M-DCT drivers~ do you guys put N when you make full stop?

shksman · 09-05-2011, 11:10 AM

One of my buddy who drive Acura TL, he puts N every time he make full stop.
He is saying, it saves some gas and helps transmission.
How's this sounds to you?

gthal · 09-05-2011, 11:14 AM

No I don't put mine in neutral... would only be extra wear/tear on the tranny (maybe not much) taking it in and out of gear. When you put it in neutral, you can hear the DCT coming out of gear (which means there is mechanical action in the transmission somewhere) and that, to me, would likely cause more issues long term than simply leaving it as is. I'm not an expert though so maybe I'm wrong.

When the car comes to a stop, the clutch is not engaged anyway (i.e. like having the clutch depressed on a 6MT) so I don't see how that saves gas vs. neutral. You are effectively in neutral but, again, I'm no expert.

EuroTrip · 09-05-2011, 11:20 AM

your friend is delusional. All cars will idle the same in neutral as in drive. The only thing I could understand him thinking maybe that holding the brake somehow fights the engine from moving forward...but i honestly don't think that uses gas. Your M3 DCT will not roll forward when releasing the brake... That is,unless he is talking about going neutral using the brakes to stop the car instead of the engine. Plus, stop trying to get gas mileage out of your M3. You paid $1300 gas guzzler fee, so no matter what you will always be behind.

The new 2011 M3's have auto start stop feature...which cuts the motor on full stop. Unfortunately, the break even point of it saving you gasoline vs. the engine running is being stopped for more than 80 seconds. There aren't many lights that long where I live. I really only use it when I go through a drive-thru.

geneatals · 09-05-2011, 11:31 AM

no

Daft · 09-05-2011, 02:50 PM

I put into N sometimes when I see a redlight way up ahead then just coast all the way to it. It coasts much easier in N then if left in gear. I do this just cuz I'm lazy to keep my foot on the peddle not to save gas/tranny.

Chowster · 09-05-2011, 05:43 PM

Nope. I don't either. There's also a safety issue of not having the car in gear to accelerate out of an unexpected situation or emergency.

gthal · 09-05-2011, 06:15 PM

Quote:

Originally Posted by Chowster

Nope. I don't either. There's also a safety issue of not having the car in gear to accelerate out of an unexpected situation or emergency.

Good point and one often overlooked.

SEI · 09-06-2011, 03:07 AM

since we are on this topic. is it alright to neutral it all the way down a mountain? (did this recently). was on neutral for probably 15km

lve2xlr8 · 09-06-2011, 02:34 PM

When you come up to a light and make a full stop and take your foot off the brake it doesn't go anywhere, the dct is essentially in neutral so there's no point in putting it in N.

sawzall · 09-06-2011, 03:41 PM

Quote:

Originally Posted by SEI

since we are on this topic. is it alright to neutral it all the way down a mountain? (did this recently). was on neutral for probably 15km

It shouldn't cause any damage to the transmission.

gthal · 09-06-2011, 07:01 PM

Quote:

Originally Posted by SEI

since we are on this topic. is it alright to neutral it all the way down a mountain? (did this recently). was on neutral for probably 15km

Coasting in neutral burns more gas than allowing the car to coast in gear... there was another recent thread on this. Also, the risk is there if you needed to accelerate for some reason but was out of gear.

Chowster · 09-06-2011, 10:32 PM

Quote:

Originally Posted by SEI

since we are on this topic. is it alright to neutral it all the way down a mountain? (did this recently). was on neutral for probably 15km

15km In neutral? Wow. More importantly, why?

bigjae1976 · 09-06-2011, 10:46 PM

On my 330 6sp, I put the car in neutral when stopped which saves wear on the throw out bearing.

Not sure if that is the case with the DCT.

SEI · 09-08-2011, 11:39 AM

Quote:

Originally Posted by Chowster

15km In neutral? Wow. More importantly, why?

I was running out of gas and decided to neutral it all the way down.. Worked actually...

SEI · 09-08-2011, 11:44 AM

Quote:

Originally Posted by gthal

Coasting in neutral burns more gas than allowing the car to coast in gear... there was another recent thread on this. Also, the risk is there if you needed to accelerate for some reason but was out of gear.

Dunno about that... In neutral I'm at 800 rpm the whole way down. But if I kept it in gear there will be resistance when I move and i was going down at abt 20-30 km/h so that woulda been like 2000 rpm.

gthal · 09-08-2011, 07:13 PM

Quote:

Originally Posted by SEI

Dunno about that... In neutral I'm at 800 rpm the whole way down. But if I kept it in gear there will be resistance when I move and i was going down at abt 20-30 km/h so that woulda been like 2000 rpm.

