|
S80 '06-'16 / V70 & XC70 '07-'16 General Forum for the P3-platform S80 and 70-series models |
Information |
|
TF-80SC at the lightsViews : 3586 Replies : 40Users Viewing This Thread : |
|
Thread Tools | Display Modes |
Jan 27th, 2023, 12:40 | #1 |
Senior Member
Last Online: Yesterday 15:39
Join Date: Jan 2022
Location: Reading
|
TF-80SC at the lights
When in D do our auto boxes "disengage" after a period of not moving? And if they don't is it worth popping into N until you move again?
|
Jan 27th, 2023, 15:15 | #2 |
Experienced Member
Last Online: Today 08:30
Join Date: Jun 2007
Location: L/H side
|
Best just to put the handbrake on...
__________________
My comments are only based on my opinions and vast experience . |
Jan 27th, 2023, 15:50 | #3 |
Premier Member
Last Online: Today 08:13
Join Date: Jul 2012
Location: Lenzie
|
I always go into N at lights
__________________
V70 D5 SE Geartronic 215bhp Saville Grey 2012MY 940 LPT Manual 1996 740 SE 1990 |
Jan 27th, 2023, 15:50 | #4 |
Senior Member
Last Online: Yesterday 15:39
Join Date: Jan 2022
Location: Reading
|
Why? In case I'm on a incline?
So I'm not asking because of that, I'm talking about a mechanism for prolonging the life of the box by disengaging when you haven't moved for a while, because you're stuck in traffic or at red lights. I believe some modern boxes have this but wasn't sure if ours had it. |
Jan 27th, 2023, 15:51 | #5 |
Senior Member
Last Online: Yesterday 15:39
Join Date: Jan 2022
Location: Reading
|
|
Jan 27th, 2023, 16:32 | #6 | |
Experienced Member
Last Online: Today 08:30
Join Date: Jun 2007
Location: L/H side
|
Quote:
Highway code below... In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again. Law RVLR reg 27
__________________
My comments are only based on my opinions and vast experience . |
|
The Following User Says Thank You to Clan For This Useful Post: |
Jan 27th, 2023, 17:04 | #7 | |
Senior Member
Last Online: Yesterday 15:39
Join Date: Jan 2022
Location: Reading
|
Quote:
|
|
Jan 27th, 2023, 17:41 | #8 |
Premier Member
Last Online: Yesterday 11:52
Join Date: Nov 2015
Location: Poole
|
.......and the parking brake handles hill starts and automatically releases as the car moves away. It's the first time I've had a parking brake like this and I always smile when I use it as it seamlessly lets me pull away. Unless I haven't put on my seat belt when Nanny Volvo wags her finger at me and won't let me drive away!
__________________
2012 XC70 SE Lux Polestar 230 bhp D5 Auto Oyster Grey |
Jan 27th, 2023, 18:25 | #9 |
Senior Member
Last Online: Yesterday 15:39
Join Date: Jan 2022
Location: Reading
|
Parking brake aside, the original question is yet to be answered. Maybe we don't know?
I've been doing some testing and it's not entirely obvious if the box does or doesn't disengage after a few seconds of having the brake on. |
Jan 27th, 2023, 19:02 | #10 |
VOC Member
Last Online: Yesterday 23:12
Join Date: Dec 2001
Location: Hull
|
To the best of my knowledge, the box does not disengage when sitting in D with the brakes on. I seem to recall (and may well be completely wrong!) that in some early versions it did do so.
I think the intention may have been to slightly improve the fuel economy but in practice it caused more problems than it solved and I believe the software was updated accordingly. Problems were said to include jerky operation and unpredictable behaviour when pulling away. I seem to remember it was the subject of much discussion on the forum at the time. I have also seen it stated that taking the box out of gear for each stop causes more wear than simply leaving it in D with the brakes on. I can see the logic inasmuch as any clutch will wear during the engagement process and probably to a lesser extent during disengagement. Minimising the number of times D is selected should help miminise the wear on the gear selection clutches. My own practice is to hold the car on the handbrake and leave it in D unless the stop is sufficiently long to justify stopping the engine, for example at level crossings and some temporary traffic lights. I've also seen it said that holding the car on the footbrake after heavy braking can result in the discs cooling unevenly and may increase the likelihood of them warping. However most modern handbrakes use the same discs and pads as the footbrake, albeit usually on just the rear wheels. More hearsay than a definitive answer I'm afraid. Martin |
The Following User Says Thank You to Martin Cox For This Useful Post: |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|