From Diesel to Natural Gas: the Development of Heavy Duty CNG Engines

The technological development process of heavy-duty CNG engines for commerical vehicles is evaluated according to ten years of experience matured by Centru Ricerche Fiat and Iveco during the joint development of several applications of CNG engines in the power range from 80 to 230 kW. The first part of the paper reviews the basic choices, the engineering tools and the design solutions adopted; the second part shows the results achieved on the engine test beanch and on the vehicle. As results, Iveco CNG engines offer at the same time EEV emission levels, reliable operation excellent fuel consumption and significant CO2 reduction compared to their diesel counterparts.