Performance, emission and combustion characteristics of an indirect injection (IDI) multi-cylinder compression ignition (CI) engine operating on neat jatropha and karanj oils preheated by jacket water

► A multi-cylinder IDI type CI engine was used to test jatropha and karanj oils. ► Jacket water was used to preheat the plant oils. ► Better performance and emissions were observed than typically reported with DI engines. ► Both jatropha and karanj showed similar performance and combustion characteristics. ► Stable combustion and minimum coking were observed after 50 h operation.