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Nissan Car Lounge - Almera, Juke, Latio, Qashqai, Sylphy, Teana Owners => Latio => Topic started by: rodrigue on May 11, 2008, 10:39:58 PM

Title: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: rodrigue on May 11, 2008, 10:39:58 PM
hey pple, i heard n read abt the above mentioned. is tat true?
thks  :smile:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: CustomGolf on May 11, 2008, 10:49:16 PM
Bro, if you're not at a traffic junction waiting for the lights to turn green, your engine should be off so it doesn't really matter if it's at neutral or not, just that you won't be able to start your ride later if your gear is engaged. If you're at the traffic junction, how long is the wait? How much can you save?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: idiotboi89 on May 11, 2008, 10:54:31 PM
dont know about netural but parking the rpm idles at 800, i put D step brake idles at 600 or so.  :D
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: Jazz on May 11, 2008, 11:47:00 PM
dont know about netural but parking the rpm idles at 800, i put D step brake idles at 600 or so.  :D

Theoritically is the same, idle mode, free wheel therefore is 800rpm, but when engage to D, driver is rotationg with a force coz driven is stopped by our power brakes.  :smile:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: HumbleCar on May 12, 2008, 08:41:16 PM
hey pple, i heard n read abt the above mentioned. is tat true?
thks  :smile:

Answer is in last week's free issue of the CarBuyerGuide.
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: idiotboi89 on May 12, 2008, 09:04:17 PM
Theoritically is the same, idle mode, free wheel therefore is 800rpm, but when engage to D, driver is rotationg with a force coz driven is stopped by our power brakes.  :smile:

weird i thought stepping brakes they disengage or something, if not sure damage something right?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: ckyc on May 12, 2008, 10:17:14 PM
I also tot of this.. perhaps can save a penny, but later gear box spoil ... then not worth liao
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: rodrigue on May 12, 2008, 10:38:35 PM
Answer is in last week's free issue of the CarBuyerGuide.

oh okies... thks alot for ur views..  :smile:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: hope_n_pray on May 12, 2008, 10:40:35 PM
Answer is in last week's free issue of the CarBuyerGuide.

I didn't manage to get my hands on it. So what's the answer?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: Jazz on May 12, 2008, 10:54:06 PM
weird i thought stepping brakes they disengage or something, if not sure damage something right?

Obviously you do not know how an automatic gear works.  :D

MT is using clutch and gear, when you step the clutch, it disengage, but driver still turning.

AT is by fluids, that is why when you let go brakes, it moves. Nothing is being damage. Go read up more and you will understand.  :thumbsup:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: Jazz on May 12, 2008, 10:57:30 PM
I also tot of this.. perhaps can save a penny, but later gear box spoil ... then not worth liao

This is called penny wise, pound foolish.  :D
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: HumbleCar on May 12, 2008, 11:08:11 PM
I didn't manage to get my hands on it. So what's the answer?

Based on my understanding of Question 76 which says something about coasting in neutral vs in gear.  The logic is the same for stop vs coasting.  The real question is whether fuel supply will be cut off in order to save fuel.

The text is ".......Modern fuel injection engines cut off the fuel supply to the cylinders when you lift your foot off the accelerator pedal, BUT ONLY IF THE CAR IS IN GEAR."

(Please note words in CAP.  Hence, if the car is not in gear, the fuel supply will not be cut off.  Think quite a number of ppl (myself included) think that engaging neutral and let the car roll slowly towards the traffic red light saves fuel.  The above text says otherwise.)
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: rodrigue on May 12, 2008, 11:17:41 PM
Based on my understanding of Question 76 which says something about coasting in neutral vs in gear.  The logic is the same for stop vs coasting.  The real question is whether fuel supply will be cut off in order to save fuel.

The text is ".......Modern fuel injection engines cut off the fuel supply to the cylinders when you lift your foot off the accelerator pedal, BUT ONLY IF THE CAR IS IN GEAR."

(Please note words in CAP.  Hence, if the car is not in gear, the fuel supply will not be cut off.  Think quite a number of ppl (myself included) think that engaging neutral and let the car roll slowly towards the traffic red light saves fuel.  The above text says otherwise.)

haha bro.. thks for typing the whole thing out.. i bet ours must be modern fuel injection engines.. think your answer clears all my doubts.. arigato!  ;D
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: HumbleCar on May 12, 2008, 11:21:51 PM
haha bro.. thks for typing the whole thing out.. i bet ours must be modern fuel injection engines.. think your answer clears all my doubts.. arigato!  ;D
No problem, bro.  Just copy type only.  Not I draft, hehehe. 
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: idiotboi89 on May 12, 2008, 11:29:53 PM
Obviously you do not know how an automatic gear works.  :D

MT is using clutch and gear, when you step the clutch, it disengage, but driver still turning.

