The I.O.R. 2.5 cc diesel of the late 1950’s was the only model engine to reach series production in any significant quantity in the Eastern European country of Romania. Built by a long-established optical equipment firm located in Bucharest, this engine was essentially a close copy of the famous Webra Mach I diesel. It was quite well made, also performing at a comparable level to that of its Webra inspiration. However, it never seems to have been the subject of a serious attempt to export it to other countries, hence being a relatively rare engine today. A detailed article about the I.O.R. 2.5 cc diesel, including a full bench test, may be found elsewhere on this website.