Higher ethanol blends are restricted to vehicles designed and certified for them; existing owners will not have to switch fuels or modify their. The Ministry of Road Transport and Highways (MoRTH) has changed certain vehicle classification thresholds, fuel specifications, and technical references used in emission-related tables and. MoRTH approves higher ethanol blends, including E100 flex-fuel for certified vehicles, with updated rules, weights, and testing provisions.