It isn't about RPM. When you coast in gear the fuel injectors shut off and no fuel is delivered to the engine... none. The engine continues to run because it is connected to the wheels through the engaged transmission and the wheels are turning... the whole concept of inertia. In neutral, the fuel injectors do continue to supply fuel because the transmission isn't turning the engine.

So... in neutral... burning gas. In gear and coasting... no gas is provided to the engine.

There was a whole thread on this where some people didn't understand this and lots of folks who know a lot more about engines than me corrected everyone.

SEI · 09-09-2011, 06:02 AM

Ok, was thinking you were right about the coasting thing so I tried it out. No matter what gear I'm at the car will slow itself down due to engine breaking.. So I think neutral would still save more fuel since it will let you coast at speed for longer instead of the car slowing itself down..

bobbyd1961 · 09-09-2011, 06:51 AM

Quote:

Originally Posted by shksman

One of my buddy who drive Acura TL, he puts N every time he make full stop.
He is saying, it saves some gas and helps transmission.
How's this sounds to you?

ridiculous

FVM3 · 09-09-2011, 09:36 AM

No

09-05-2011, 11:10 AM	#1
shksman Private 21 Rep 62 Posts Drives: 2011 X5 3.5i,2008 e92 M3 Join Date: Jun 2011 Location: WA iTrader: (0)	M-DCT drivers~ do you guys put N when you make full stop? One of my buddy who drive Acura TL, he puts N every time he make full stop. He is saying, it saves some gas and helps transmission. How's this sounds to you?
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09-05-2011, 11:14 AM	#2
gthal Major General 1903 Rep 5,678 Posts Drives: 2018 340i xDrive Join Date: Jul 2007 Location: Canada iTrader: (2)	No I don't put mine in neutral... would only be extra wear/tear on the tranny (maybe not much) taking it in and out of gear. When you put it in neutral, you can hear the DCT coming out of gear (which means there is mechanical action in the transmission somewhere) and that, to me, would likely cause more issues long term than simply leaving it as is. I'm not an expert though so maybe I'm wrong. When the car comes to a stop, the clutch is not engaged anyway (i.e. like having the clutch depressed on a 6MT) so I don't see how that saves gas vs. neutral. You are effectively in neutral but, again, I'm no expert. __________________ 2020 X3 M40i \| Black \| Current DD 2020 C8 Corvette \| Z51 \| Torch Red ... built and waiting for delivery 2016 M2 \| Long Beach Blue \| 6MT 2015 M4 \| Austin Yellow \| DCT 2012 MB C63AMG \| 2011 E92 M3 \| 2010 E92 M3
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09-05-2011, 11:20 AM	#3
EuroTrip BMW FAN 43 Rep 723 Posts Drives: 2002 E46 M3 AW 6MT Join Date: Jan 2008 Location: Laguna Beach, CA iTrader: (5)	your friend is delusional. All cars will idle the same in neutral as in drive. The only thing I could understand him thinking maybe that holding the brake somehow fights the engine from moving forward...but i honestly don't think that uses gas. Your M3 DCT will not roll forward when releasing the brake... That is,unless he is talking about going neutral using the brakes to stop the car instead of the engine. Plus, stop trying to get gas mileage out of your M3. You paid $1300 gas guzzler fee, so no matter what you will always be behind. The new 2011 M3's have auto start stop feature...which cuts the motor on full stop. Unfortunately, the break even point of it saving you gasoline vs. the engine running is being stopped for more than 80 seconds. There aren't many lights that long where I live. I really only use it when I go through a drive-thru.
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09-05-2011, 11:31 AM	#4
geneatals Ninja 390 Rep 4,014 Posts Drives: 2019 530e Join Date: Dec 2007 Location: So Cal (SFV) iTrader: (3)	no __________________ 2019 AW G30 530e l ZPP l ZMP l ZDH Retired: 2016 F80 M3, 2012 E90 M3, 2008 535i
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09-05-2011, 02:50 PM	#5
