Sunita Somvanshi
The Supreme Court has dismissed a Public Interest Litigation (PIL) challenging India’s E20 ethanol-blending policy. During the hearing, the program was repeatedly described in court-room exchanges as a “logical progression” toward cleaner fuels, with this phrase used by counsel and government representatives during arguments. This ruling maintains the government’s plan despite concerns about older vehicles and engine compatibility.
The dismissed petition highlighted several technical issues with E20 fuel in vehicles manufactured before April 2023. NITI Aayog’s roadmap estimated fuel-economy penalties in the single-digit percent range, with approximately 6-7% for some four-wheelers not calibrated for ethanol.
Ethanol absorbs water from the atmosphere, which can create problems in fuel systems not designed with compatible materials. This property can lead to:
- Corrosion in metal fuel components
- Damage to rubber hoses and seals
- Clogged filters from loosened deposits
- Phase separation when fuel sits unused
For older engines without modern sensors, ethanol’s oxygen content can alter the effective air-fuel mix and lead to leaner running unless the engine is recalibrated. On engines that actually run lean, combustion temperatures can rise and power may fall, though properly tuned engines or those with ECUs that compensate for E20 may not experience these issues.
The Attorney General defended the policy by pointing to its economic and environmental benefits. According to Indian Sugar Mills Association (ISMA) data:
- ₹1.18 lakh crore has been paid to farmers through the program
- ₹1.36 lakh crore saved in foreign exchange
- 698 lakh tonnes of CO₂ emissions prevented
India reached its E20 goal in 2025 — five years ahead of the 2030 target in the 2018 biofuels policy, and consistent with NITI Aayog’s 2021 roadmap that targeted 2025.
Industry bodies contested the severity of the compatibility issues. SIAM Executive Director Prashant K. Banerjee stated: “Millions of vehicles are running E20… not a single breakdown reported.”
The Automotive Research Association of India (ARAI) found no evidence of mechanical failures due to E20. Both organizations suggest the real-world efficiency drop is closer to 2-4%, less than initial predictions.
Most vehicle manufacturers have committed to honoring warranties for E20-compatible models. The IRDAI has not issued any directive denying claims for E20-related damage, though coverage still depends on manufacturer policies.
India’s ethanol journey started in 2003 with E5 (5% ethanol) in select states, according to Ministry of Petroleum data. The current implementation puts India ahead of many countries:
- Brazil uses E27 as standard
- US uses E10/E15
- EU varies between E5 and E10
E20 was rolled out first in urban and semi-urban outlets; recent reports say it is now widely available across the country at many outlets.
Tests reported in some ARAI/government summaries show CO reductions of approximately 50% in two-wheelers and around 30% in some four-wheel tests. Hydrocarbon emissions are reduced by roughly 20% compared to unblended petrol.
These environmental gains come alongside the economic benefits for farmers and supporting industries like distilleries, transport, and storage infrastructure.
For consumers with pre-2023 vehicles, experts recommend:
- Checking vehicle manuals or manufacturer websites for E20 compatibility
- Monitoring fuel system seals and tracking any mileage changes
- Using fuel from high-turnover stations to reduce moisture absorption risk
- Following manufacturer maintenance recommendations for ethanol-blended fuels
The Supreme Court rejected the petition’s demand for an ethanol-free option, but it also pressed authorities on ensuring consumer awareness and appropriate labeling at pumps. The ruling means E20 will continue its nationwide rollout as planned, becoming standard at pumps across India despite the technical concerns raised about older vehicles.
