Ecometer Usage

[KrazyDawg]

Recently I've purchased an Ecometer and I've been wondering on how to maximize its usage, especially when it comes to accelerating without a tachometer. I tend to overanalyze things and broke down the Ecometer into the four modes it represents. My target mode is 40 MPG.

Instantaneous MPG
MPG will fluctuate greatly but can assist the user in finding the best speed and pedal pressure to maintain the high MPG over a specific point in the road/highway. For example, driving on the highway at 70 MPH my MPG will jump around from high 30s to the low 70s. DFCO will push it higher and I've seen over 200 at the most for me.

Average MPG
This seems like the mode most users would use since it corresponds with the MPG calculated from a complete fill-up. I've noticed my MPG drop from 38 to 35 after driving in the city. Waiting at a traffic light, I dropped nearly 1 MPG.

Speedometer
I don't think this mode is used often but you can attempt to match your MPG to the speed you're driving at given the road conditions e.g. speed limit, hills, etc.

RPM
Since the tachometer is an option, this mode might help in accelerating from a stop sign or traffic light. I read that the magic number is 1500rpm ?

To all Ecometer owners, which mode do you frequently use?