Ford Motor Co. still hasn't launched the first V-6 version of its promised EcoBoost engine, but sources say the automaker already is putting the finishing touches on a 2.0-liter four-cylinder version of the economical motor, which they say is likely to debut on the Ford Fusion.

EcoBoost combines two technologies -- turbo-charging and direct fuel injection -- to produce more horsepower from a smaller engine. Ford plans to roll out the first EcoBoost engine, a 3.5-liter V-6 that delivers the power of V-8, on the 2010 Lincoln MKS next summer.

Ford spokesman Said Deep confirmed that Ford is developing a four-cylinder version, but said it was "too early to discuss displacements" or what vehicles might get the new engine.

"It's all about delivering the fuel economy customers want without sacrificing performance," Deep said. "The four-cylinder will deliver a good blend of both for customers."

Product analyst Jim Hall of 2953 Analytics LLP in Birmingham said the four-cylinder version should deliver the power of a six-cylinder engine with significantly better mileage. He said Ford also is developing a 1.4-liter EcoBoost based on the naturally aspirated 1.4-liter it already uses in Europe.

Ford is not the only company combining these technologies, but most of its competitors are using them to boost performance, not fuel economy. The Dearborn automaker is using them to replace larger motors with smaller ones.

It is a strategy Ford first unveiled as gasoline prices hit record highs, but Hall said it still makes sense with fuel prices approaching lows not seen in years.

"When they started work on what became EcoBoost, gas prices were still relatively low," he said. "It's a better way to meet emissions standards and CAFE standards and still give customers the performance they want."

Hall said the four-cylinder version of the EcoBoost will likely be introduced on the mid-sized Ford Fusion sedan, probably in 2010.