I was just teasing but the point is well taken about the vehicle idle overhead considering:
- electric power steering - instead of a mechanical hydraulic pump
- electric assisted braking - instead of a manifold vacuum and bellows
- electric air conditioner compressor - instead of belt driven
- electric water pump - instead of belt driven
Each of these loads will have peak values but even my 2003, NHW11 with daylight running lights on draws ~1.6A @275 V ~= 440 W. (the amps vary.) I haven't tried to measure the ZVW30, engine off load, yet, but from what I've seen of the systems, I suspect it is in the same range.
So putting things in perspective, the rule of thumb I use is ~250 wHr/mile for most vehicles. In an hour, the Prius idle electrical load would be almost 2 miles of travel. But I would caution that the additional load of power steering, braking, air conditioner and intermittent water pump could easily dwarf the idle overhead. A vehicle designer might see these as predominant and not think of the idle overhead as being significant.
Bob Wilson