New Delhi: A study examining the impact of E20 petrol on older E10 compliant vehicles has found that prolonged use of the higher ethanol blend may cause deterioration of certain rubber components in the fuel system. The findings indicate that parts such as hoses, gaskets, seals and O rings could experience wear and may require replacement in some vehicles.
The report, which served as a technical reference during the rollout of E20 petrol, stated that the higher ethanol content had no adverse impact on metallic components across the vehicles tested. It also found that evaporative emissions and tailpipe emissions remained within prescribed limits, while overall vehicle startability and drivability continued to perform satisfactorily.
Engine durability tests, however, produced mixed results. One Bharat Stage IV engine completed testing with acceptable performance using E20 fuel. In another case, a Bharat Stage VI turbocharged engine developed an issue after 265 hours of testing. During additional durability assessments conducted by two passenger vehicle manufacturers, one completed 400 hours of testing without any problems, while another recorded a thermomechanical failure of an exhaust valve after a cumulative 809 hours of testing. Experts involved in the evaluation noted that such failures may not necessarily be linked to the fuel itself and pointed out that engine durability tests are generally conducted over much longer durations.
The study also found that engine durability tests conducted by three two wheeler manufacturers showed no significant issues, with vehicle performance remaining acceptable while using E20 petrol.
According to the findings, vehicles running on E20 recorded fuel consumption that was between two and six per cent higher than those using E10, although the extent varied across different models.
The report comes amid continuing debate over higher ethanol blended fuels. The government has maintained that India’s ethanol blending programme is based on extensive scientific evaluation and regulatory safeguards. It has also stated that E20 petrol was introduced only after detailed testing and has rejected claims that the fuel causes widespread engine damage or affects vehicle insurance coverage.
