It's no secret that all auto manufactures are looking to boost the fuel efficiency of their vehicles thanks to looming CAFE requirements. Companies are looking at a wide variety of options from diesels to hybrids to fully electric vehicles to downsized gasoline engines with turbochargers. 

Ford is using traditional, naturally aspirated engines in the subcompact Fiesta and compact Focus to achieve roughly 30 mpg in the city and around 40 mpg on the highway. Likewise, the current generation Fusion Hybrid is no slouch either, with a city rating of 41 mpg and a highway rating of 36 mpg. 

However, according to Ford Inside News, Ford is looking to boost the city fuel economy of the next generation Fusion Hybrid to as high as 48 mpg. That would put it within striking distance of the eccentric Toyota Prius, which is rated at 51 mpg in the city. There's no word on how much the highway fuel economy will increase, but we'd guess that an even 40 mpg isn't out of reach. 

Ford should be able to hit these fuel economy targets thanks to a new lithium-ion battery pack which will replace the existing nickel-metal hydride (NiMH) unit. The lithium-ion battery pack should be lighter and more compact, which should help keep overall weight down and reclaim some cargo space (the current Fusion Hybrid has a mere 11.8 cu ft of trunk space compared to 16.5 cu ft for its non-hybrid counterpart).

The next generation Fusion is expected to be unveiled at the 2012 Detroit Auto Show and will go on sale shortly thereafter. The 2013 Fusion will be a unifying design as it will replace both the North American Fusion and the Mondeo which is sold in Europe.