Mitsubishi has announced the development of two new fuel saving technologies: a 1.8-litre petrol engine with MIVEC variable valve timing and a new stop-start system.

The 4J10 MIVEC power unit has a single overhead camshaft with the latest version of Mitsubishi's variable valve timing system. This is designed to continuously regulate intake valve lift, duration and timing. It is claimed to give improved fuel economy with no loss of performance. Power and torque figures for the new motor are 137bhp and 129lb.ft. On the Japanese market driving cycles the new engine is claimed to be 12% more efficient.

The Japanese market Mitsubishi ASX (called RVR over there) is the first model to receive the new engine.

Auto Stop & Go (AS&G) has been fitted to some manual transmission versions of the ASX and Lancer. The new system is designed to work with the Continuously Variable Transmission (CVT). A new control system has integrated the operation of AS&G along with the transmission, engine, stability control and climate control. The electrical system features a more durable battery and DC/DC converter to prevent breaks in audio system sound and to stop the navigation system resetting when the engine restarts.

Technologies to save fuel are part of Mitsubishi's strategy to reduce new vehicle CO₂ emissions by 25% by 2015 and 50% by 2020 (compared to a 'globally weighted average' for 2005).