Government of India has set up an ambitious net zero carbon emission target by 2070 in COP 26. To meet this target and to ensure energy security and energy sustainability, emphasis is being made to phase out petroleum derived fuels i.e. petrol, diesel etc. through sustainable alternatives. With all the environmental concern of diesel fuelled vehicles, it is a challenge to phase out them completely specifically from Heavy duty application due to their inherent attributes of high torque, efficiency and high range. Therefore, most pragmatic solution lies in reduction of carbon emission through fuel intervention and retain the characteristics of diesel fuelled vehicles. Efforts are under progress to explore the possibility of utilization of ethanol as blend in diesel fuels. This research work is focus on development and evaluation of ethanol blended diesel fuel in heavy duty engines. The ethanol and diesel are not miscible naturally so suitable agent was developed to make homogeneous mixture. Further, quantity of dosing was optimised and stable ED5 fuel i.e. 5%, v/v ethanol in diesel was developed and . Also, cetane improver was added to enhance the cetane number which was lowered due to blending of ethanol. Beside this, appropriate dosages of lubricity improver and corrosion inhibitor were added and stable ED5 fuel was developed. Further, with due consideration of inherent physicochemical properties of ethanol i.e. moisture ingress and corrosion, suitable engine oil was developed. BS VI compliant 6 Cylinder Turbo charged Heavy Duty Engine (800 Nm@ 1600 rpm, 160 kW@2400 rpm) was utilized and tested on Transient Engine Test Bench. Full Throttle performance (FTP), World Harmonized Transient Cycle (WHTC) and World Harmonized Stationary Cycle (WHSC) were undertaken to evaluate the performance and emission with diesel and ED5 fuel. There was 3~4% drop in torque in the lower speed range of 1000-1600 rpm, 1~2% drop in torque in the higher speed of 1700-2400 rpm and ~ 4-5% deterioration in brake specific fuel consumption (BSFC) observed with ED5 fuel compared to Diesel fuel. Significant emission reduction i.e. ~25% in Nitrogen Oxides (Nox), ~ 28% in Hydrocarbons (HC) and Particulate Matter (PM) were observed with ED5 fuel compared to diesel fuel. Further, to demonstrate the suitability of engine operation with ED5 fuel and to establish the engine oil credentials, 800 hrs engine endurance test was undertaken with ED5 fuel. Fresh engine oil was charged after proper flushing and endurance test was conducted through running of rayed load cycles. During engine endurance test, periodic engine performance and used engine oil samples were collected. Used engine oil analysis were undertaken and engine oil characteristics such as Kinematic Viscosity 40oC, Kinematic Viscosity @ 100oC, Total Base Number (TBN), Total Acid Number (TAN), Oxidation, wear metal analysis etc were measured. Engine performance was found satisfactory during engine endurance and negligible variation were observed in the rated torque & power. used engine oil analysis showed the stable engine oil behaviour throughout the endurance test and found suitable for ED5 application.