Originally Posted by Tom K.
I've found the most economical lower gear upshift points to be around the torque peak of 2750 rpm.
But until the OP gets a feel for how his engine and transmission are interacting, light throttle in D is probably his best bet.
A lot depends on the acceleration rate, as peak torque is measured at WOT. There wll be a much wider range of rpm where sufficient torque will be available for part throttle acceleration, say at 1/4 or 1/2 throttle acceleration. You want the slowest rpm where maximum mpg is obtained, also parasitic and frictional losses are at lowest values.
A part throttle torque graph/map would be very useful to see where change points are most suited.