Author |
Topic: Correct way to drive an auto ? (Read 1960 times) |
|
RICHIJONES
Newbie
2 litre 16V Ultima
 
Posts: 22
|
 |
Correct way to drive an auto ?
« on: Dec 30th, 2004, 9:34pm » |
 Quote  Modify
|
Hi All.
Can anyone settle an argument between 2 of my mates.
One says that the correct way to drive with a auto box is to select drive and leave it in drive for the whole journey, when you come to a stop hold it on the foot brake and let the box do all the work. He says selecting between drive and neutral is not needed and causes wear to the hydrolics in the box.
My other mate says whenever you stop select neutral and apply handbrake just as you would in a manual, leaving in drive when stopped will put extra load an wear on the torque converter and also engine will be loaded so fuel economy will suffer.
So who is right ? I tend to leave in drive if i am only going to be stopped for less than 30 seconds.
|
|
 IP Logged |
|
|
|
scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
|
|
Re: Correct way to drive an auto ?
« Reply #2 on: Dec 31st, 2004, 9:04am » |
Quote Modify
|
hi there
this is a copy of a post from eric r to the mailing list......
name,
Yes, the drive in the autobox is supplied via a torque converter, which is a form of turbine. Perhaps I could explain how it works. Imagine you have a windmill set up in the garden and you squirt a garden hose at it. You will expect the windmill to spin because the force of the water is transferred to the blades of the windmill. Further, if you think about it, the force of the water is greater when the blades are turning slowly, and decrease as the blades speed up, and this is the torque conversion. Equally, common sense says that there will be more force delivered to the blades if you use a 3" fire hose rather than a garden hose to squirt water at it.
Now imagine the torque converter as two halves of an orange with the segment walls left in and filled with fluid. One half is driven by the engine and as it spins it throws the fluid outward into the vanes of the other half which is forced to turn and this torque drives the input shaft of the gearbox and the transmission fluid pump. While the driven half is slower than the fluid, more force is applied which decreases as the driven vanes speed up, until both halves of the converter are going at almost the same speed. At this point the torque converter is no longer required, and a small clutch is engaged which locks the two halves together - the TCC - there is now direct drive through to the back wheels.
The transmission fluid pump is also spinning and pressurises the internal oil channels which engage the gears, and it is this you may hear whining slightly from rest as it builds up the pressure in the gearbox. The gears are fixed in a sun/planet configuration, and brake bands controlled by fluid pressure through solenoids lock one sun wheel each, forcing others to turn, and this gives the four ratios. On the A4LDE the gear solenoids are controlled directly by the PCM, but on earlier gearboxes fantastically complicated channels and valves controlled the main line pressure from one valve to another to produce the correct ratio according to speed.
That's a matchbox explanation of the auto drive - there are complications, like a third disk between the halves of the torque converter to prevent the fluid returning in the wrong direction and anti-cavitation, but that's essentially how it works. With nothing connecting the two halves except for fluid, there is no reason to disengage the drive while stationary. The torque converter produces only enough torque to provide a creep at tickover, and this is easily checked with the footbrake. The only thing to remember is that catalysts can be damaged by very long periods of engine idle, so if stuck in a traffic jam it is best to turn off the engine altogether.
Actually, continually disengaging the drive subjects the gear selection mechanism to ten or twenty times more wear than is necessary, as well as increasing the work of the transmission fluid pump which has to make up the loss of main line pressure while it was in P.
In the handbook on P90 Ford advise -
Stopping - release the accelerator pedal and depress the foot brake (doh!) Leave the selector lever where it is. To move off again release the foot brake and depress the accelerator pedal.
HTH
Eric R
|
|
IP Logged |
|
|
|
RICHIJONES
Newbie
2 litre 16V Ultima
Posts: 22
|
|
Re: Correct way to drive an auto ?
« Reply #3 on: Dec 31st, 2004, 5:30pm » |
Quote Modify
|
Thanks for the above explination, now i know more about how the torque converter works i can see it is better to stay in drive. Selecting neutral at every stop just means more work and wear for the box and selector. Automatic means just that.
Thanks
|
|
IP Logged |
|
|
|
tjp_lawson
Junior Member
I love bob( thats my engine by the way)
Posts: 85
|
|
Re: Correct way to drive an auto ?
