Impossible to tell from a desktop.
For example, a particular platform was available in Oz that had everything from a 1.9L 4 to a 5l V-8, and I owned botht the top and bottom aend, and most of the middle at various times. On the highway, all of them returned the same (within 1MPG) mileage.
In your case, the engine is loaded, at low RPM you will have the throttles far more open, and have better cylinder filling and theoretical efficiency, and lower frictional losses...that's why they do it.
Drop a gear, the revs go up, presumably at a lighter throttle (power equals torquexRPM, so more RPM, lower torque, more throttling), and should therefore have lower efficincy, and higher frictional losses...not much difference., but probably more fuel.
For example, a particular platform was available in Oz that had everything from a 1.9L 4 to a 5l V-8, and I owned botht the top and bottom aend, and most of the middle at various times. On the highway, all of them returned the same (within 1MPG) mileage.
In your case, the engine is loaded, at low RPM you will have the throttles far more open, and have better cylinder filling and theoretical efficiency, and lower frictional losses...that's why they do it.
Drop a gear, the revs go up, presumably at a lighter throttle (power equals torquexRPM, so more RPM, lower torque, more throttling), and should therefore have lower efficincy, and higher frictional losses...not much difference., but probably more fuel.