Sorry, was rush typing, I meant is N not the same as P..........mechanically, but without the lock parking pawl thing ? 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

I would never leave it in D if I were stopped at lights. You can feel it wanting to go, so that must mean something is under strain.... You should try in in low ratio! I was in a muddy field at the weekend and used the low ratio. When you have your foot on the brake you can still feel it wanting to go at tickover speed. Previously..
Vogue SE TD6
Defender 90 2.4
Defender 110 TD5
Vogue 3.5 EFI

I'm all for mechanical sympathy, but I'll wager all that constant loading and unloading of the entire drivetrain by going into and out of gear causes far more wear than just leaving it in drive and gently holding it on the brakes.

But its the torque converter!!!

Its just the pressure of the Oil on the blades inside the converter:

Good point........

I'm liking this thread. Has got me thinking.

I've had auto cars on and off for a total of about 13 of my driving years, and have never left them in D when stationary.......

I take the point about wear going in and out of D,

Not sure what the answer is then........ 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

I suppose you could be doing mechanical damage to properties the transfer fluid if you leave it in D when stationary.
Given the history of TD6 gearboxes I would have thought you would want the transfer fluid in as good a condition as possible.

Arrgh!!

We have been here before:

http://www.fullfatrr.com/forum/topic4657.html

and LR Driving School Video 27 minutes in:

 .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Not sure about the boxes in the L322, but many older ZF boxes are damaged if you leave the engine running for too long in N. This was due to the oil flow round the box not being correct - in fact I think the oil pump only worked in gear.

My understanding is that certain older boxes don't take the pump drive from the input shaft, directly or indirectly, but that's why you shouldn't tow automatics with the driven wheels on the ground.

Joe90 wrote:

Arrgh!!

We have been here before:

http://www.fullfatrr.com/forum/topic4657.html

and LR Driving School Video 27 minutes in:

He is stopped to remove a tree, so going to neutral/park is normal. Same arguments as in my first post - you can add trees and LR Experience instructors to the list of begonias, pets, and small children.

And going to N and releasing the brake before going to P ensures that there is no pre-load on the parking pawl.

Simes wrote:

Not sure about the boxes in the L322, but many older ZF boxes are damaged if you leave the engine running for too long in N. This was due to the oil flow round the box not being correct - in fact I think the oil pump only worked in gear.

This is absolutely correct for the ZF 5 HP 22/24 found in the P38. I'm pretty sure this was corrected for the later ZFs found in the L322 (RRPhil would know) and it was never an issue for the GM5L40E in the TD6. And you had to leave the motor running for a long time (and usually at higher RPMs too) such as for AC charge/diagnosis in a garage. 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

The impeller of the torque converter is basically an oil pump and therefore requires power to drive it.

Taking the 5HP24 as an example, assuming the engine speed at idle is 700rpm and the K-factor at stall for the Sachs W260 torque converter is around 125rpm/(Nm)0.5, then the engine will be producing 31Nm to drive the converter’s impeller with the vehicle stationary and the transmission in gear. You’re not particularly aware of this because the engine control system simply fuels the engine to maintain 700rpm.

If you select neutral, the A-clutch is disengaged allowing the turbine shaft to turn freely and the torque converter speed ratio to increase to practically unity. The absorbed torque is now trivial as you’re only overcoming clutch drag and the engine management system will back off the fuel to close-loop control around 700rpm again.

The ‘in-gear idle’ phases of the urban/city fuel economy drive cycles used by the car industry can typically add up to a third of the total fuel used during the whole cycle i.e. the fuel required to idle the engine against a stalled torque converter is surprisingly significant.

In the past decade transmission manufacturers and calibrators have therefore developed solutions such as reverting the transmission to neutral (without the driver’s knowledge) until the brake switch is deactivated at which point the forward clutch is re-engaged and the vehicle launches as expected.

Phil

SteveMFr wrote:

(RRPhil would know)

RRPhil wrote:

The ‘in-gear idle’ phases of the urban/city fuel economy drive cycles used by the car industry can typically add up to a third of the total fuel used during the whole cycle i.e. the fuel required to idle the engine against a stalled torque converter is surprisingly significant.

Really! But then the MPG difference between manual and auto versions of the same car should be greater, tho, shouldn't it? 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Hi Steve,

On a pure urban stop-start cycle it certainly used to be, but the difference is now reduced by the introduction of automatic neutral idle control. Unfortunately in the case of the L322 we don’t have a manual version to compare it to.

Phil

So, in basic terms, what you're saying is that being in N in traffic when stationary is better and a lot more economical? Si. <This is my name.

I eat rat poison.

A man ain't truly been insulted until he stands buck naked in front of a woman and she didn't even notice. Or care.

Life is too short to worry about the tiny difference being in D or N or P at the lights will make - my L322 is 10 years old and drives perfectly, messing with the selector at the lights is not going to do anything to it (other than scare the person behind when I select R by mistake). "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone