Stop/start Traffic

[Grey One]

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

[knitware]

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

Keep it in D, use the parking brake instead of the brake peddle if you want to.

[Guest]

n

[Grey One]

don't keep it in Drive that is causing the clutch to constantly slip. But it in neutral and use the handbrake just like a manual.

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

That's two totally contradictory replies :) anyone else have a view?

My gut feeling is the neutral select but Lexus themselves seem to say keep it in D...

[knitware]

don't keep it in Drive that is causing the clutch to constantly slip. But it in neutral and use the handbrake just like a manual.

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

So many arguments with this topic and I don't wan't to carry it on, try Google.

But: The previous poster is talking absolute TOSH, burning clutches? Please don't give bad advice.

If you are in a traffic jam and not moving anywhere then P is good. If you wan't to knock it into N at lights then that's fine too. The easy way is to leave the car in D with foot on brake.

Really, that is all there is too it, no clutch burns or anything horrid. All personal preference, how long you have stopped for etc. Just enjoy your car and take Lexus's advice!

[kam05]

As someone who is fairly new to driving autos (currently have a C Class Merc since March this year), the advice I have been given is to leave the car in D with the foot on the brake- dropping it into N or P when stopping at the lights all the time doesn't do the auto box any good?

[The Editor]

As someone who is fairly new to driving autos (currently have a C Class Merc since March this year), the advice I have been given is to leave the car in D with the foot on the brake- dropping it into N or P when stopping at the lights all the time doesn't do the auto box any good?

Keep it in 'D' - Will not cause any problems whatsoever.

[kam05]

As someone who is fairly new to driving autos (currently have a C Class Merc since March this year), the advice I have been given is to leave the car in D with the foot on the brake- dropping it into N or P when stopping at the lights all the time doesn't do the auto box any good?

Keep it in 'D' - Will not cause any problems whatsoever.

Thanks- just as I thought.

[fjcfarrar]

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

Leave it in D with your foot on the brake unless you are going to be stopped for one of those endless traffic-light sequence or other lengthy delay, in which case stick it in N. If you use the parking brake in N, it easy to forget to let it off and then have the car beep at you, plus it won't necessarily hold you stationary if you use D. If you use N, just don't half doze-off and forget to put it into D before you put your right foot down again and then feel like a wally! No harm/wear will result if stationary in either D or N; but the fluid flywheel equivalent used for first gear will get hotter if stopped a long time in D (harmlessly) and its your fuel that heats it.

[Grey One]

Thanks Everyone, that really helps.

I had one other question... how do you get a MPG figure from the onboard computer? I've tried to poke around the menu on the central display but can't find anything referencing this.

Thx

[fjcfarrar]

Thanks Everyone, that really helps.

I had one other question... how do you get a MPG figure from the onboard computer? I've tried to poke around the menu on the central display but can't find anything referencing this.

Thx

"DISP" button on Right-Hand-Side of steering wheel. Changes display each time pressed. Just keep pressing it until you get to mpg etc.

[Grey One]

Thanks Everyone, that really helps.

I had one other question... how do you get a MPG figure from the onboard computer? I've tried to poke around the menu on the central display but can't find anything referencing this.

Thx

"DISP" button on Right-Hand-Side of steering wheel. Changes display each time pressed. Just keep pressing it until you get to mpg etc.

Thx will try this

[Guest]

n

[Guest]

How exactly does fuel heat a flywheel!?

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

Leave it in D with your foot on the brake unless you are going to be stopped for one of those endless traffic-light sequence or other lengthy delay, in which case stick it in N. If you use the parking brake in N, it easy to forget to let it off and then have the car beep at you, plus it won't necessarily hold you stationary if you use D. If you use N, just don't half doze-off and forget to put it into D before you put your right foot down again and then feel like a wally! No harm/wear will result if stationary in either D or N; but the fluid flywheel equivalent used for first gear will get hotter if stopped a long time in D (harmlessly) and its your fuel that heats it.

[TigerFish]

Lexus will say what sounds easier and you will also need a clutch sooner. How often does the clutch/transmission fluid need changed?

