In 2011 we brought you the exclusive that a four-cylinder engine would be offered in the redesigned 2015 Ford Mustang, and that the engine would be a turbocharged 2.3-liter unit.

A year later we learned that the 2.3-liter engine would be an enlarged version of the 2.0-liter EcoBoost unit currently fitted to the Ford Focus ST and rated at 252 horsepower.

And most recently, we learned that the 2.3-liter EcoBoost engine would be shared with a next-generation Ford Focus RS, where it would deliver in excess of 300 horsepower.

Now Edmunds is reporting that the 2015 Ford Mustang equipped with this engine will only be offered in Europe, where gasoline prices are often double what they are here. For customers in the U.S., the Mustang will continue with V-6 and V-8 engines.

The 2.3-liter EcoBoost engine in the Mustang is expected to output around 300 horsepower, though it will almost certainly be tuned to deliver more in the new Ford Focus RS. The last version of the ultimate Focus developed as much as 345 horsepower, all of it sent to the front wheels.

European Mustang fans seeking more power will still have the option of a V-8, the report also states.

Ford Motor Company [NYSE:F] is currently testing some early mules for its 2015 Mustang, spy shots of which you can access here. The new car’s design is expected to borrow elements from Ford’s Evos concept of 2011 but it will still be clearly recognizable as a Mustang.

Under the new sheet metal, the current Mustang’s rear live axle suspension will make way for a fully independent setup. It’s too early to determine what Ford has planned for the Mustang’s V-6 and V-8 engines, though we’re guessing the company will be keen to retain the 5.0 badge on its Mustang GT.

We are expecting the 2015 Mustang to be lighter than the model it replaces, so even without significant increases in power, the new car should be a considerably better performer.

Look for a market launch in the summer of 2014, which means we're likely to see the car at the 2014 Detroit Auto Show next January.