Existing ecofriendly apprehensions about climate change have directed scientists to discover plant-based vegetable oils for use as fuels, such as straight vegetable oils and their biodiesels, because of their renewability, nontoxic nature, biodegradability, and environmental friendliness. This experimental study intended to reveal the tribological aspects of 90 °C preheated Jatropha curcas straight vegetable oil (PHSVO90) used in a 7.35 kW, 1000 rpm constant speed indirect injection (IDI) diesel engine and likened to conventional diesel operation by conducting an elongated term durability examination for 512 h as per IS:10000 standards. Tests were performed under encoded loading cycles in two segments: one with PHSVO90 and the second one with conventional diesel operation (CDO). Following the completion of these tests, all essential engine components were disassembled to assess physical deterioration and the accumulation of carbon deposits. Due to their different chemical compositions, PHSVO90 and diesel showed noticeable differences in their properties. PHSVO90 had a higher amount of carbon deposits, measuring 6.3 g. It also had a total acid number (TAN) of 9.11 mg KOH/g, a density of 986 kg/m 3 , and a viscosity of 381 cSt. In addition, an inductive plasma-based atomic emission spectroscope detected a greater amount of metal wear debris from spectrum metals with PHSVO90. The elements Fe, Cr, Al, Cu, Mg, and Pb exhibited concentrations 1.49×, 1.37×, 1.19×, 1.37×, 1.2×, and 1.18× higher, respectively, than those recorded during typical diesel operation. Wear of PHSVO90 fuel engine components like the cylinder head, cylinder bore/liner, piston, Gudgeon pin, small end bush of the connecting rod, big end bearing, crankshaft bearing, connecting rod bearing, and inlet and exhaust valves, along with guides, was detected to be marginally advanced compared to CDO. As per identified results, an appropriate maintenance protocol was developed for the PHSVO90 application. It is observed that, without any extensive modifications, PHSVO90 oil has proven to be a good substitute for IDI engines.