Unless I'm missing something, and the ISF has a manual gearbox with an automatic clutch, I assume it has a torque convertor. In which case, what clutch are you talking about?

[knitware]

shjh01

Lexus will say what sounds easier and you will also need a clutch sooner. How often does the clutch/transmission fluid need changed?

DUDE, stop with the WRONG advice, nothing you say is correct. You will not need a clutch sooner, or will it harm the gearbox leaving it in D.

[Guest]

This advanced member has his "Knitware" in a fuddle he is obviously more experienced than myself. I apologise for not going into technical detail of how and automatic transmission works I though it would have been more simple to explain the torque transfer mechanics as a clutch as most people are familiar with the theory of what a clutch is!

However this is sound advice here from "fjcfarrar"

Leave it in D with your foot on the brake unless you are going to be stopped for one of those endless traffic-light sequence or other lengthy delay, in which case stick it in N. If you use the parking brake in N, it easy to forget to let it off and then have the car beep at you, plus it won't necessarily hold you stationary if you use D. If you use N, just don't half doze-off and forget to put it into D before you put your right foot down again and then feel like a wally! No harm/wear will result if stationary in either D or N; but the fluid flywheel equivalent used for first gear will get hotter if stopped a long time in D (harmlessly) and its your fuel that heats it.

shjh01

Lexus will say what sounds easier and you will also need a clutch sooner. How often does the clutch/transmission fluid need changed?

DUDE, stop with the WRONG advice, nothing you say is correct. You will not need a clutch sooner, or will it harm the gearbox leaving it in D.

DUDE how TOTALLY BADASS AMERICAN are you??? DUDE.

its not wrong it is simplified.

A simple question was asked, so an answer was supplied with a simplified justification.

[knitware]

This advanced member has his "Knitware" in a fuddle he is obviously more experienced than myself. I apologise for not going into technical detail of how and automatic transmission works I though it would have been more simple to explain the torque transfer mechanics as a clutch as most people are familiar with the theory of what a clutch is!

However this is sound advice here from "fjcfarrar"

Leave it in D with your foot on the brake unless you are going to be stopped for one of those endless traffic-light sequence or other lengthy delay, in which case stick it in N. If you use the parking brake in N, it easy to forget to let it off and then have the car beep at you, plus it won't necessarily hold you stationary if you use D. If you use N, just don't half doze-off and forget to put it into D before you put your right foot down again and then feel like a wally! No harm/wear will result if stationary in either D or N; but the fluid flywheel equivalent used for first gear will get hotter if stopped a long time in D (harmlessly) and its your fuel that heats it.

shjh01

Lexus will say what sounds easier and you will also need a clutch sooner. How often does the clutch/transmission fluid need changed?

DUDE, stop with the WRONG advice, nothing you say is correct. You will not need a clutch sooner, or will it harm the gearbox leaving it in D.

DUDE how TOTALLY BADASS AMERICAN are you??? DUDE.

its not wrong it is simplified.

A simple question was asked, so an answer was supplied with a simplified justification.

This is not simplified, this is wrong, incorrect, rubbish:

"don't keep it in Drive that is causing the clutch/equivalent(torque converter for the pedantic) to constantly slip. Put it in neutral and use the handbrake just like a manual."

And this piece of advice shows a real lack of knowledge:

"Lexus will say what sounds easier and you will also need a clutch sooner."

I'm not american and I am not going to argue with you. I'm sorry if I upset you but I dislike ill informed and incorrect advice. The 'simple' answer you gave is incorrect.

Indeed it was a simple question, answered by many correctly, D is fine, no issues with clutch or gearbox damage and Leuxs' advice is sound advice.

[knitware]

Well, this is the oddest thread and it's turning odder. This is getting silly.

Thank you for your email-

I am sorry to have upset you but I feel I have to continue to do so. Your advice is wrong.

The trouble with academia (PHD)is that sometimes you lose all practical perception. FYI I am a senior design engineer at Siemens, my previous roll was at Rolls Royce Nuclear (defence). This however is immaterial as the answer to the original question remains.

