Use of Neutral vs Drive when temporarily stopped.

[Pielight]

I’m seriously getting worried that I’m progressively becoming more OCD with age!

Anyway, I have increasingly become fixated on what causes the least wear and tear to the transmission of my GSF, ie, shift lever left in D vs N. The owners manual simply states, shift to N if stopped for an ‘extended’ length of time. That is obviously open to interpretation in scenarios such as traffic lights have just changed to red with you at the back of the queue etc. 
 

Staying in drive will certainly use more fuel whilst stopped in order for the engine to overcome the drag without stalling. Heat will also be generated by the transfer of the extra energy (fuel), but I’m quite confident that the transmission coolers are designed to dissipate this heat for a considerable amount of time without issue. Shifting to Neutral will offload the engine so less fuel consumed and zero additional transmission heat generated. However, there is bound to be additional wear when re-engaging drive (I tend to do this with brake pedal released in mitigation) which may or may nor become significant after hundreds and thousands of events. So the key question is what is the extended length of time, where the additional wear is a lesser evil than standing with the engine and transmission under a small amount of load… the answer obviously is very subjective.

Another consideration is it’s a known fact that sitting with your foot on the brake can cause disc warping if the discs are hot (the parking brake only applies on the rear discs which only provide 25% of braking effort so presumably don’t get as hot, even though smaller). Sitting in drive requires the brake pedal to be pressed harder to resist the creep, so may increase the risk of warping.

I know I’m over thinking it and it is a wholly insignificant issue in the scheme of things, but would be interested in anyone’s take on it.

 

 

 

 

[Herbie]

2 hours ago, Pielight said:

I know I’m over thinking it

Let me just reiterate that

2 hours ago, Pielight said:

I know I’m over thinking it

And in case you're still unsure, I'll say that I think you're overthinking it too

I've driven nothing but automatics for more than 30, maybe even 35 years (never wanted an auto - until the first time I drove one that is  ) and I've never had any auto box (or parts thereof) fail on me or wear out, nor any brake part, transmission cooler or any associated part, despite taking some of them to 100k miles and beyond.

Having learned to drive and passed my test in a manual, I was always used to the 'handbrake on and move to Neutral' process and I probably did that more often than not, but I also did my fair share of leaving it in Drive and just standing on the brakes.

In other words, I truly don't think it matters. Just do what you do and enjoy driving the car.

[Mihanicos]

I also share your considerations and engage neutral when I stop. On the other hand if you use the automatic transmission like most people do, as Herbie outlined, there will be no adverse circumstances.

Chris.

[Herbie]

4 hours ago, Mihanicos said:

I also share your considerations and engage neutral when I stop. On the other hand if you use the automatic transmission like most people do, as Herbie outlined, there will be no adverse circumstances.

Chris, your profile shows you as having a GS450h and if that's correct, you should always keep it in drive unless you think it'll be a while before you get moving again, in which case you should put it in park.

The reason for this is that the hybrid system will not recharge the batteries in neutral.

[NemesisUK]

Neutral in an auto box has no use whatsoever in day to day driving. It's only there to enable the car to be pushed around the workshop or possibly towing away.

In a hybrid even more so, as has been mentioned, in neutral the hybrid system cannot recharge the batteries.

If the wait is going to be prolonged use Park otherwise simply hold in drive.

[Mihanicos]

Thanks Herbie  you are absolutely right. I normally drive my Lexus on motorways, very rarely in the city.

Chris.

[Thackeray]

Whatever decision you make, unfortunately you're never going to be able to tell whether it made any difference to the longevity of the car or the fuel consumption.

But that doesn't mean it's of no interest to think about the theory! So here are my thoughts on your dilemma.

15 hours ago, Pielight said:

there is bound to be additional wear when re-engaging drive (I tend to do this with brake pedal released in mitigation)

On a conventional automatic, every time you move the gear selector there are clutches in the transmission which are engaged and disengaged. Although they should last for many years, they will nonetheless wear slightly every time you do this. For this reason, on automatics I've owned I've always adopted the policy of leaving it in Drive for short stops.

As for releasing the brake pedal, I would have thought the impact this had would be extremely small. The clutches are still engaged and disengaged producing the same amount of wear. And the power from the engine has a torque converter between it and the wheels, so I would have thought the impact of the drag from the engine on the transmission will be little different whether you have the brakes on or not.

As for the hybrid transmission, when you shift from Drive to Neutral or any other selection, nothing mechanical actually happens to the gears in the transmission. (Except in Park the parking pawl is engaged). So there may be a little extra wear on the gear selector from moving from Drive to Neutral. But nothing happens in the transmission itself.