AT is by fluids, that is why when you let go brakes, it moves. Nothing is being damage. Go read up more and you will understand.  :thumbsup:

ahha always thought its like manual, i step brakes, auto clutch in or something. no wonder got ATF..  :devil2: will go read up
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: rodrigue on May 12, 2008, 11:35:37 PM
this piece of info is something good to share with newbies... agree?  :yehyeh:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: Jazz on May 12, 2008, 11:43:20 PM
ahha always thought its like manual, i step brakes, auto clutch in or something. no wonder got ATF..  :devil2: will go read up

Yep, no worry, everybody is learning everyday.  :D
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: detach8 on June 03, 2008, 11:19:18 AM
yeap i think howstuffworks has a very good article on torque converter (the clutch equiv in AT gearboxes), read that.  :thumbsup:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: xuan511 on June 03, 2008, 01:50:48 PM
ahha always thought its like manual, i step brakes, auto clutch in or something. no wonder got ATF..  :devil2: will go read up

I also thought got auto clutch lol~ so its a totally diff thing  :bleh:
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: pizzaboy on June 03, 2008, 11:44:18 PM
wat about switchin off the ignition while waitin for light to turn green?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: iagree on June 04, 2008, 12:25:58 AM
dont know about netural but parking the rpm idles at 800, i put D step brake idles at 600 or so.  :D

oh, i noticed that too
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: detach8 on June 04, 2008, 10:38:36 AM
wat about switchin off the ignition while waitin for light to turn green?

that helps, but not if is only 30 seconds.. i think it straisn teh battery having to keep cranking your car
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: liewks on June 04, 2008, 10:48:30 AM
Going to N with the engine idling while stopped at the lights will use less fuel than keeping it in D. This is a generally accepted fact. I've measured it on the Honda Jazz CVT with a Scangauge. Unfortunately Scangauge doesn't work on the Latio :-(.

Coasting to lights in N? It depends. If you need to stop quickly, keep the car in D. The fuel injectors will cut off (in the CVT anyway) until the car slows below 18km/h. After that, the torque converter unlocks and the engine receives fuel to avoid stalling. If you are quite far from the lights, you will probably gain some fuel savings by coasting in N. If you have your tyres inflated to higher pressures, you can coast for a fairly long distance. You can probably coast a good 400m on level ground and drop your speed from 50km/h to ~40km/h.

Automatic transmissions do have clutches. When you shift to N, the forward drive clutch opens so that no power is transferred from the torque converter to the drive pulley. The Latio CVT has a planetary gear shaft to perform reverse. Engaging reverse activates another set of clutches. I think the 2008 version of the Latio has automatic Neutral. So the 10-15 mode for the face lifted version is 19.4km/L instead of 18.2km/L. It also has improved torque converter lockup at lower speeds and runs the alternator only when it is efficient to do so. It also has the all important FC meter!!

I turn off the engine at long traffic lights. I don't think the battery needs to put out a lot of energy to crank a warmed up, well lubricated engine. It starts very fast.

If you are careful and have a good route, the Latio CVT can beat the Japanese 10-15 mode fuel consumption figures. I got 22.12km/L for my last tank of petrol. This does not happen all the time... That's 2km/L short of the Jazz's 10-15 mode number.
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: iagree on June 04, 2008, 08:12:32 PM
Today morning, i tried to switch to N, i noticed,

At D, 60rpm
Switch from D to N at traffic light, rpm shoot to 80.

Huh!
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: liewks on June 05, 2008, 04:49:09 AM
Do you mean it went from 600rpm to 800rpm? Was your A/C on?

Today morning, i tried to switch to N, i noticed,

At D, 60rpm
Switch from D to N at traffic light, rpm shoot to 80.

Huh!
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: david1881 on June 05, 2008, 08:43:08 AM
No worries.  It is normal.  As you engage N, the engine load decrease suddenly and spins faster as a result.  ECU will then automatically adjust the idling speed. 
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: iagree on June 05, 2008, 11:42:03 AM
Do you mean it went from 600rpm to 800rpm? Was your A/C on?


oh ya
with N = 800
with D = 600
With airocn on

Why?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: detach8 on June 05, 2008, 02:58:54 PM
correct me if i am wrong...
the a/c pulls on the engine , also when you engage D your engine is actually engaged in gear to the torque converter, thus zapping up some power from you engine and reducing its idling speed
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: liewks on June 07, 2008, 03:17:33 PM
With A/C on and compressor kicking in, and with gear shift in N, RPM's up to 800+ appear to be the norm.

With A/C off and in N, it is usually dead on at 700rpm.

oh ya
with N = 800
with D = 600
With airocn on

Why?
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: iagree on June 09, 2008, 11:34:47 AM
With A/C on and compressor kicking in, and with gear shift in N, RPM's up to 800+ appear to be the norm.

With A/C off and in N, it is usually dead on at 700rpm.


but with aircon on, N=800, D=600, donno what logic is that. if so, then we shldn't switch to N leh.
Title: Re: Switching to Neutral Gear at stationary saves Fuel? (4AT/CVT)
Post by: andromeda2000 on June 10, 2008, 05:45:35 AM
but with aircon on, N=800, D=600, donno what logic is that. if so, then we shldn't switch to N leh.

I feel that it is because D actually drain some energy when idling, that's why it had lower rpm. IMO, I think that switching to N is better at traffic light.