I assume no regen takes place when braking in N because I don't see any arrows and the brakes feel different (smoother) and you don't hear the WRRR of the motor like you do under regen. Also, when in N and at a dead stop (ICE off), stomping on the accelerator does absolutely nothing. No ICE startup or rev at all. This indicates that the ICE most likely is cut when the wheels are moving, at any speed?

The easiest way to test all this is for someone with a ScanGauge to investigate!

After reading all the replies on this thread and the new one about Heretical mode (and fuel-cut?!! need to get me a scangauge!), I've been driving by the MPG meter instead of the spedo, and getting 45-50mpg (instant) for highway stretches doing 65-75mph!