Momentum driving on neutral gear to save on gas

What damage am I inflicting to the 06 Dodge Caravan (AT) if I put on neutral gear while driving on a slightly downhill road?

Very little, but what do you expect to gain?
In gear going down hill, all fuel to the engine is shut off.
In neutral going down hill, the engine requires fuel to maintain idle.

If you do this routinely you’ll put a bit more wear on the transmission linkage. That’s all.

But if for some odd reason you suddenly need to accelerate for an unexpected avoidance maneuver you’ll be screwed…

Thnx for reply. I see cars/SUVs towed behind RVs in free ways. Aren’t the towed vehicles on neutral gear as well? What’s the difference in gas consumption between a car on neutral gear and another in gear, assuming both in transit? We drive around mostly in a quiet neighborhood, so i’m thinking there’d be some gas savings when driving on momentum/neutral gear especially when slowing down for a red light. Can you share your thoughts on this?

Towed cars don’t generally have their engines running.

You may save a little, you may actually use more gas (fuel injection often shuts off while coasting in gear, but not in neutral). But one mistake and you’re in trouble (missed shift, needed gas when you’re in neutral). Not at all worth the trouble.

The cars towed behind RV’s should have manual transmissions. An automatic transmission car needs to have the drive wheels off the ground when towed. If you don’t lift the wheels the damage to an automatic transmission is severe.

Others have given good reasons not to coast in neutral with an auto transmission. Another reason is in moving from D to N you might overshoot and put it in R. Engaging reverse when moving forward is a very exciting event and your transmission won’t be at all happy. It may just require a rebuild to make sure the dollars of pain inflicted is enough so you’ll not make the same mistake again.

With all these silly posts on this subject I did a little test
STOPPED and in neutral my truck idles at 600 rpm.
While driving at 75 mph @ 2500 rpm, I put it in neutral…2300 rpm… NOT IDLE rpm.

Don’t trouble yourself.

Unless your vehicle can prove itself out. Do the test for yourself to see if you get IDLE rpm at highway speed in neutral.

Ken, I am curious, what rpm does it have at 75 mph if you let off the gas leaving it in Drive??