Nissan is working hard to lower the emissions from all vehicles, not just their electric Nissan Leaf. The company will soon implement an advanced supercharged engine matted to a hybrid powerplant.

This hybrid, which will be available on cars at Nissan Sunnyvale one day, connects a supercharged 2.5 liter 4-cylinder engine with CVT transmission, electric motor, and lithium-ion battery. Details on fuel economy will depend on the vehicles themselves, though Nissan "seems to have set out to build a system that is equal parts performance and fuel economy."¹

Other reports suggest the new system will debut in next-generation Nissan Altima or Nissan Maxima vehicles, working with all engine types between 2.0 and 3.5 liters, as well as Nissan's performance V6.

Superchargers work by providing more baseline power than turbochargers. They deliver huge amounts of low end torque to hybrid engines, making them more powerful and pleasing most of the anti-hybrid crowd.

Source: ¹http://gas2.org/2011/10/17/nissan-develops-supercharged-hybrid-system/