Automatics

[Aspman]

This might seem a stupid question but anyway....

 

How are you supposed to drive an automatic?

 

Until this car I've always driven manual cars, and my whole family has driven manual cars as well. In fact I've rarely been in anything other than a manual car. Two exceptions being a rather awful Chrysler PT Cruiser hire car in USA and a Jag I had as a loaner.

I've never been taught how to drive one.

 

So I get the 335d and they are auto only anyway.

 

It's got R,P,N,D and an option for manual shift (also a manual override in D). The car bible tells you what each does but not when to use them.

I'm not completely daft I know to drive in D and park in P.

 

But...

 

What are you supposed to do at traffic lights?

Leave it in D or shift to neutral?

 

I read that you should do both.

 

If P is for parking WTF is N for?

 

My stop/start only works in D, but then only when a set of 25 criteria is met so quite often is doesn't work.

 

My manual brain thinks "stopped in D it must be burning a clutch", but a torque converter isn't a clutch and it might not be wearing.

 

So I dunno what to do.

[Ryeman]

Long stop and/or v high ambient temperatures  - handbrake and N......Save your brake light globes also.

N enables idling whilst head under the bonnet.....and revving the engine (if it's an old cable type)

 

[Huskoda]

At lights I put mine in N and handbrake on, just as in a manual. Safer and more comfortable. A TC won't burn out when stationary.

 

Never put it in P at the lights because if you get hit from behind you're going to need a new gearbox along with whatever else is broken. Neutral is exactly that. Put it in that if you want to take it out of drive but not lock the drivetrain. Like at the lights as just mentioned or if you are doing maintenance and need to be able to move the wheels.

How much you use the manual overrides is up to you. I frequently tap the paddles when going down hills to hold gears (mine uses the inclination sensor to not go back to D until you level out).

[Aspman]

Yes I feel slightly bad at light because to get the stop/start to work you have to leave it in D and hold it on the brake. I suspect the car actually dims the brakes light but I'm not sure.

 

I only use the manual override prior to an overtake to save waiting on the kickdown, or to knock it down two.

Edited 6 March, 2017 by Aspman

[Ryeman]

Ours stops when the car is stationary having selected N and restarts when D selected.......assuming all the boxes have been ticked

[Aspman]

Quick bit of reading... didn't know that a torque converter is a fluid based thingy, so I'm not burning anything by holding it on the brake.

[Ryeman]

3 minutes ago, Aspman said:

Quick bit of reading... didn't know that a torque converter is a fluid based thingy, so I'm not burning anything by holding it on the brake.

On electronic fuel injection cars, staying in D uses a tad more fuel to overcome the slush drag.

The critical component tends to be the seals which tend to harden with age and higher temps.

[punyXpress]

 . . no mention of NOT leaving it in neutral which doesn't blind the poor barsteward behind ?

[CWARD]

Also driving a BMW F30 8 speed auto with stop start function. Coming to a halt in traffic and so long as the car is up to temperature and the ambient air is above 2.5C the stop start function will operate and so long as you leave your foot on the brake it it will remain off for a set amount of time. After that it will restart itself to prevent damage. If you come to halt in traffic and the engine is stopped by the stop start function but you think you are going to be stationery for a while but the gearbox into P. When the traffic starts moving again put the gearbox back into D and engine starts and off you can go again.

The start stop can be a bit quick sometimes and if you come to halt then press the brake a little firmer and release the additional pressure within a second it prevents the stop start function. Same when you have lot of lock on the steering.

 

Keeping your foot on the brake and in drive won't damage the gearbox, and what a wonderful gearbox it is too. 

[Phil-E]

As you've discovered yes the torque converter is a fluid coupling. So although you're not wearing anything out you are pumping oil around and putting it under pressure which generates heat. Heat is what degrades the oil so lots of idling and hard launches/towing etc can degrade the oil quicker.

 

Your car has a ZF made 8 speed gearbox in case you're interested.

 

If you're stopped for a while it's best to go into neutral. Does your car not have an auto handbrake?

 

N is just neutral like a manual box. No gear engaged.

 

P is the same as Neutral but also the parking pawl is engaged:

 

 

Generally just leave it in D. You will have plenty of power and torque to not have to worry about manually downshifting to prepare for overtakes etc. It will be similar to mine with with the torque on tap. See and gap and just plant it and you're off!

 

Manual mode can be handy for hilly/bendy road driving so it's not up and down the gears so much.

 

And for some real fun... yours should apparently have launch control.

 

Put it into Sport+, move gear selector to M with left foot on the brake. As you then press the throttle a flag should appear on the dash. Floor the throttle then let go of the brake pedal when ready to go!

[CWARD]

1 hour ago, Huskoda said:

Never put it in P at the lights because if you get hit from behind you're going to need a new gearbox along with whatever else is broken.

