Neutral to drive?

[Rick Rae]

Originally Posted by popimp

I'll have to disagree.

You'll have to disagree with... what, precisely?

The point is don't take the Scan Gauge's word as gospel. The true numbers are in the fill up.

Scan Gauge wasn't mentioned at all in that message. And I agree that actual consumption is what matters.

Rick

[popimp]

Originally Posted by Rick Rae

You'll have to disagree with... what, precisely?


Scan Gauge wasn't mentioned at all in that message. And I agree that actual consumption is what matters.

Rick

Disagree that most of the savings are from the Neutral glide. Although each vehicle will yield different results.

[Rick Rae]

Originally Posted by popimp

Disagree that most of the savings are from the Neutral glide. Although each vehicle will yield different results.

Thanks for the clarification. Your post seemed focused on the inaccuracy of the numbers you got from your Scan Gauge, so I wasn't sure what you were getting at.

Feel free to post your EOC figures to contrast with the neutral coasts. Unfortunately, driving an automatic as I am, I can't safely explore that area.

Also, don't hesitate to run the numbers using your actual fuel consumption and achievable coast percentages and post your results. What I gave was an example, and while I think it's a realistic (if optimistic) one, it'd be nice to see some real-world figures.

Rick

[Scott_in_Tulsa]

I just finished my first tank that included as much neutral coasting time as possible. This of course was with the engine running. I did manage to squeeze out 35 mpg and probably only did a neutral coast over 10% of the mileage driven.

I don't have a Scan guage or anything to help me monitor this performance other than the stock RPM gauge and keeping a keen ear to the sound of the engine. I have found that I can drop my RPMs from 2000 RPM in drive with my foot completely off the gas to about 800 - 1000 RPM in a running neutral coast.

I think this can be a huge benefit depending on the vehicle weight. The last two days I have been driving in rain and snow and added 100 lbs to my trunk for a little extra stability. The weight of course negatively affects my overall fuel mileage but I have noticed a positive in my coasting distance with the added weight. Not sure, but it may help balance out the fuel economy if I am able to coast enough with the added weight. Of course, the weight is coming out as soon as the weather improves.

[8307c4]

I'm not saying you can not do it, but I am saying for transmission longevity I recommend leave it in D always, also I am saying if you shift it you do so at your own risk.

Here's the thing, even if the chances of breaking it are but 1 in a million...
Who has to pay for it if (or when) it breaks?
You think one of these hot shot shift pros here are going to spring for it?
Personally I think you have to pay for it, if it breaks.

Yes, it can go flawlessly hundreds if not thousands of times.
All it takes is one time, one mistake, one bad luck moment.
What slowed me down is the price of a rebuild, and the fact most transmission specialists say the same thing: You want fail-safe operation then leave it in D.

That having been said, I do coast in N.
Hahaha but I have to say these things, I don't want nobody crying the blues if their tranny craps out for any reason.

Originally Posted by Bruce

Don't push the shift lock button (or pull forward on a column shift) when shifting between Neutral and Drive. This will prevent accidental shifts into Park, Reverse or the Low range. Just push the shifter back and forth.

Better yet, spend some time playing with the shift lock button and lever positions while the car is parked with the engine off to understand how it works. You should only need to depress the shift lock button to shift out of Park or to shift into Reverse, Park or the Low gears.

Until it malfunctions, or I shift so fast the detent mechanism fails to engage properly thus overriding the stop between N and R. Sometimes they break, sometimes they don't work like they should, my oldest car I can shift to-from any gear any time, doesn't matter when, how, or where.

Also column shifters work different from a floor shifter, but either one...

[tomatoman]

Has anyone tried something as simple as a drivers compartment switch to electronically cut out fuel injectors at the top of a hill, effectively shutting off gas completely while leaving the transmission engaged?
The idea just struck me.
It should be a very simple idea to test.
T man
33.15 mph 94 Maxima AT, fuel cocktail, see "garage"

[kamesama980]

Originally Posted by tomatoman

Has anyone tried something as simple as a drivers compartment switch to electronically cut out fuel injectors at the top of a hill, effectively shutting off gas completely while leaving the transmission engaged?
The idea just struck me.
It should be a very simple idea to test.
T man
33.15 mph 94 Maxima AT, fuel cocktail, see "garage"

yes, search. also look under coasting with an auto trans with the engine off blowing up the trans threads.

[malherbe]

I maximize coasting to great benifit. I have a 99 vw passat 4c rated at 21 and 31. I regularly get 22 -28 by coasting. This is verified at the pump. It is true that the computer will read higher mpg's going down hills if left in drive, but i can go much farther and faster in nuetral. My car does have the fuel shut-off feature, and i never shut the car off while coasting. driving down hill in gear is like driving with the brakes on.

[dosco]

After looking at the SFC charts, I'm not convinced the savings are in the glide.

I am under the impression that the economy comes from maximizing the engine's operation at a certain BMEP and RPM range.

EDIT: After further consideration, I retract this comment. Brain fart, y'know.

[MarvHein]

I became a believer in neutral coasting with my Yukon XL, pulling my mostly city driving mpg up approx. 2 mpg.

Coincidentally (or not) my front diff threw a bearing and ate itself into total replacement. The tranny still seems fine and shifting back into gear after a glide has always been smooth.

Is there any way neutral glides technique could have damaged the front diff?