Development of Flex Fuel Engine for Indian Market

This paper presents the methodology and outcomes of modifying a 1.2L naturally aspirated (NA) engine to enable flex-fuel compatibility, targeting optimal performance with ethanol blends ranging from E20 to E100. Ethanol is being increasingly promoted due to its potential to reduce greenhouse gas emissions and to provide an additional source of income for farmers. As per the road map for Ethanol blending released by Govt. of India, there has been continuous increase in blending of ethanol in gasoline. An initial target of 20% ethanol blending in gasoline by April 2025 has already been achieved. This work is in alignment with the broader push for development of flex-fuel vehicles, which necessitates engine adaptations capable of operating on varying ethanol blends. The primary objective was to upgrade the engine, which can give optimum performance with both lower range of ethanol blends starting from E20 as per IS 17021:2018 standard till higher blends of up to E100 as per IS 17821:2022. The engine upgrade included several key modifications such as material upgradation of components directly coming in contact with fuel for ethanol resistance, optimization of the compression ratio, introduction of heated fuel rail system for cold start and redesign of intake camshaft to ensure compatibility and performance with ethanol-blended fuels. Additionally, the engine management system (EMS) was recalibrated with dedicated maps tailored to various ethanol blend levels, enabling efficient and reliable operation across a wide range of fuel compositions