This paper presents a 2.5L V6 aluminum cylinder block engine that has been developed for use in the next HYUNDAI SONATA vehicle. The major objective in developing this new engine was to achieve high power,especially high torque at low to mid speed range, quiet engine operation, reliability and good fuel economy. The basic construction of the engine is characterized by its 60-degree V6 configuration, compact combustion chamber and simple variable intake systems. The new engine has been designed to comply with the tougher TLEV emission standard, OBD-II requirements and California's new evaporative emission standards. This paper will introduce various technologies used in this engine that increased engine performance while reducing emission and improving fuel economy and NVH characteristics, and will discuss the engine construction, principal component parts, major development objects and test results.