Hmmmm, how exactly are y'all achieving the 55+ kW rates?
For example, when I get off the Interstate at the exit I use most frequently, one crests a hill and in my ICE vehicles, I just cancel cruise and still have to brake strongly at the bottom about a mile from the crest.
In my Volt, I'll cancel the cruise and if nobody is behind me, I'll drop it into Low at 70 MPH and still have to brake halfway down the off ramp. In this scenario, I will see 12 - 15 kW peaks before touching the brakes and increasing to 14 - 17 kW while braking. I think I saw it hit 18 but I have never seen a number of 20 kW or greater.
I'm basing this on the "Engine" graphs in the main instrument cluster / LCD with the bars at go up in yellow and down in green. I have MyGreenVolt but have not compared those values.
Added: From a topo map, I estimate the elevation drop about 55 feet from the crest to the traffic signal at the bottom of the exit ramp... not exactly a mountain but still a hill nevertheless.