Robb S via CarKB.com did pass the time by typing:
> LOL I understand that, but fortunately I don't live in california. I
> have a friend who posted that question, and a co-worker told him that if he
> put his tranny in neutral, and coasted down a hill, and then put it back into
> drive at the bottom, it would harm his tranny.........sounds reasonable, but
> I told him to type his question here, to hear what the experts have to say....

The engine is still turning the tranny vs towing so no damage will occur.

What will happen is the vehicle suspension becomes unloaded and hard to control.
Small bumps will now cause great swings in the suspension and that's why it's
illegal to drive like that. Heck, if the hill is that steep the vehicle will
coast in gear anyway and using the engine to keep speed in control is easier
on your vehicle than riding the brakes.

--
DougW