Leaving your car in D will not adversely effect longevity of the clutch or gearbox. Perhaps when you finish your studies you can qualify this.

Can we end this topic now..........

Edited September 19, 2011 by janey
Publication of PRIVATE message - text removed

[fjcfarrar]

How exactly does fuel heat a flywheel!?

Hi Everyone

My first post on here - the IS-F is the first automatic I've owned so I'm obviously more focussed on driving it properly than the auto rental cars I've had before. My question is when waiting in traffic jams or at traffic lights is it okay to flip into neutral or park rather than keeping drive enegaged and brake pedal pressed all the time? I'm more concerned about gearox/brake wear than economy...

Cheers

Grey One

Leave it in D with your foot on the brake unless you are going to be stopped for one of those endless traffic-light sequence or other lengthy delay, in which case stick it in N. If you use the parking brake in N, it easy to forget to let it off and then have the car beep at you, plus it won't necessarily hold you stationary if you use D. If you use N, just don't half doze-off and forget to put it into D before you put your right foot down again and then feel like a wally! No harm/wear will result if stationary in either D or N; but the fluid flywheel equivalent used for first gear will get hotter if stopped a long time in D (harmlessly) and its your fuel that heats it.

The torque converter used in first gear acts like a coupling via oil between a finned plate at the engine and another at the other end of the same assembly connected to the drive train. When at tick-over in D, enough power is transmitted through this arrangement to allow the car to creep along. When stationary, the output from the gearbox is braked to zero, and the power/energy that had been available to make the car creep has to go somewhere, and is converted to heat. Basically if you stir oil with a finned wheel it resists the movement and generates heat (as per a classical textbook method to convert rotational mechanical effort into temperature-rise in a liquid etc.). In N, the driving finned wheel is disconnected so this doesn't happen. Either way, it is no big deal, and the only time to even think about it is if you know you are going to be stationary for quite a few minutes, when N is theoretically a more economical option - or for even more economy; switch the engine off.

This is a simplification. There is a fuel-overhead involved in the process of restarting the engine to be weighed up against leaving the engine running. The real geek enthusiast could calculate the optimum delay for the engine to be switched off. I take the view that hot engines can be disinclined to start again, so usually leave it running ;)

[simranjit Jhita]

All i know is....Put it in 'D' and the car will very ferociously move forward when you press the right side pedal. :)

[fjcfarrar]

All i know is....Put it in 'D' and the car will very ferociously move forward when you press the right side pedal. :)

I hope you mean if you press the right-hand pedal hard then OK - but if you mean you can't pull off gently and slowly when you want to; there is something dreadfully wrong with your ISF

If an ISF is as it should be; there is no car easier to drive in slow or stop/start traffic - even in Sport mode.

[wow300]

In amougst the arguements this is an interesting thread as i always knock it into neutral believing there to be less strain on the box, i have taken lexus's up to 300,000 miles with no problems. only believing less strain, less wear...

[Guest]

I agree. However Knitware is a highly intelligent and highly strung on his own opinion so watch out ;)

In amougst the arguements this is an interesting thread as i always knock it into neutral believing there to be less strain on the box, i have taken lexus's up to 300,000 miles with no problems. only believing less strain, less wear...

[fjcfarrar]

In amougst the arguements this is an interesting thread as i always knock it into neutral believing there to be less strain on the box, i have taken lexus's up to 300,000 miles with no problems. only believing less strain, less wear...

A good, sound principle. However the gearbox/torque converter is designed to withstand the hugely greater strain of overcoming the inertia due to the car's mass when you eventually pull off - most of the engine's available power could even be applied with a heavy right foot.

So what you say is fundamental and true; but the strain when stationary in D for a while is too small to be a significant contributor to shortening the life of any of the drive-train.

So whatever suits best. I suppose N is safer than D because if your foot on the brake relaxes or slips off; the car is never going to lurch into the car in front. On the other hand, in D everything is ready to go when the traffic starts to move again.......