Author Topic: Fuel Cutoff?  (Read 19367 times)

Offline SoL

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Re: Fuel Cutoff?
« Reply #20 on: July 18, 2008, 12:54:28 PM »
Ah I see. Because when I see the light turn red in front of me, I let go the accelerator, but then the engine brake don't let me roll as much, so I still have to pump a little more gas.

Thats why I thought changing to N is better mah. HAHA!

Thanks!  :thumbsup:

Offline iagree

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Re: Fuel Cutoff?
« Reply #21 on: July 18, 2008, 01:47:18 PM »
Ah I see. Because when I see the light turn red in front of me, I let go the accelerator, but then the engine brake don't let me roll as much, so I still have to pump a little more gas.

Thats why I thought changing to N is better mah. HAHA!

Thanks!  :thumbsup:

Chg to N is ok right? But no point to chg to N if you only need to wait for 1min for the light to turn green?
sorry, i must agree because i don't know how to disagree. agreeeee only....

from
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Offline clarence

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Re: Fuel Cutoff?
« Reply #22 on: July 18, 2008, 04:00:36 PM »
Shifting of auto gear from D to N when car is in motion will damage the auto gearbox in the long run.

If you don;t intend to keep your car for long, then it might be ok   :unsure:

Offline iagree

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Re: Fuel Cutoff?
« Reply #23 on: July 19, 2008, 03:46:25 PM »
Shifting of auto gear from D to N when car is in motion will damage the auto gearbox in the long run.

If you don;t intend to keep your car for long, then it might be ok   :unsure:

iagree.
try not to switch gear anyhow.

regards.
sorry, i must agree because i don't know how to disagree. agreeeee only....

from
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Offline clarence

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Re: Fuel Cutoff?
« Reply #24 on: July 19, 2008, 04:07:37 PM »
And during cold starts in the mornings, I always allow the engine to run for 10 seconds to allow the oil to flow and lubricate the parts before I shift from P to D and driver off.

Offline darrylker

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Re: Fuel Cutoff?
« Reply #25 on: July 19, 2008, 09:31:59 PM »
And during cold starts in the mornings, I always allow the engine to run for 10 seconds to allow the oil to flow and lubricate the parts before I shift from P to D and driver off.

Sometimes quite rush in the morn, so no time to warmup engine till blue light off, but i make sure i don't rev over 2000rpm until engine is warmed-up... ;)

Offline darrylker

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Re: Fuel Cutoff?
« Reply #26 on: July 19, 2008, 09:38:37 PM »
I always practice brake less. Onli no choice den i brake, normally will try my best not to press any brakes.
You can also try looking far, the furthest traffic condition or the next traffic light, den decide to press acc or dont press anithing, until u are close enuff to a stop den press brake.
When approaching a red light, I will aim for the shortest line and release acc and not braking onli when close, coz incase it turns green I still have some inertia with mi, so can move off much easier

Just 2 cents

Hey bro xuan, that's what I practice during drivin too...and the best thing is it'll also improve your FC  :thumbsup:

Offline CustomGolf

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Re: Fuel Cutoff?
« Reply #27 on: July 19, 2008, 10:43:11 PM »
True, When I see red light far ahead and no car behind me, I just left go acc. The car will slow down to ~20kmj then there is a sudden slight rush forward guess the car decide to pump some oil to engin at that time. I am driving a CVT so the rush is not due to gear change. Did not change to N

Ooi, another Malaysian in our forum ah. KMJ ;D

Offline detach8

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Re: Fuel Cutoff?
« Reply #28 on: July 20, 2008, 01:51:34 PM »
i'm not sure what effect does shifting out from D to N while in motion has - probably damage to TC lockup clutch if it was done at high speeds? but don't ever shift from N back into D while in motion because that will most certainly put strain on the bands that activate specific gear ratios, etc. also don't do stuff like rev your engine in N and throw your gear into D, this will certainly get some stuff all burnt up as well. i used to have a friend borrow my old car and do "engine braking", which i told him off... if u wanna do crazy ******** like these, please rent a car! (which he actually did, and i pray for that altis..)

Offline clarence

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Re: Fuel Cutoff?
« Reply #29 on: July 20, 2008, 06:45:53 PM »
Sometimes quite rush in the morn, so no time to warmup engine till blue light off, but i make sure i don't rev over 2000rpm until engine is warmed-up... ;)


There is no need to warm up in the morning until the "Cold Engine" blue light goes off.

Just 10 SECONDS will do, to allow the gearbox and engine oil to flow through the metal parts inside your engine and lubricate 'em before you drive off.

Offline fineLatio

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Re: Fuel Cutoff?
« Reply #30 on: July 20, 2008, 07:26:20 PM »
it's not called an oil temp indicator for nothing right? the tempeature sensor is there to check that the car (engine oil) is warmed up to optimal operational condition before the blue light goes off.