Daft Major 384 Rep 1,202 Posts Drives: 2021 M2C Join Date: Jan 2009 Location: Ontario, Canada iTrader: (2) Garage List 2003 BMW M3 [10.00] 2011 BMW M3 [9.71]	I put into N sometimes when I see a redlight way up ahead then just coast all the way to it. It coasts much easier in N then if left in gear. I do this just cuz I'm lazy to keep my foot on the peddle not to save gas/tranny.
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09-05-2011, 05:43 PM	#6
Chowster E60_to_E90 36 Rep 1,201 Posts Drives: 2011 E90 M3 Join Date: Aug 2010 Location: Surrey, BC, Canada iTrader: (2)	Nope. I don't either. There's also a safety issue of not having the car in gear to accelerate out of an unexpected situation or emergency. __________________ 2011.5 E90 Dinan M3, SS II, M-DCT, EDC, M Drive. 20" MORR VS8.2 wheels Performance Mods: Dinan St.1 suspension, exhaust, intake; TTPs; BPM St.II, DCT, servo tunes Cosmetic Mods: OEM CF splitters, mirrors, center console, spoiler; Arkym CF diffuser; LUX; tint
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09-06-2011, 03:07 AM	#8
SEI Second Lieutenant 47 Rep 283 Posts Drives: M3 Join Date: Jul 2007 Location: Jakarta iTrader: (0) Garage List 2016 Mercedes c63s amg [0.00] 2013 Kawasaki Ninja ... [0.00] 2007 Yamaha R6 [0.00] 2014 Mercedes S500 [0.00] 2011 BMW X3 35i [0.00] 2012 Mercedes E63 AMG [0.00] 2006 Mercedes S500 [0.00] 2007 BMW 335i (E92) [0.00] 2011 BMW M3 [0.00]	since we are on this topic. is it alright to neutral it all the way down a mountain? (did this recently). was on neutral for probably 15km __________________ now: 2008 335i (E92), 2011 M3 (E92), X3 35i (F25),2012 E63 AMG (W212), 2013 Kawasaki Ninja 250, 2007 Yamaha R6 gone:2009 GTR, 2007 335i (E93) 2004 M3 (HPF stg 3), 2008 Civic Lx, 2007 Z4M Roadster, 2001 Gembala GT550, 2007 CLS 55, 2007 STI, 2004 M3
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09-06-2011, 02:34 PM	#9
lve2xlr8 Major 195 Rep 1,186 Posts Drives: E92 M3 Join Date: Aug 2008 Location: Los Angeles iTrader: (11)	When you come up to a light and make a full stop and take your foot off the brake it doesn't go anywhere, the dct is essentially in neutral so there's no point in putting it in N. __________________ R8 V10 6MT S65 M3 Tesla 3
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09-06-2011, 10:46 PM	#13
bigjae1976 Major General 1570 Rep 8,075 Posts Drives: 11 E90 M3 Individual Join Date: Mar 2006 Location: Houston, TX iTrader: (22) Garage List 2004 BMW M3 [4.50] 2011 BMW E90 M3 [5.25] 2013 BMW 328i [5.00]	On my 330 6sp, I put the car in neutral when stopped which saves wear on the throw out bearing. Not sure if that is the case with the DCT. __________________ 2018 F30 320iX Melbourne Red 2011 E90 M3 Monte Carlo Blue 2004 E46 M3 Imola Red 2000 E36/7 Z3 Steel Blue
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09-09-2011, 06:02 AM	#17
SEI Second Lieutenant 47 Rep 283 Posts Drives: M3 Join Date: Jul 2007 Location: Jakarta iTrader: (0) Garage List 2016 Mercedes c63s amg [0.00] 2013 Kawasaki Ninja ... [0.00] 2007 Yamaha R6 [0.00] 2014 Mercedes S500 [0.00] 2011 BMW X3 35i [0.00] 2012 Mercedes E63 AMG [0.00] 2006 Mercedes S500 [0.00] 2007 BMW 335i (E92) [0.00] 2011 BMW M3 [0.00]	Ok, was thinking you were right about the coasting thing so I tried it out. No matter what gear I'm at the car will slow itself down due to engine breaking.. So I think neutral would still save more fuel since it will let you coast at speed for longer instead of the car slowing itself down.. __________________ now: 2008 335i (E92), 2011 M3 (E92), X3 35i (F25),2012 E63 AMG (W212), 2013 Kawasaki Ninja 250, 2007 Yamaha R6 gone:2009 GTR, 2007 335i (E93) 2004 M3 (HPF stg 3), 2008 Civic Lx, 2007 Z4M Roadster, 2001 Gembala GT550, 2007 CLS 55, 2007 STI, 2004 M3
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09-09-2011, 09:36 AM	#19
FVM3 Major General 273 Rep 5,751 Posts Drives: e92 m3, f30 328i Join Date: Sep 2010 Location: Los Angeles iTrader: (2)	No
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