Engine Effeciency Over Speed Curves

[Natustell]

Does anyone know where to find efficiency over speed curves for Ford's engines? I am specifically interested in the SOHC V6 4.0L engine used in the 2003 Ford Ranger.

Example of what I am talking about (green line only):

 

[Uncle Gump]

Are you from this planet?

 

[DILLARD000]

Must be an Electrical\Mechanical Engineer? Pretty much same as an ExtraTerrestrialAlien
Curves commonly available for ElectricMotors; for an engine, data produced on a Dyno.
Published Engine Ratings for the stock V6~4.0L~SOHC; click the link for a curve:
205~210hp 151~155kw @5000~5250rpm
238~254ftLb 322~344nm @3000~3750rpm
Personally agree with above numbers: "Kick in The Pants" seems to max out above 3500rpms.
Guessing efficiency would be FuelConsumption? Not good, considering they rarely get >18mpg.

PS:
Welcome to the Herd!
Lots of friendly knowledgable folk in these forums.