It is my understanding that older AT's had two pumps, one driven off the output shaft, the other from the input shaft.

Now, I believe, they have only the front pump. Thus towing without the engine running for any significant distance will result in damage.

As to coasting, gas savings are iffy, but perhaps measurable. With the engine running, even at idle, the front pump is running and ATF circulating so there should be no damage.

The safety considerations are of most importance. It's a judgement call.

I, too, coast, but for other reasons. I have noticed that braking effect is better when approaching a stop. As from 30mph to zero. Then back to "D" while awaiting the green light.

Pass this to your friend.

Regards,

Bob

:>)