PRND12

Indricotherium

Is there some mechanical reason that the selector on automatics is generally PRND?

Surely D should be before R as it is used every single time a car is switched on and R isn't necessarily?

I also see a lot of autos sitting at lights where the reverse light flashes on when the lights go green. This is obviously people who have put the car in P while waiting and then have to go thru R and N to get back to D?

Surely PDNR makes more sense? Or PD21NR where you can select 1 and 2?

colm_mcm

There are a number of reasons for this, mostly safety. It's done in such a way that you can't accidentally select reverse or make the car down change.

Auto boxes are changing nowadays anyway. The lever can be electronic like on bmws.

colm_c

Have a read: http://ask.metafilter.com/40132/Why-PRNDL

Indricotherium

Indricotherium wrote: »

I also see a lot of autos sitting at lights where the reverse light flashes on when the lights go green.

Do people put their autos in P at lights?

Wossack

safer to accidentally shift into neutral at motorway speeds, then into park

colm_mcm

BrownFinger wrote: »

Do people put their autos in P at lights?

Yeah some do. I used to when I had auto. That's a whole other thread!

Cheensbo

BrownFinger wrote: »

Do people put their autos in P at lights?

They sure do, drives me up the wall.

Asked a buddy why he does it, he does it because he doesn't want to burn out the clutch by loading/holding it on the brakes...

bazz26

BrownFinger wrote: »

Do people put their autos in P at lights?

No need if you have an electronic parking brake with the auto hold feature.

jimgoose

Cheensbo wrote: »

They sure do, drives me up the wall.

Asked a buddy why he does it, he does it because he doesn't want to burn out the clutch by loading/holding it on the brakes...

Does he realise that there is no clutch, and the fluid coupling is not in any pain at engine idle speeds? :pac:

bazz26

DSG has a dual clutch for example, no?

jimgoose

bazz26 wrote: »

DSG has a dual clutch for example, no?

Yup. But a PRUNDY lever suggests to me an old-style slushbox, which would have a fluid coupling.

Cheensbo

jimgoose wrote: »

Does he realise that there is no clutch, and the fluid coupling is not in any pain at engine idle speeds? :pac:

Yeah, I've explained the mechanics but I'm wrong either way.. :pac:

biko

Id say
P
N
D
L
R
would be better

Nuw

biko wrote: »

Id say
P
N
D
L
R
would be better

I would say that Neutral is good to have between any forward gear and reverse... I wouldn't have any mechanical knowledge to back this up, but it just make sense to me.

pa990

...

fancy pigeon

"Put it in H..."

It's a common sight to see people put it in park when stopped... I was once in a taxi where the driver coasted in neutral every chance he got :eek:

Indricotherium

fancy pigeon wrote: »

"Put it in H..."

It's a common sight to see people put it in park when stopped... I was once in a taxi where the driver coasted in neutral every chance he got :eek:

Yeah, if I'm going to be stopped for ages I lash it into P, or into N with the handbrake.

I've found that if you are hitting speedbumps fast, that selecting N seems to give the car less of a jerk, but I reckon that might be in my head.

bazz26

I think I've put it in Neutral once in the 3 years I've been driving an auto.

Indricotherium

bazz26 wrote: »

I think I've put it in Neutral once in the 3 years I've been driving an auto.

Every time you drive anywhere you surely go thru N to get to D?

Esel

Indricotherium wrote: »

Every time you drive anywhere you surely go thru N to get to D?

:rolleyes:

colm_mcm

He's got a fancy BMW auto

_Kaiser_

I usually just hold mine at lights with the footbrake, though if stopped for more than the average light sequence I'll use N/P plus the electronic handbrake

I have seen some people who'll park them up without the handbrake. I've done so myself a few times when I had a caliper issue on previous cars, but I never like that little rocking it does when you take your foot off the brake.. always feels like you might snap something.

As for selection order, I think it's grand as is with R and P being at the top of the tree (as they're not used as much) and N separating them from D, S/L etc (plus you have to hold in the button to engage R or P which is a good safety feature)
I almost never use S(port) though. Never need to unless maybe doing a brisk overtake on an N/R-road (which is rare enough too as I do almost entirely motorway runs). I don't think I've used the manual tiptronic/paddle shifts at all in the current car.

dr.fuzzenstein

Mine used to be LSDNRP.

hi5

It's what people are used to, even the Nissan Leaf and Tesla use the format and they don't even have gearboxes as such.

colm_mcm

dr.fuzzenstein wrote: »

Mine used to be LSDNRP.

