Even before Nissan introduced the Altima hybrid
late in 2006 using a licensed Toyota hybrid system, they started development work on their own in-house system. More recently, there were indications that the Nissan system might first appear on Infiniti models. Now it looks like the system that is being developed will follow the path of Porsche and GM's Two-Mode hybrid system and allow electric assist at higher speeds. What's not known is whether the motor will be able to run along with the engine for extra boost as the two-mode system does, or if it will be able to run solely on electricity at highway speeds as the Porsche system allows. The new hybrid is expected to appear on the next-generation Infiniti FX in about 2011.
[Source: Motor Authority]