« Reply #4 on: Dec 31st, 2004, 5:35pm » |
Quote Modify
|
yes very good thats probably the best explanation i`ve ever read, in a nutshell, thats why the transmission will hold the car on a gradient without using the footbrake
|
|
IP Logged |
tyroe
|
|
|
Badboytunes
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #5 on: Jan 2nd, 2005, 6:15pm » |
Quote Modify
 Remove
|
I disagree. When left in gear at traffic lights /junctions the box will be under load but the vehicle is forced to remain static using the brakes. this is turn heats up the box and over a period of time may cause premature wear to the brake bands and the oil pump. Also the highway code states that when stic at junctions ect you should always put the car in neutral and apply the handbrake
Cheers Nick
|
|
IP Logged |
|
|
|
Eric_R
Administrator
Cosworth Owner 1998 - 2006 & site co-founder
Posts: 1792
|
|
Re: Correct way to drive an auto ?
« Reply #6 on: Jan 3rd, 2005, 3:19pm » |
Quote Modify
|
Nick,
No, that's nonsense.  There is no 'heating' of the fluid because no torque is being delivered and the 'box is 'freewheeling'. You could remain at idle and hold the box on the footbrake all day and the fluid would not overheat - the surface area of the autobox sump is perfectly adequate to lose what heat there is. You'd probably damage the catalysts, though. 
If you should select N while stopped then Ford would absolutely have to say so in their Owners Handbook - but they do not, and in fact they state the exact opposite - and that's for the reasons stated.
Don't know what Highway Codes you are looking at. Rules 146-159 refer to appropriate behaviour at junctions and there is no mention whatever of taking the car out of gear and setting the handbrake 
|
|
IP Logged |
After a Cosworth, anything else is just ... ordinary
|
|
|
Snoopy
Administrator
Very old.BAD tempered and missing friends.
Posts: 6278
|
|
Re: Correct way to drive an auto ?
« Reply #7 on: Jan 3rd, 2005, 3:51pm » |
Quote Modify
|
Nick, I have to agre with Eric on this one... The correct way to drive and automatic is as he states.... NO need to drop into neautral at all when staionary at juctions etc as long as you keep your foot on the brake...I have had automatics for many a year now ans never had any problems with brake bands or the like and I used to drive around london a lot ...
more wear on the selctor dropping it into neutral all the time....
If you need a upto date copy of the Highway code then go here
http://www.highwaycode.gov.uk/00.shtml
|
|
IP Logged |
HELP the FORUM.Please DONATE
|
|
|
Vulcan
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #8 on: Jan 3rd, 2005, 5:25pm » |
Quote Modify
Remove
|
I no longer drop it into neutral anymore unless I am in stationary traffic for a really long period when I do it just to save having my foot on the brake all the time. 
That said my father in law had an Omega that used to drop itself into neutral if it was stationary with a foot on the brake for more than 2 minutes. You didn't need to select drive when wanting to move off as it automatically would do it for you if it had selected neutral itself in this way. I doubt that Vauxhall would have had such a feature if it was totally unnecessary.. would they?
|
|
IP Logged |
|
|
|
Baz
Moderator
Senior Member
S Reg. 1998 24v Cosworth S2.9 COS (Deceased)
Posts: 4009
|
|
Re: Correct way to drive an auto ?
« Reply #9 on: Jan 3rd, 2005, 5:28pm » |
Quote Modify
|
The correct way to drive an auto (Cosworth)?
Bloody quickly if you ask me!!
|
|
IP Logged |
|
|
|
George
Full Member
ash black 2.3 16v ghia 134000miles
 
Posts: 211
|
|
Re: Correct way to drive an auto ?
« Reply #10 on: Jan 3rd, 2005, 5:32pm » |
Quote Modify
|
i agree sideways and fast
|
|
IP Logged |
|
|
|
Mmonster
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #11 on: Jan 3rd, 2005, 5:51pm » |
Quote Modify
Remove
|
is there any other way ??!!
|
|
IP Logged |
|
|
|
phuturephantasy
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #12 on: Jan 3rd, 2005, 9:40pm » |
Quote Modify
Remove
|
Well I'm glad I'm not the only owner who drives his Scorpio to the limits (at appropriate times of course).
|
|
IP Logged |
|
|
|
granorpio
Full Member
1998 Silver Facelift Cosworth
Posts: 589
|
|
Re: Correct way to drive an auto ?
