Ecoboost engine question

I personally think that for ecoboost motors to return the fuel economy they tout, they must stay out of boost. My personal experience was with my 07 saturn sky redline. That car was rated at 29mpg freeway. However, if you could stay out of boost, I was able to eek out 34mpg. If you put the ecoboost in a heavier rig like the F250 and higher, the heavier chassis and possibly increased drag of components and aerodynamics (as far as I know, Ford hasn't put much Aero effort into its HD trucks) would more than likely keep the turbo's spooled or closer to being spooled. For a gas motor, this would actually decrease efficiency. The more time an engine can spend off of turbo (acting like a naturally aspirated motor of its displacement) and provide enough thrust to maintain speed or perform modest acceleration, the more fuel saving the motor is. The idea of the high horsepower and torque rating on the ecoboost is that the power and torque would only be needed for heavy loads and acceleration. From many rags like pickuptrucks.com, there isn't any gain in towing fuel economy in ecoboost vs. 5.0 v8 (some reported a slight detriment in mpg). However unloaded the ecoboost shines as it doesn't need to dip into boost for daily driving unless the driver feels like having some "Fun". Putting the motor in a superduty would be like towing a small weight at all times and diminishing the ability of the 3.5 to save fuel over the 6.2.

Basically turbocharging is just another method of displacement-on-demand. For every 14.7 psi of boost, you've added another engine of the same size. Only thing bad about turbocharging is that you do need to run a little richer than 14:1 afr. Even with direct injection (though with old-school port injection you needed to maintain 11:1 afr, I beleive the dip is only down to 12.5 or 13:1 for gasoline direct injection).