> The Toyota HSD runs the engine at one of two pre-determined speeds (not
> counting "off") Its the same basic idea he described. The reason that it
> can do so is that the road speed is basically the sum of the engine
> speed and motor/generator speed, so that road speed can vary without
> changing the engine speed over a certain range, by changing the speed of
> the M/G. When the road speed gets high enough, the engine kicks up to
> its higher speed.
The Toyota has a CVT. That is the operative technology, not the
hybrid technology.
Hybrid technologies that implicate constant-velocity engines are those
like locomotives where the engine spins at a constant speed to power a
generator which drives motors at the wheels.
Trav
