I have a few general car questions.

1. Does it save gas to put the car in neutral when coasting and at stop lights?

i doubt it. your car is still gonna be on. you may go down like 200 rpms, but that wouldn't be saving that much gas.

2. Is it safe (if you keep your foot on the brake)? Is it safe to turn the car off at a light?

shouldn't the car shut off anyway?

3. What help and damage could it be for the trans. to be changed to neutral and back to drive?

i doubt it would help and i don't know if it would do any damage. i don't know anything about transmissions.

4. Overall, is it a good or bad idea to put an auto. in neutral in any of these cases.

i don't think it would hurt the transmission, but over time, it may wear it down quite a bit.



those are just my thoughts, if i'm wrong let me know.

No need to play with the shifter

I have a 2002 CVT Insight and don't see any reason to shift into neutral as you suggest. If your temp. control is in ECON or OFF the Insight will cut the fuel supply and ignition during braking and the engine will turn off below 5 mph. If I remember correctly, shifting into neutral will not allow the engine to turn off below 5 mph or when stopped. My recommendation is to review your owner's manual to find out more about the criteria that need to be met before the Autostop feature will function. Also, whenever I come to a stop when parking and the engine shuts off (autostop) I first turn off the ignition, shift into park, turn the key to the lock position and remove it. This prevents the engine from restarting unnecessarily when I'm parking the car. I can't think of any reason why this would have an adverse effect on the Insight. I hope this helps answer your question(s).

On any general car I woulnd't recommend any of the above. You *might* save some gas by shifting to neutral comming in to a light, but for the little bit of fuel you might save, as the car will idle anyways, is not worth the extra stress on the tranmission you get from shifting in and out of gear. Thats what the torque converter is for. I don't know all the specifics, but shifting in and out of gear a lot stresses the components.

As far as turning a car off at a light, I have done this before but it was because the piece of junk I got stuck driving was overheating and letting it idle would have ment being stranded. In general shutting a car off at a light is a bad idea. Not engine wise, but it would put a hell of a stres on the starter. Starter motors are wound to move many amps for a bried period of time to crank over and engine and thats it, continual operation will lead to a very quick failure of one. In fact I think most are rated for abotu 15 seconds of operation every hour, and with any car it's recommended you don't let it crank for over 15 seconds at a time.

On our Insight's the large IMA motor is used to restart the engine from a stop. Not only is it designed to do this, but has enough power to get it up to speed in short order.

Your best bet is to just let the car do what it was supposed to do. Sorry, it's not designed to turn on and off like that. The only time where you would get much gain from shifting to neutral would be to coast down a long hill so that you wouldn't be using the engine for a compression brake. Doing so would disengage the transmission from the engine and would cause it's rmp to lower (fuel savings). Just be careful you don't throw it in to reverse, some vehicles will actually engage at speed. And this would only be on a highway trip that I would bother with it if it was a long hill.

Believe me, be nice to the tranmission. I've blown up two.

FinalHeven said:

These questions are for any automatic trans.: 1. Does it save gas to put the car in neutral when coasting and at stop lights? 2. Is it safe (if you keep your foot on the brake)? Is it safe to turn the car off at a light? 3. What help and damage could it be for the trans. to be changed to neutral and back to drive? 4. Overall, is it a good or bad idea to put an auto. in neutral in any of these cases.

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i will answer this for the CVT Insight (sorry if i'm off topic now)

1. NO. while coasting (foot off the accelerator pedal) the Insight enters Fuel Cut mode in Drive (pistons still moving, but not getting gas). If you put it in Neutral, you can coast farther, but your engine will now need to use gas to idle - preventing it from stalling.

2. If you are in Auto-Stop mode, turning the key off will turn off the rest of the car (electrical appliances). This may save you some battery charge if you are stopped for a long time, but make sure you put the car into Park when you turn it on again!
If you are stopped and your car is idling, you could put it in Park and turn off the car. I have done this when traffic is standing still for several minutes.

3. In my previous Automatic transmission cars (Nissan Pathfinder and Honda Civic), putting it into Neutral seems to tell the transmission there is no load on the engine, so it will shift into 1st gear; if you are still moving, and you put it into Drive again, hold on to your butt!
I have not tried this in the Insight (yet :twisted: ).
I have done something I think is similar: accelerated on a hill with Auto-Stop engaged; what basically happened was the transmission stayed in a low gear when it turned off at 6mph, and when it turned on at 25mph, I nearly hit my head on the windshield!

4. I sometimes put the car in Neutral in the drive-through, when Auto-Stop will not engine, and the rough idle in Drive starts to erk me.

hope this helps (for someone )