Environmental degradation and the depletion of oil reserves are serious worries around the world, particularly in developing countries such as India, which primarily imports oil. Because petrol and diesel are the most commonly used fuels in India, finding a suitable replacement is an urgent need. Essential oils are currently gaining popularity in this area. Orange peel oil is appropriate for CI machines, and it is gaining popularity in India due to its probable for large-scale hire and comparatively little environmental impact. In this work, orange peel oil is extracted via steam distillation and incorporated with diesel at a 20 percent ratio, denoted by the symbol OPO20. Experiments are conducted on a single-cylinder, water-cooled, four-stroke Kirloskar AV-1 CRDI diesel engine that is coupled with an eddy current dynamometer as a loading device and other necessary apparatus.. On a test engine, the effects of fuel injection pressure on the performance, emission, and combustion characteristics of a common-rail direct injection (CRDI) engine using OPO20 were investigated at 300, 450, 600, 750, and 900bar fuel injection pressures.