Is it wrong to use neutral w/ an automatic?

[Hidden_Hunter]

still waiting for a good reason to do it...

[Lupin_IV]

There isn't a good reason to or not to do it. It's personal preference.

[otispunkmeyer]

i never use nuetral for anything, not even for parking as i usually leave the car in gear (this is on a manual btw)

neutral just shouldnt be used while driving, it gives you the least control over your car

[_HighVoltage_]

It is true what Ottobon said - leaving a newer manual car in gear while decelarating uses NO fuel.

This thread sums up most of the reasons why I don't want to buy an automatic

[thedguy]

Originally Posted by nist7

hmmm, interesting. So does the motor just run on the momentum of the crank/axle ? So combustion is *stopped* since there is no fuel injected into the cylinder?

The 1+ ton moment of the car moving at 30+mph will force the engine to keep moving, the drag from the engine pulling on the closed throttle plate is what causes it to slow down.

Originally Posted by _HighVoltage_

It is true what Ottobon said - leaving a newer manual car in gear while decelarating uses NO fuel.

Yes. Pretty much anything with Electronic Fuel injection will cut fuel on decel. Most engines need to keep the revs above 1300-1500 or their anti-stall will kick in and dump fuel in the engine.

My 1991 miata averages 30mpg when I downshift it and I do a lot of street driving.

This thread sums up most of the reasons why I don't want to buy an automatic

Ditto.

[nist7]

Originally Posted by thedguy

The 1+ ton moment of the car moving at 30+mph will force the engine to keep moving, the drag from the engine pulling on the closed throttle plate is what causes it to slow down.

Saving gas AND saving brakes! Sounds like a good deal to me. But reading about the engine being "forced" to keep moving while drag/friction slows it down....is that "bad" for the engine in anyway?

[Lupin_IV]

It can't be any worse than getting a push start.

[prizrak]

I use N on my auto anytime I stop and don't turn off the engine. I don't like using P as it feels like the car is actually doing more work that way. You can easily run the tranny in N even while driving the only thing is make sure you use the throttle to rev match to w/e speed your tires are going when shifting back into D otherwise you will do the equivalent of dumping a clutch at the wrong revs, the only difference is that unlike the clutch the TC has no way to slip, same goes for building up RPMs in N and taking off. Great way to fuck up your tranny.

[Twerp128]

The biggest danger I see is accidentally shifting into Reverse or Park while on the move.

[thedguy]

Originally Posted by nist7

Saving gas AND saving brakes! Sounds like a good deal to me.

But eats up your clutch faster and/or your syncros in your tranny. Gas and brake pads are far easier to change than either of those.

But reading about the engine being "forced" to keep moving while drag/friction slows it down....is that "bad" for the engine in anyway?

It's fine, the engine isn't being spun backwards or anything. It's likely EASIER on the engine as you don't have a bunch of small explosions happening. Anytime you start the engine your doing the same thing, or whenever you downshift (racers do it how many times a race?)

[Spectre]

Um, there's no difference between P and N except that a parking pawl is shoved into the gears in P. So I don't know why you'd say your engine is working harder in P.

[Crazyjeeper]

Originally Posted by thedguy

But eats up your clutch faster and/or your syncros in your tranny. Gas and brake pads are far easier to change than either of those.

If you downshift and match revs (like me), the it does not eat your clutch/syncros nearly as much, and you get the same free deceleration.

[tigger]

I don't know why the hell you'd do that, but you're not hurting anything either; so long as the engine is running.

[prizrak]

Originally Posted by Twerp128

The biggest danger I see is accidentally shifting into Reverse or Park while on the move.

Depending on speed it won't do anything, I've accidentally done it before and nothing will happen basically.

Um, there's no difference between P and N except that a parking pawl is shoved into the gears in P. So I don't know why you'd say your engine is working harder in P.

If you have an auto try it out for yourself In P the engine feels like it does in D while brakes are applied in N it feels like there is no load on the engine at all. It's hard to explain but the vibration feels different through the body of the car in P and in N with brakes applied.

[Zuhaib]

Originally Posted by prizrak

Depending on speed it won't do anything, I've accidentally done it before and nothing will happen basically.

If you have an auto try it out for yourself In P the engine feels like it does in D while brakes are applied in N it feels like there is no load on the engine at all. It's hard to explain but the vibration feels different through the body of the car in P and in N with brakes applied.

Well first it will do something, you can screw up parking pawl as it will try to stop the car. And putting it in reverse while moving froward can also cause a whole host of issues. Once or twice its ok, but, you cant say "nothing" will happen.

As for the "feel" vs load on the engine. You might have a lot of vibration in park due to some other issues (I bet others can give input in to that) but I doubt it cause a lot of load on the engine itself.

[Spectre]

P causes no more load than it does in N. I have three automatics here and NONE of them do anything different in P than they do in N with the brakes applied.

If your car is shuddering while in park and it doesn't in neutral, there's something wrong with it.

[prizrak]

Originally Posted by Spectre

P causes no more load than it does in N. I have three automatics here and NONE of them do anything different in P than they do in N with the brakes applied.

If your car is shuddering while in park and it doesn't in neutral, there's something wrong with it.

Hmm different gear box designs then? I've experienced the same thing in all the auto's I've driven (about 3 that I can remember reliably). It doesn't shudder but it just feels like it does in D with brakes.

[Spectre]

Um, not likely. I've got a Borg Warner M66, a GM 4L80E and a Nissan RE4R01A. None of them do what you describe, and their modes of operation are all different.

I think you are severely mistaken in your perception.

[prizrak]

Originally Posted by Spectre

Um, not likely. I've got a Borg Warner M66, a GM 4L80E and a Nissan RE4R01A. None of them do what you describe, and their modes of operation are all different.

I think you are severely mistaken in your perception.

Well if my tranny falls out we'll know