Were you looking at it upside down?

Eric Cartman

It makes sense, your car is in your driveway in P
Your reverse out R
You go to drive D
You get to work and drive into your space, back up to P , or you reverse into your space, so R , then P .
The N in the moddle isnt commonly used, on older boxes it may have given the gearbox a moment to disconnect rather than going straight from forward to reverse.

Pretty logical layout.

MyStubbleItches

I think having D at the bottom makes sense (in my car anyway) as tiptronic mode is next to it and I'd imagine would be easier to use than having it at the top and left. That said, having tiptronic on the opposite side to the driver isn't great as when I'm doing any spirited driving I tend to pull on the gear selector when going left and end up pulling it back into D.

Indricotherium

Eric Cartman wrote: »

It makes sense, your car is in your driveway in P
Your reverse out R
You go to drive D
You get to work and drive into your space, back up to P , or you reverse into your space, so R , then P .
The N in the moddle isnt commonly used, on older boxes it may have given the gearbox a moment to disconnect rather than going straight from forward to reverse.

Pretty logical layout.

I nearly always reverse into parking spots.

Indricotherium

MyStubbleItches wrote: »

I think having D at the bottom makes sense (in my car anyway) as tiptronic mode is next to it and I'd imagine would be easier to use than having it at the top and left. That said, having tiptronic on the opposite side to the driver isn't great as when I'm doing any spirited driving I tend to pull on the gear selector when going left and end up pulling it back into D.

If the car was LHD would it be on the inside?

MyStubbleItches

Indricotherium wrote: »

If the car was LHD would it be on the inside?

I don't know to be honest but I'd imagine so. It makes more sense.

James Bond Junior

Ive been wondering, what would happen if you put an auto in N at high speeds? Would you need to coast to a stop or would it go back into whatever gear you needed to be in at the speed you are doing?

Eric Cartman

Indricotherium wrote: »

I nearly always reverse into parking spots.

same applies, Drive up , Reverse in , Park , it the most effective layout for most journeys.

colm_mcm

James Bond Junior wrote: »

Ive been wondering, what would happen if you put an auto in N at high speeds? Would you need to coast to a stop or would it go back into whatever gear you needed to be in at the speed you are doing?

Nah, it'd be kinda like pressing the clutch and letting it up again. Can't be good for the transmission, but it wouldn't be dramatic. If you matched the revs reasonably well you could do it smoother. That's on a normal torque converter anyway.

James Bond Junior

colm_mcm wrote: »

Nah, it'd be kinda like pressing the clutch and letting it up again. Can't be good for the transmission, but it wouldn't be dramatic. If you matched the revs reasonably well you could do it smoother. That's on a normal torque converter anyway.

Don't think I'll give it a go either way!!

Toyotafanboi

James Bond Junior wrote: »

Ive been wondering, what would happen if you put an auto in N at high speeds? Would you need to coast to a stop or would it go back into whatever gear you needed to be in at the speed you are doing?

You'l can put an auto in nuetral at any point, as a safety features I suppose.

You have to have the brake pedal pressed to enter reverse or drive so it's not always possible to re-select a gear while the car is rolling.

I can do it in the Honda at times but that is semi auto. If I'm coasting downhill at 15-20kmh I just tap the brake and pop it in to drive and it goes in perfectly smooth. Might be different with a torque converter box.

Cheensbo

Put it in N - plant the boot - drop it into D -

Not sure if that's the correct procedure but it's how i got the auto pajero to do donuts anyway.

The manual ones were waaaaaay more fun to be fair.

Indricotherium

Toyotafanboi wrote: »

You'l can put an auto in nuetral at any point, as a safety features I suppose.

You have to have the brake pedal pressed to enter reverse or drive so it's not always possible to re-select a gear while the car is rolling.

I can do it in the Honda at times but that is semi auto. If I'm coasting downhill at 15-20kmh I just tap the brake and pop it in to drive and it goes in perfectly smooth. Might be different with a torque converter box.

I can definitely put my Honda in d while rolling in N

colm_mcm

Toyotafanboi wrote: »

You'l can put an auto in nuetral at any point, as a safety features I suppose.

You have to have the brake pedal pressed to enter reverse or drive so it's not always possible to re-select a gear while the car is rolling.

I can do it in the Honda at times but that is semi auto. If I'm coasting downhill at 15-20kmh I just tap the brake and pop it in to drive and it goes in perfectly smooth. Might be different with a torque converter box.

Depends on the car.