[Texas]

‘Extended length of time’ is always going to be relative but You should always take vehicle out of gear when waiting at traffic lights ( especially where pedestrians may be crossing)

[Rabbers]

An interesting but somewhat academic thread.  I really can’t think of a situation where an automatic car needs to be put in N unless it needs pushing or towing as the result of breaking down or having a dead Battery.  In fact I would think it possible for a car (especially a Lexus👌!) to go its entire life without its owner(s) ever having put it in N.

[Rob RCF]

10 hours ago, NemesisUK said:

Neutral in an auto box has no use whatsoever in day to day driving. It's only there to enable the car to be pushed around the workshop or possibly towing away.

4 hours ago, Rabbers said:

An interesting but somewhat academic thread.  I really can’t think of a situation where an automatic car needs to be put in N unless it needs pushing or towing as the result of breaking down or having a dead battery.  In fact I would think it possible for a car (especially a Lexus👌!) to go its entire life without its owner(s) ever having put it in N.

Actually one good "feature" of neutral is that it enables you to turn off the engine without fully shutting down the car. This is useful when at a standstill in traffic for example. Just shift back into park afterwards, and when you want to restart the engine push the gear selector to the side and then press engine stop/start. Stereo stays on as well.

Disclaimer - I haven't fully tested this whole engine off and restart procedure yet, but it should work.

[Womble72]

I “did” always select N when stationary BUT after buying the eldest an auto golf with gear issues (wouldn’t come out of 1st until warm)……the gearbox specialist that repaired the box said NOT to take out of gear unless it’s for a long time, he said every time you move between N and D you are engaging n disengaging solenoids repeatedly and causing premature wear, I now don’t select N unless I know it’s for a length of time, I will use the foot brake if I don’t want to hold the brakes on.

[Pielight]

Thanks everyone for your replies which are both interesting and generally confirm my over thinking this!

There is a strong consensus among you to just leave the transmission in drive, unless stopping for a substantial period of time - I'll be employing this principle myself.

To be fair, there was some foundation to my concern - I've spent the last 43 years involved in driving trains, some of which in bygone days had semi auto transmissions (4 or 5 speed) that used 'fluid couplings' (also known as fluid flywheels) - basically a hydraulic clutch. Standing in other than neutral for an extended duration would build up serious heat which in severe cases caused sacrificial core plugs in the fluid coupling housing to melt and drain the transmission (thereby fulfilling their intended purpose of averting a fire!). I realise, however, that those old fluid couplings were designed to stand only with the gearbox in neutral as the fluid coupling did not have an oil cooler. Clearly, I still bear the mental scars from my experience of operating those old relics!!

[Rabbers]

Although I haven’t owned or, as far as I can recall, driven a car with a manual box for thirty years or more, I must admit that I still receive a signal from the recesses of my mind to put the car into Neutral when stopped at lights.  The signal is immediately countermanded by another stronger one telling me not to do so and stay in D, but the process illustrates how the Clutch Down/Shift to N/Handbrake On sequence as originally learned became instinctive (and perhaps a bit flexible with experience).

[Malc]

On 9/23/2021 at 9:51 PM, Pielight said:

I’m seriously getting worried that I’m progressively becoming more OCD with age!

you're absolutely right in thinking this, your are ................... leave it in D and run down a pedestrian or two OR pop it in N and float around a little .......  OCD often comes to us all at some advanced time in our lives ............  so I suggest leave her in D and take out one or two bodies that get a little too close for comfort

Malc

[Pielight]

5 hours ago, Rabbers said:

Although I haven’t owned or, as far as I can recall, driven a car with a manual box for thirty years or more, I must admit that I still receive a signal from the recesses of my mind to put the car into Neutral when stopped at lights.  The signal is immediately countermanded by another stronger one telling me not to do so and stay in D, but the process illustrates how the Clutch Down/Shift to N/Handbrake On sequence as originally learned became instinctive (and perhaps a bit flexible with experience).

Just to add weight to the problem is I also  still have manual vehicles including motorcycles. I'll just have to recondition myself!

[Pielight]

2 hours ago, Malc said:

you're absolutely right in thinking this, your are ................... leave it in D and run down a pedestrian or two OR pop it in N and float around a little .......  OCD often comes to us all at some advanced time in our lives ............  so I suggest leave her in D and take out one or two bodies that get a little too close for comfort

Malc

Ok will do - as long as the unfortunates don't damage the car!! lol

[Rabbers]

Paul & Malcom:  All this talk about OCD has got me seriously worried since I previously believed the condition more frequently affects young or youngish adults than the more mature and wiser constituents of Lexus’ traditional target groups such as ourselves.

