I heard from people saying that put your Auto to N while driving will harm your transmission. However, my dad did that all the time but there is no problem yet (the car has been driving for 5 years). I put the gear to N at stops but don't know if it is OK to do it while going downhill.
Any technical explanation? :-)

 

First of all, what is the reason to ever do this? Second, as long as you aren't accelerating while in neutral I don't think it should harm anything, but it doesn't seem like a good idea

 

Neutral will release the torque converter thus the engine is idling by itself. If I just release the gas pedal, engine is still under load. You can test it by looking at the rpm gauge. The reason I did this is that it saves some gas.

 

auto tranny's are tricky the fact that its all computerized gives it more room for error the thing is doing nething that you really shouldnt be doing like constantly shifting it whether your using hte manual shift mode or juss goin to neutral will damage it it just wont show up until way later on....after warrenty expires of course

 

^ learn how to use some punctuation, and the gas you're saving is so finite you would never know the difference.

 

Just because the engine rpm is up doesn't mean it is under load and burning more gas then at idle. It simply means it is a load. If you watch your 0BD reading for throttle position it may surprise you. On some cars coasting will actually close the throttle completely and you will be burning no gas during a coast.

While I used to do this in a couple of spots it was part of a game to see how far I could coast from a set speed at a specific location, a game several of us at work would play. Probably not a good idea on the older cars which sometimes would die when you did this and then you may have some interesting events with power brakes and power steering disappearing.

The biggest issue I see is not putting it in neutral but putting it back in gear, is that good for the power train?

 

the auto will put it self back in the correct gear for your speed. (if your moving when you do this)
the chip won't let you N drop it. (i tried on a loaner)

putting it into N and back in drive won't hurt any thing or save you a noticeable amount of gas.

the only real time u can hurt it is if you rev it up, then put it in gear while the revs are still up. the chip won't engage the clutch packs till the revs fall down a bit, but it will still engage around 2500 or so, which does cause a stress.

 

SAVING SOME GAS ?!
please

 

I did this by accident yesterday.. I always drive in DS and went to up shift on the highway at 60mph and i was in D OPPS LOL just released the gas and put it in D again..

 

^ I do that all the time Lol I try to upshift and forget that I'm in D and I go into N. then my friends think i'm driving a stick and failed to shift into the correct gear lol.

 

Putting the car to N won't do anything, you're still burning gas to keep it at idle the same as if it was in D. Do not put it to N if you are coasting to a stop either, downshifting manually will actually save gas if you keep the revs up high. Once the revs drop below a certain point when coasting to a stop the car starts to take over the wheels and will start putting fuel back into the engine. If you down shift and keep the revs up the computer lets the wheels do the work and you don't burn any fuel. I watch my A/F gauge constantly and whenever I downshift to a stop there is no fuel going through the motor. When you put it to N or keep it in D it will burn fuel.

 

I think on the 'G', at least on the 07 and newer that the engine is always burning gas when it is running during a coast unlike other cars which utilize a fuel injector cutoff during coast.

 

Incorrect. Virtually all modern cars will not burn fuel when coasting down from a high speed. The motor will be driven by the wheels. At a certain point in the RPM range the car will start putting fuel back in, but coming off from say 70mph if you are coasting it will not use any fuel.

 

No.
Just wrong. Automatic Transmissions have been around since far before computers. Fluid controls everything in your transmission. It's basically a series of hydraulic lines and pumps that control a set of planetary gears.

Don't just make stuff up you don't know about.http://auto.howstuffworks.com/automa...ansmission.htm

 

This is a direct quote from an Infiniti tech that I got when setting up an OBD tool for taking onboard readings:

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No the engine is still running the injector pulse is still live. Nissans do not use technology like the Chrysler MDS. We achieve our fuel efficiency with valve overlap, varying intake lift and duration. Timing and fuel injector pulse are controlled and almost cut at some points but they are never off.

S

On Sat, Jun 27, 2009 at 2:10 PM, pfarmer@xxxxx.com> wrote:

S,

Quick question, does the Infiniti shut off the fuel injectors when coasting?

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Since I know this guy as a very knowledgeable tech right to the module design area I trust what he is saying until proven otherwise.

While the engine is possibly driven by the wheels (otherwise maybe not self substaining) I trust that some fuel is still being burned.