CVT RPM's at Idle

[snwbrdraw]

I know this is splitting hairs (or more accurately splitting dashes) but I've noticed that I get a lower RPM when at a complete stop and idling in the D gear than I do in N.

Granted, both are below 1,000 but D brings me a full tick below N on the stock gauge. I was wondering if...

Anyone else noticed this?Anyone else who has a standard AT rather than CVT notice any difference?What, if any, predicted MPG boost will I get from idling in D vs N since it's a lower RPM?

...things you notice when you sit in bumper to bumper traffic everyday for 30+ miles.

[matt_a]

When and why would you ever sit and idle in "N" with an automatic or CVT? If I'm stopped at a light or in traffic, I'm going to be in "D" with my foot on the break. If I'm stopped for too long, I'll go to "P", but never "N".On a side note.... I did notice that with our CVT, at 70 MPH it's only at 2,200 RPMs!

[snwbrdraw]

When and why would you ever sit and idle in "N" with an automatic or CVT?

I've been doing a lot of reading on the concept of "Hypermiling" to save MPG and one of the chief principles is to switch from D to N whenever possible to immediately drop your RPM's and use your momentum as long as possible; especially if you are on your way to a stop at a light of traffic. It works much better with a Manual, especially if you undershoot and have to go back in gear before stopping, but AT's can also use this to their advantage to save gas.

Once you get the hang of the Neutral Shift, they also recommend you shut your car off completely to further reduce gas consumption. Not sure I am going this far as the loss of power steering and brakes doesn't sit well with me.

Anyone else a Hypermiler?

http://www.hypermiling.com/

http://www.cleanmpg.com/forums....html

[matt_a]

Personally, I'd be more worried about wear-n-tear on the car too. All that shifiting in and out of drive, and all that starting and stoping the engine seems to me like it would be hard on the car.

[coxcj]

I'm not so sure about the wear and tear on the car. I used to drive a 5M jetta, and I did that all the time. The only concern I have is that the CVT has such a hard shift into gear from neutral, so I would think that it's not that good of an idea.

I'd like to see some test results to know how the CVT would do after prolonged activity like that. (at this point I'm not willing to subject my new baby to the challenge).

[matt_a]

I'm not so sure about the wear and tear on the car. I used to drive a 5M jetta, and I did that all the time. The only concern I have is that the CVT has such a hard shift into gear from neutral, so I would think that it's not that good of an idea.

I'd like to see some test results to know how the CVT would do after prolonged activity like that. (at this point I'm not willing to subject my new baby to the challenge).

Exactly. I also can't help but think that it's a little hard on a car to be constantly shutting the engine off and restarting it.

[Eastval1]

Once you get the hang of the Neutral Shift, they also recommend you shut your car off completely to further reduce gas consumption. Not sure I am going this far as the loss of power steering and brakes doesn't sit well with me.

This won't work for you anyway. Hypermilers shut off their engines at highway speed (they're not talking about shutting down at red lights when you're safely stopped). They do this and then coast as much as possible while drifting behind semis. You can't do this with an automatic, and it can be very tricky with a manual. Most automatics can't be shut off and turned back on at that kind of speed without significant damage.

[KimberKenobi]

they also recommend you shut your car off completely to further reduce gas consumption. Not sure I am going this far as the loss of power steering and brakes doesn't sit well with me.

When I drove stick, I could shut off the engine but retain my power steering and breaks as long as the accessories were on... You might could try that and see if it'd work on the V... mind, I only did this on the steep downhills when you'd be going for awhile, starting up is a strain on components too...

[bigdog]

reason y rpms r lower n drive than nutral is due to having a load on the engin while n drive. does that answer your question about rpms

[snwbrdraw]

Thanks for all your insights. I've been trying the N shift for the past week and am half-way through a tank. I'll see what kind of results I get and post them if anyone is still interested.

I do have to admit I am little worried about the CVT as it is VERY jerky when going back into D from anything other than a complete stop. Even then, I'm not sure if it is meant to shift that much. Maybe I should have gotten the MT...

[biggie]

The CVT would not know what position the pulleys need to be in when coasting in N, they probably drop to the starting position like if you were stopped. This could definately lead to some transmission issues down the road.

[Ever Victorious]

Indeed. This is similar to what happens when you panic-stop a CVT. The transmission slips for a few minutes afterwards because it gets horribly confused as to where the pulleys are supposed to be configured, and it takes it a while to reconfigure, recalculate, and reposition.

There was even one story on here a few months back about someone whose CVT simply wouldn't go after a panic stop, and they had to get it towed to the dealer!

I would not reccommend taking a CVT out of Drive, except to put it in Park or Reverse.