Idle in an auto

billyboym3 · 11-12-2015, 03:05 PM

Hi All, when you pull up at some lights in an auto, do you knock it into neutral or keep it into drive?

my previous auto I just kept my foot on the brake and kept it in Drive, however this car I find myself knocking it into neutral so not to burn anything out as such. Im sure it has its own method of disabling the clutch? or does it?

k9david · 11-12-2015, 05:37 PM

I just leave it in drive with foot on the brake.
Only time I consider anything different is at night and I know its going to be a long stop. I started doing this when following another car in a jam and I was nearly blinded by the constant dazzle from the lights.

djgandy · 11-13-2015, 05:10 AM

There is no clutch, it's an auto. There are a few topics on this. IMO there is no point changing out of D because there are barely any forces on the gearbox anyway when you are on the brake.

The sample applies in dual clutch transmissions too. The clutches won't be engaged when foot is on the brake. The software knows you aren't moving and can work out the mechanics itself.

Good reasons to go into N are if you don't want to blind the driver behind you, or you've been hooning it and you don't want to leave deposits on your brakes.

AWSAWS · 11-13-2015, 05:30 AM

If you've just come to a stop after some really hard braking then it can be a good idea to swap to Park to avoid warping the disc as the pads will be really hot and you'll be holding that in one spot on the disc.

Rich_D · 11-13-2015, 08:28 AM

The handbook says leave it in D, with either the foot brake (short stop) or handbrake (longer stop, assuming it holds LOL), I only put it into N or P if I'm going to be stopped for more than a couple of minutes

mob17 · 11-13-2015, 10:18 AM

I usually leave it in D with the brake on, or in N with the handbrake if i have done heavy braking just prior.

I have never left it in D with the handbrake on, is that really in the manual?

HighlandPete · 11-13-2015, 11:52 AM

Quote:

Originally Posted by billyboym3

Hi All, when you pull up at some lights in an auto, do you knock it into neutral or keep it into drive?

my previous auto I just kept my foot on the brake and kept it in Drive, however this car I find myself knocking it into neutral so not to burn anything out as such. Im sure it has its own method of disabling the clutch? or does it?

There is drag on the torque converter when left in Drive, but the gearboxes are clever bits of kit these days, have a feature to off load the TC at idle, while in Drive.

It is known as NIC (Neutral Idle Control). When you come to a halt with the footbrake applied NIC is activated. One of the gearbox brake packs goes into slip mode, allows internal components to rotate and reduces TC drag by something like 90%. You lift off the brake and NIC deactivates (brake pack engages) and you are ready to go. If working correctly you don't feel a thing, it is only when there is an issue with NIC do you possibly get a jolt on moving off.

We therefore understand the system is designed to be left in Drive with NIC assisting economy when idle.

HighlandPete

billyboym3 · 11-14-2015, 12:47 PM

well thanks guys, I shall stop worrying and leave it in drive unless i am tanking it.

11-12-2015, 03:05 PM	#1
billyboym3 Private First Class 12 Rep 173 Posts Drives: BMW 520D Join Date: Nov 2013 Location: Oxford iTrader: (0)	Idle in an auto Hi All, when you pull up at some lights in an auto, do you knock it into neutral or keep it into drive? my previous auto I just kept my foot on the brake and kept it in Drive, however this car I find myself knocking it into neutral so not to burn anything out as such. Im sure it has its own method of disabling the clutch? or does it?
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11-12-2015, 05:37 PM	#2
k9david Enlisted Member 5 Rep 30 Posts Drives: 320i E92 Join Date: Jul 2015 Location: Dorset iTrader: (0)	I just leave it in drive with foot on the brake. Only time I consider anything different is at night and I know its going to be a long stop. I started doing this when following another car in a jam and I was nearly blinded by the constant dazzle from the lights.
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11-13-2015, 05:10 AM	#3
djgandy Colonel 144 Rep 2,335 Posts Drives: E93 M3 Join Date: Aug 2012 Location: London iTrader: (0) Garage List 2011 M3 [0.00]	There is no clutch, it's an auto. There are a few topics on this. IMO there is no point changing out of D because there are barely any forces on the gearbox anyway when you are on the brake. The sample applies in dual clutch transmissions too. The clutches won't be engaged when foot is on the brake. The software knows you aren't moving and can work out the mechanics itself. Good reasons to go into N are if you don't want to blind the driver behind you, or you've been hooning it and you don't want to leave deposits on your brakes.
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11-13-2015, 05:30 AM	#4
AWSAWS Colonel 278 Rep 2,340 Posts Drives: E92 GC Turbos, FBO, 335i DCT Join Date: Nov 2012 Location: Valhalla iTrader: (0)	If you've just come to a stop after some really hard braking then it can be a good idea to swap to Park to avoid warping the disc as the pads will be really hot and you'll be holding that in one spot on the disc. __________________ GC Turbos, FBO, JB4, DCT, Port Meth injection, BMS Charge Pipe, NGK plugs. EBC brakes and pads, LED Angel lights, LED foglights, LCI rears OCC, Braided brake lines. Custom Diff Lockdown Kit, VTT inlets, TMAP, stage 2+ fuel pump 11.79@119mph (stock turbos) 11.74@129mph (GC Turbos)
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11-13-2015, 08:28 AM	#5
Rich_D Captain 100 Rep 677 Posts Drives: E90 330d M Sport LCI Join Date: Mar 2015 Location: Lancs, UK iTrader: (0)	The handbook says leave it in D, with either the foot brake (short stop) or handbrake (longer stop, assuming it holds LOL), I only put it into N or P if I'm going to be stopped for more than a couple of minutes __________________ BMW E90 330d M Sport LCI in Sapphire Black
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11-13-2015, 10:18 AM	#6
mob17 Major General 397 Rep 5,613 Posts Drives: E92 335D Join Date: Mar 2012 Location: East Midlands, UK iTrader: (5)	I usually leave it in D with the brake on, or in N with the handbrake if i have done heavy braking just prior. I have never left it in D with the handbrake on, is that really in the manual?
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11-14-2015, 12:47 PM	#8
billyboym3 Private First Class 12 Rep 173 Posts Drives: BMW 520D Join Date: Nov 2013 Location: Oxford iTrader: (0)	well thanks guys, I shall stop worrying and leave it in drive unless i am tanking it.
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