Nissan might be investing heavily in its electric car program, but the automaker hasn't forgotten hybrid vehicles completely.

In fact, the company is set to launch one hybrid or plug-in car per year for the next few years, allowing it to compete in a market where hybrid vehicles are gaining increasing market share.

Joining existing vehicles like the 2012 Infiniti M35h, Nissan is developing a range of hybrids and is set to implement mild hybrid technology across its range.

First to hit U.S. shores is likely to be the front-wheel drive Infiniti JX Hybrid.

We recently drove a prototype of the luxury hybrid crossover in Japan. It pairs a supercharged 2.5-liter four-cylinder with a single-motor hybrid system, boosting torque and allowing the car to drive on electric power alone under light loads.

That's the theory anyway, though we found it very difficult to run the car entirely in electric mode.

Following the Infiniti JX, Automotive News suggests a plug-in hybrid will follow in 2015 (though Nissan is revealing no details as yet), and the company aims to release at least one hybrid a year over the next several years.

The increase in hybrids and plug-in hybrids at Nissan is thought to be a symptom of slow full-electric vehicle sales.

Even so, Nissan still believes that some form of electric propulsion is the future.

"All vehicles need some form of electrification," said Mitsuhiko Yamashita, Nissan's executive vice president for global R&D, "Motor assistance really is key. Otherwise they can't meet fuel economy requirements beyond 2015."

Meanwhile, 'micro hybrid' technologies like stop-start and brake energy regeneration are expected to permeate throughout Nissan's range, improving the fuel efficiency of even regular models.

Called S-Hybrid--S for 'smart' or 'simple'--Nissan says the technology can boost economy by around 10 percent, for a cost of around $1,910 or less.

What do you think of Nissan's plan to expand its hybrid range? Leave your thoughts below.

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