[Womble72]

2 minutes ago, Rabbers said:

Paul & Malcom:  All this talk about OCD has got me seriously worried since I previously believed the condition more frequently affects young or youngish adults than the more mature and wiser constituents of Lexus’ traditional target groups such as ourselves.

I drive a manual daily and a 1000cc bike, my biggest issue is the wipers 😂….. can’t get that into my head between cars!….. I can go from either or and not even contemplate going for a clutch BUT the wiper stalk gets me every time 🙄

[Pielight]

1 hour ago, Rabbers said:

Paul & Malcom:  All this talk about OCD has got me seriously worried since I previously believed the condition more frequently affects young or youngish adults than the more mature and wiser constituents of Lexus’ traditional target groups such as ourselves.

Certainly not in my experience Renato, EVERYTHING gets worse -  this aging business has absolutely nothing going for it (apart from you don't give a jot about doing/wearing anything that loses street, as that's long gone anyway!). Whoever coined the phrase "life begins at 40" were obviously delusional! 😂

[Pielight]

1 hour ago, Womble72 said:

I drive a manual daily and a 1000cc bike, my biggest issue is the wipers 😂….. can’t get that into my head between cars!….. I can go from either or and not even contemplate going for a clutch BUT the wiper stalk gets me every time 🙄

Ditto - the wipers on my GSF were a nightmare to get used to! There is no detent positions for left or right - the stalk just returns to centre after switching on. You then have to indicate in the opposite direction to switch off - to begin with I'd be indicating continuously switching from from left to right after every turn! Not so bad now, but it still catches me now and again. 

[D Johnson]

Hello everyone, I’m very new to Lexus (a recovering 5 series owner with all the mental trauma that entailed) but I, like the OP, am concerned about the effects on my IS 300h brake discs of sitting in D at traffic lights and whilst in queues holding on the foot pedal.  Also, I cannot find the handbrake and increasingly suspect that there may not actually be one to find!  This is most discombobulating…. Any advice will be gratefully received.   

[Malc]

4 minutes ago, D Johnson said:

Any advice will be gratefully received.

don't use words like " discombobulating "  we're only simple humans with limited vocabulary ........ sounds more complex than some Latin phrases I  occasionally use on here 

btw .........  welcome Marianne

Malc

[Womble72]

15 minutes ago, D Johnson said:

Hello everyone, I’m very new to Lexus (a recovering 5 series owner with all the mental trauma that entailed) but I, like the OP, am concerned about the effects on my IS 300h brake discs of sitting in D at traffic lights and whilst in queues holding on the foot pedal.  Also, I cannot find the handbrake and increasingly suspect that there may not actually be one to find!  This is most discombobulating…. Any advice will be gratefully received.

 

Think the handbrake is a footbrake, check for a high level foot pedal next to your left leg, push down to engage, push down and release to dis engage, or it’s possibly an electronic one which would be illustrated (P) somewhere on the dash……. You won’t miss that BM I can assure you 

[eleveneleven]

I've often wondered the same thing OP. I've had DSG's in the past and always kept my foot on the brake pedal at lights, stop n go traffic or short ish stops never had an issue 

with the Lexus however, I hear a slight rubbing sound when the brake is applied not sure what it is I'm guessing (and hoping) its a brake disks/pads issue and not the gearbox. For that reason I've been sticking it into neutral for any wait longer than a minute or so. 

Another thing I seem to be a little paranoid about is parking on steep incline, My driveway for example. every time I engage D from P when its on the drive there's quite a loud "clunk" sound. Doesn't sound like it's doin the gearbox any good at all. I'd get it occasionally with some of my previous cars but as they were all leased so under warranty I didn't really worry about it. 

womble72's answer makes sense though so I'll be leaving it D from now on 

 

[Thackeray]

29 minutes ago, eleveneleven said:

Another thing I seem to be a little paranoid about is parking on steep incline, My driveway for example. every time I engage D from P when its on the drive there's quite a loud "clunk" sound. Doesn't sound like it's doin the gearbox any good at all.

Have a look at this thread. If you scroll down a bit you'll see a picture of the parking pawl along with an explanation of why you get a clunk. There's also a video which I think is supposed to suggest a way to avoid this happening.