Fusion ST Engine
It's all but assured that the Fusion ST will use an EcoBoost engine - most likely the 2.3L that's found in the Lincoln MKC and Ford Mustang. The 2.3L utilizes a single turbo.
While the 3.5L EcoBoost is probably too much for the Fusion - in terms of necessity, an interesting alternative would be the 2.7L Ecoboost found currently in the Ford F150. Although only marginally larger in size than the 2.3L EB, the 2.7L engine uses two turbo chargers - hmmmmm.
Of course, there's the difference of weight to consider though. The 2.3L is a four-cylinder while the 2.7L is a heavier, V6.
What are your thoughts?