a larger question. Initially, the engine's performance is not affected by E20, as ethanol provides around two-thirds of the energy of petrol.

The energy loss is minimal and does not indicate any malfunction. Additionally, ethanol reduces carbon monoxide and unburnt hydrocarbons, which is beneficial for the environment. Durability is not a concern either, as tests conducted by the US Oakridge National Laboratory and India's ARAI have shown no increased wear on vehicles not rated for E20.

The main exception is India's approximately 75 to 80 million older two-wheelers with carburettors. These vehicles cannot adjust for the extra oxygen in the blend, leading to overheating and degraded rubber seals. Revamping these seals with ethanol-compatible ones is inexpensive but would be a time-consuming process for 75 to 80 million vehicles.

The original plan was to maintain a lower blend for these vehicles, but this option has since disappeared. Restoring a lower blend, such as E10, alongside the option for E20 would address most public concerns, decrease overall ethanol usage, protect existing vehicles during the retrofitting process, and allow time for the transition.

When considering the broader blend levels, such as E27 or E30, the question arises of how much further blending should go. Moving to these higher blends raises concerns about competing with food production, as ethanol from maize competes with maize, soybean, groundnut, and mustard for land. While maize provides half of India's ethanol, grains account for nearly 67 percent, pulling land away from other crops.

Furthermore, water usage for ethanol production is a critical aspect that should be addressed. The green water, or rainwater, is often overlooked in the discussion. The climate case for blending beyond E20 is also unsettled, as Indian life-cycle studies do not agree on the cleaner nature of grain ethanol compared to other alternatives.

In conclusion, the decision of the blend level should be guided by weighing the benefits and drawbacks. Some aspects can be adjusted within a season, while the blend level is immutable. As irreversible changes are slow and costly, it is prudent to prioritize reversible measures first and postpone irreversible ones until a comprehensive cost-benefit analysis is conducted.