The government‑backed joint study by IOCL, the Indian Institute of Petroleum, the Society of Indian Automobile Manufacturers and the Automotive Research Association of India examined the impact of E20 fuel on Indian vehicles.
Key Developments
- Legacy vehicles (manufactured before 2023) showed no significant loss in performance, drivability or abnormal wear when run on E20. The only noted exception was some BS‑III models made before 2016, where rubber parts may need replacement during routine service.
- Extended durability tests (400‑806 hrs) on a BS‑VI turbo‑charged engine showed issues after ~265 hrs, suggesting some engine configurations need closer scrutiny.
- Automakers estimate a 3‑5% drop in mileage with ethanol blending to E20, due to ethanol’s lower energy content.
- Mechanics report increased fuel‑system problems (clogged injectors, filter blockages, O₂ sensor failures) and higher repair costs since the April 2025 rollout, though they caution that ageing vehicles and fuel contamination may also be factors.
Important Facts
Vehicles manufactured from 2023 onward that are certified as E20‑compatible have undergone redesign of pumps, injectors, seals and engine‑management software. The redesign is validated through extensive durability testing before certification.
Petrol dealers warn that ethanol’s hygroscopic nature makes E20 prone to water absorption, leading to phase‑separation in poorly maintained underground tank