Pulse and Glide with the engine running?

[DRW]

Here's another good post to illustrate peak vs poor efficiency. http://www.gassavers.org/showpost.ph...8&postcount=46
Be sure to click on the map and notice how quickly efficiency drops off as load gets lighter approaching idle load. Notice how efficiency is best around 2k to 3k rpm and 50% to 75% load. This is why traditional P+G works so well.
Granted, a vehicle with lean burn capability has different efficiency islands, as leaner A/F ratios are used at light load, which helps reduce the inefficiency of running at light load.