If that is really unneccessay, why wasn't an engine oil flow LED indictor built instead?

Offline clarence

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Re: Fuel Cutoff?
« Reply #31 on: July 20, 2008, 08:07:20 PM »
The blue light is an engine temperature indicator, not an engine oil temperature indicator.

Offline Jazz

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Re: Fuel Cutoff?
« Reply #32 on: July 20, 2008, 10:08:52 PM »
It water temp not oil temp.  :smile:

Offline detach8

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Re: Fuel Cutoff?
« Reply #33 on: July 21, 2008, 01:54:07 AM »
its water temp bro. sometimes in cold country the water will freeze and cause the coolant to freeze up and the engine can't start. singapore is not a big deal. just start the car and u will realize the RPM is quite high, let the RPM settle down and u can actually drive off already. in fact you can drive off immediately. just do it slowly and by the time u get out of the carpark, the engine is already starting to warm up a bit.

Offline Jazz

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Re: Fuel Cutoff?
« Reply #34 on: July 21, 2008, 07:29:04 PM »
its water temp bro. sometimes in cold country the water will freeze and cause the coolant to freeze up and the engine can't start. singapore is not a big deal. just start the car and u will realize the RPM is quite high, let the RPM settle down and u can actually drive off already. in fact you can drive off immediately. just do it slowly and by the time u get out of the carpark, the engine is already starting to warm up a bit.

Some correction, even if the coolant freezes (although seldom will freeze unless sub zero temperature), the engine will still able to start. For a engine to ease of start up depending on spark plug, you can change to a cold plug for cold start. Once engine start, the coolant will be "defrost" anyway. Engine oil will aid in lubricating plus a secondary role of cooling the engine as well. Hope this info help to clear all misunderstanding.  :smile:

Offline detach8

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Re: Fuel Cutoff?
« Reply #35 on: July 21, 2008, 11:41:42 PM »
thx for correction bro!

Offline Ying

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Re: Fuel Cutoff?
« Reply #36 on: July 22, 2008, 12:32:39 AM »
 :yehyeh: Mari Kita....

Offline Jazz

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Re: Fuel Cutoff?
« Reply #37 on: July 22, 2008, 01:07:27 PM »
thx for correction bro!

No worry Bro, we all learning together.  :D

Offline liewks

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Re: Fuel Cutoff?
« Reply #38 on: July 26, 2008, 12:03:11 AM »
Given our local temperatures, it is probably very safe to start the engine and just drive off at a relaxed pace. It will probably take longer to warm up the transmission fluid if you're not moving the car.

My understanding of spark plugs is that:

- cold plugs are thermally more conductive than hot plugs. They are meant for aggressive driving styles as it takes a higher engine load to keep them at optimal temperatures. Low plug temperatures will accumulate carbon deposits because there is insufficient temperature to burn it off. Excessively high temperatures will damage the electrodes.

- hot plugs are less thermally conductive and these are specified for our cars as engine loads tend to be lower and the plugs need to maintain an optimal temperature to prevent fouling.

But as always, I could be wrong.

When shifting to N, the forward drive clutch disengages. This is NOT the torque converter. It is debatable whether shifting to N while at speed will damage the transmission. In any case, I shift to N at red lights. It reduces my engine load and fuel consumption while avoiding vibration. Having the engine turning the torque converter while the output shaft is held stationary will only heat up the transmission fluid... I have connected ScanGauge to a Jazz CVT before and found that shifting to N while stationary will reduce fuel consumption.

For the Latio CVT, torque converter lock-up occurs at speeds above 18km/h. If you release the accelerator above that speed and keep the shifter in D, the ECU will cut-off the fuel. Because the HR15DE does not have valve shut-off (like the Civic Hybrid), the engine will act like an air pump and you will feel the car decelerating at a higher rate than if you shift to N. I am guessing that fuel cut-off is cancelled when engine speed falls to about 1100rpm or when the toque converter is unlocked. When the Latio TCM (transmission control module) detects a downslope, it will drop the CVT gear ratio to increase engine brake force. This will slow the car even more. This is less obvious/ negligible if you enter the decline at speeds above 70km/h.

You can sometimes cancel the torque converter lock-up by releasing the accelerator and then gently tapping it again and letting go. This only works at speeds below 60km/h. This is useful when coasting downhill around bends--you don't want to slow down, but you don't want to have the car in N either (for safety's sake).

My personal style is to take my foot off the accelerator when I anticipate the lights wrongly or if they are unpredictable and I need to stop fairly quickly. If I see a red light far ahead, I will shift to N and allow the car to coast to a stop.

I think the HR15DE + CVT is a fairly good set up for hypermiling. I imagine that holding a steady 75km/h on highways without air-conditioning will return close to 24km/L. Personally, I have not achieved this before. However, it is possible to get an average of 21km/L over a tank of petrol if you have the right route and driving style.