Mitsubishi says that with this combination, the three models show a 12% improvement in fuel efficiency in the Japanese 10-15 mode driving cycle. One of the most important features of the new 1.8-liter engine is the latest iteration of the company's MIVEC system that continuously regulates intake valve lift, opening duration and timing. Before the 4J10, Mitsubishi employed two types of MIVEC systems - one that switches between different valve lifts and valve opening durations according to engine speed; another that varies the valve opening timing on a continuous basis. The new MIVEC system combines the above 2 systems. In JDM specification, the 1.8 liter SOHC unit is rated at 139hp at 6000 rpm and 172Nm at 4,200 rpm. The specs are comparable to Honda’s R18A power plant, which developes 140hp at 6300rpm and 174 Nm at 4300rpm. However, considering that the R18A was developed some 5 years ago, the 4J10 specs do not impress. Mitsubishi should have worked on a revised GDI (Gasoline Direct Injection) system that the company introduced in the late 1990s as well.
As for Mitsubishi's new Auto Stop & Go system, while the current version can only be used in conjunction with a manual gearbox, the latest variant has been developed for use on continuously variable transmissions (CVT) as well.