 

That is the third parties problem who will be paying for the repairs rather than mine for being shunted into the car in front and then having an insurance claim against me.  

[VRS Mike]

ours has auto handbrake, when we stop at lights just come off the brakes and wait for green light, ours also has a coast function which disengages drive when you come off the accelerator, I think they are so advanced now I'd be surprised if there is any clutch wear when stationary.

 

[CWARD]

5 minutes ago, Phil-E said:

And for some real fun... yours should apparently have launch control.

 

Put it into Sport+, move gear selector to M with left foot on the brake. As you then press the throttle a flag should appear on the dash. Floor the throttle then let go of the brake pedal when ready to go!

 

I would do this but tyres are too damn expensive now on my own car but a hire car though

[Aspman]

27 minutes ago, punyXpress said:

 . . no mention of NOT leaving it in neutral which doesn't blind the poor barsteward behind ?

 

It is a concern however the car does appear to be made to work with your foot on the brake. Looking behind the guy isn't illuminated like a Dutch sex worker so I think that the car tones down the brake lights for that purpose.

 

Car has a manual handbrake which was a pleasant surprise, I'm not a huge fan of electric parking brakes.

 

There might be some sort of automatic braking going on when the car is stopped, if I put the handbrake on then release the car seems less prone to creep than just stopped on the brake.

 

For longer stops I had been putting the hand brake on and slipping the car into N but some commentary online was that it was best to leave the car in D. There was more wear done to the gearbox in the change than through sitting on the brake letting the torque converter handle the load.

 

Big warnings on the car RE launch control. I've never felt the need for it, it's silly fast off the line anyway. I'm sure the car will keep track of how many times you use it as an excuse to get out of warranty.

Edited 6 March, 2017 by Aspman

[CWARD]

A few more tips on the stop start and gearbox

[Phil-E]

I wouldn't be surprised about the launch control if it did log it. I know VAG cars do.

 

It's a bit of a faf anyway and just as easy to leave it in D and plant your foot.

 

In my car I can also set off in up to 3rd gear (common across most torque converter autos to aid in winter driving) which can help get going quickly as it cuts out a gear change doing it in 2nd.

 

It will probably have a hill hold kind of function that keeps the brakes on momentarily to help setting off on hills.

[Aspman]

There is no 'snow' mode at all. I had though that "M/S" was "Mud/Snow" but it's "Manual Shift".

 

It's 4x4 anyway so I guess if it won't move then I get out and walk.

[Phil-E]

Yeah it will work fine in D in snow.

 

But you can use manual mode and set off in 2nd/3rd to aid traction when setting off.

 

The old auto boxes with the Mud/Snow mode would just set off in a higher gear automatically and reduce power to the wheels.

 

I guess with X-drive and fancy ESP systems these days there is no need for it.

[KenONeill]

I'd use neutral when I'd use neutral with a manual 'box.

 

P(ark) locks the transmission, and should only be used when parking.

 

Use of manual holds etc is dependent on the individual power train IME.

 

Other stuff - Regardless of what your owner's manual/service schedule says, ZF Transmissions recommend changing ATF every 50_000 miles.

[Phil-E]

Agree with Ken there!

 

All car manufacturers seem to give a long service interval recommendation on auto boxes (think it's about 92k miles on the ZF and was the same for my Aisin Warner box) but the actual gearbox manufacturers give much short intervals (more in the region of 50-60k miles).

 

After seeing the oil that came out of my gearbox after 78k miles I would always do it sooner rather than later!

 

Like I said above the oil is subjected to very high pressures and temperatures especially with high torque diesels which degrades the oil quickly.

[Aspman]

54 minutes ago, Phil-E said:

 

Like I said above the oil is subjected to very high pressures and temperatures especially with high torque diesels which degrades the oil quickly.

 

630Nm, mwahahaha.
TBh the car is quite coddled (and likely always will be), I like the power on tap but feel no need to use it all the time.

 

I suspect when it get close to that time I'll be moving cars anyway

[SWBoy]

4 hours ago, CWARD said:

 

That is the third parties problem who will be paying for the repairs rather than mine for being shunted into the car in front and then having an insurance claim against me.  

Unless the cost of a new auto gearbox increases the cost of the repair enough to become uneconomic (in the view of the insurer), when your car will be written off - which it might not have been if you weren't in P.

[CWARD]

Still the third parties insurers problem to compensate for the my loss.

[SWBoy]

5 minutes ago, CWARD said:

Still the third parties insurers problem to compensate for the my loss.

And then your problem to find a replacement car, they won't help you with that; only pay you cash.

[CWARD]

I think I'd still rather have a car that hasn't been rear ended though, especially if it had been stationary at the time.