Thanks for the info. Bar, I recall reading that too- I think that one is not correct. Any V6 engine can get well over 25 instantaneous even normally- dunno why Honda would set the 'eco' bar so low.

Then notice that the Honda statement Drourke dug up (thanks) is an "and" condition. Both need to be met for eco to come on. Press releases are worded very specifically for legal reasons; its unlikely they conveyed inaccurate information.

Dale- You may be feeling the torque converter locking up (around 48) and VTEC changing timing, generating extra power that you feel as an impluse? And there is a little latency between the light and the 3cyl nudge I feel, especially when I'm on-off-on-off.

Of course, you could all also be correct and I am simply wrong. What we need here is a real Honda guy to weigh in. At any rate, I feel its still pretty safe to say that for most intents and purposes, "eco" = 3 cylinders, especially when explaining to others. There, I caveated myself.

edit:
On second thought, after writing my ethanol post and commenting on the unwillingness of eco to come on, maybe there is a minimum MPG 'interlock' that has to be met...