« Reply #13 on: Jan 3rd, 2005, 10:25pm » |
Quote Modify
|
on Jan 3rd, 2005, 5:28pm, Baz wrote:The correct way to drive an auto (Cosworth)?
Bloody quickly if you ask me!! |
|
GOOD ONE 
|
|
IP Logged |
- Mike -
So nearly said "goodbye" but now Scorpio will see another day, alongside the replacement! eek!
|
|
|
mr._floppy
Junior Member
Posts: 100
|
|
Re: Correct way to drive an auto ?
« Reply #14 on: Jan 3rd, 2005, 11:29pm » |
Quote Modify
|
Once you get an auto you become a right lazy b****r, so even keeping your foot on the brake at traffic lights
is almost hard work. I'd rather the car didn't creep AT ALL when idling and in "drive ", and only started to move forward at round about 1000/1100 rpm.
|
|
IP Logged |
|
|
|
geraghtyg
Full Member
2001 XG25
Posts: 215
|
|
Re: Correct way to drive an auto ?
« Reply #15 on: Jan 4th, 2005, 2:01am » |
Quote Modify
|
Well if I'm going to be sitting in traffic or a lights for a while, I usually stay in drive and just pull the handbrake up. It needs a fairly good yank though or the car will creep. Maybe I'm putting more wear on the handbrake cable though! And when I say "a fairly good yank", I don't mean that I'm trying to reef the thing - I just have to bring it up a little further than would normally do when parking and switching off the engine.
|
|
IP Logged |
Graham G, Dublin, Ireland
|
|
|
Badboytunes
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #16 on: Jan 4th, 2005, 12:13pm » |
Quote Modify
Remove
|
on Jan 3rd, 2005, 3:19pm, Eric_R wrote:Nick,
No, that's nonsense. There is no 'heating' of the fluid because no torque is being delivered and the 'box is 'freewheeling'. You could remain at idle and hold the box on the footbrake all day and the fluid would not overheat - the surface area of the autobox sump is perfectly adequate to lose what heat there is. You'd probably damage the catalysts, though.
If you should select N while stopped then Ford would absolutely have to say so in their Owners Handbook - but they do not, and in fact they state the exact opposite - and that's for the reasons stated.
Don't know what Highway Codes you are looking at. Rules 146-159 refer to appropriate behaviour at junctions and there is no mention whatever of taking the car out of gear and setting the handbrake |
|
Oh well it looks like im wrong on that one then  Lynn passed her test in an auto and was told to put the car in neutral and apply the handbrake at junctions.... maybe she had a instuctor who was a bit old fashioned i dont know.... As for the box heating up i spose it makes sence whatr u say eric but i remember being told this when i used to drive auto's .... HMMMM thinking about it it was my grandfather who told me this LOL. i think technology has moved on a bit.....
soz for any confusion caused 
Cheers Nick
|
|
IP Logged |
|
|
|
Badboytunes
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #17 on: Jan 4th, 2005, 12:16pm » |
Quote Modify
Remove
|
As for the 24v the correct way
manulaly into 1st.......... 6200rpm then;
2nd......... 6200rpm......
you catch my drift? LOL
|
|
IP Logged |
|
|
|
craig
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #18 on: Jan 4th, 2005, 12:38pm » |
Quote Modify
Remove
|
nick
amanda passed in an auto as well,and was told by the instructor to do exactly the same as you have quoted,again the instructor was from the old school (approx 60 ish),so maybe this is just a case of being cautious by the instructors,and also might just be a "this is how you should drive".........
never last's long anything like that after passing your test now does it
|
|
IP Logged |
|
|
|
Badboytunes
Guest
|
|
Re: Correct way to drive an auto ?
« Reply #19 on: Jan 4th, 2005, 4:43pm » |
Quote Modify
Remove
|
Quite right Craig......
it should st8....... rest ur arm on the door ledge, spin the steering wheel round with the palm of your hand ect ect. much more realistic i think. BTW i have just been demoted to Lynns clio now as i did promise her my escy ghia so now i dont even own a ford
|
|
IP Logged |
|
|
|
|
Home
Help
Search
Members
Login
Reply
Send Topic
Print