An ARAI study, which hasn't been made public, found that E20 petrol's usage in E10-compliant vehicles may damage rubber parts of fuel-system components, TOI reported. The study, which called for the rollout of E20, said parts like hoses, gaskets, seals and O-rings "may need replacement". BS-IV engine's performance with E20 was acceptable, but issues were observed with BS-VI turbocharged engines.