New Delhi: Certain rubber parts and gaskets in older BS-III vehicles manufactured before 2016 may require replacement when using E20 petrol, the Centre informed the Rajya Sabha on Wednesday. However, it maintained that the ethanol-blended fuel does not significantly affect overall vehicle performance or require engine modifications. According to the minister, the studies found that BS-VI vehicles continued to comply with emission norms when operated on E20 fuel. Gadkari said the studies found no significant impact of E20 on vehicle performance, including in older vehicles. The clarification comes weeks after an ARAI study, which has not yet been made public, reportedly concluded that E20 fuel could affect rubber parts in vehicles originally designed for E10 petrol.