While I love the idea of an ecoboost 6.2 (or bigger) it's unfortunately very unlikely to ever happen with CAFE standards what they are, but just for fun I've taken the list of Ecoboost engines from Wikipedia and plotted the displacement vs horsepower and extrapolated a line to 6+ liters. I like the looks of what I'm seeing

 

Nice work on that graph. I doubt they'd have a truly linear relationship, it'll probably flatten out some, but still, awesome thinking.

 

Yeah, you can see that happening since the 3.5 in top form is 108 HP/liter compared to the 150 HP/liter from the 2.0 in the Focus ST. If they could maintain 100 HP/liter though even at 6.2 liters, it'd still be 620 HP and probably 700+ lb/ft of torque.

 

The 2013 Shelby gets 662 hp with 5.8l. I'd say the 6.2 could at least do that.

 

Keep in mind car engines are tuned differently than truck engines. The 5.0l in the Mustang makes 420hp @ 6500rpm and 390ft-lbs tq @ 4250. The 5.0l in the F150 makes 360hp @ 5,500rpms and 380 ft-lbs @ 4250rpm.

Then one has to keep in mind the 6.2L is a 2v SOHC engine vs the 5.8L being a 4v DOHC engine.

If Ford did an Ecoboost version of the current 6.2L for the F150 I wouldn't count on it matching the horsepower of the Shelby.

That being said, I wouldn't expect a 6.2l ecoboost at all from Ford. Supposedly the nose on the new F150 isn't large enough to properly accommodate the 6.2L.