[thaking]

Hi all, one question: when drivin in city and came to traffic light, do you switch from "D" mode into "N" mode or just holding brake? Ahat is recommmended for ZF automatic transmissions?

[IAmATeaf]

Leave it in D and let the gearbox do its stuff.

[archerz]

Just hold the brake. Autos are meant to be used like that. No need to spend time putting into N then back into D.

Also holding the brake means the brakelights will be on; less likely for someone to hit you from behind. fact.








*80% of facts are made up

[agentorange]

I shift into neutral for a couple of reasons.

First, I learned to drive in the UK and it was a requirement on the driving test in the 1970s. Your car was not going to move at a light for something as stupid as your foot slipping off the brake. We were required to shift into neutral and engage the handbrake. Old habits die hard, but see below.

Second, here in Las Vegas we have the double whammy of loooong traffic light cycles (they drive my buddy from Ohio nuts) and mongo heat in the summer. I just can't bear the thought of sitting at a light churning fluid against the brakes and generating yet more heat.

The difference these days is that I generally hold on the brakes until there is a stationary car behind me. You would think Vegas drivers would be able to spot stopped cars with no brake lights with all the practice they get. We don't have inspections here (only smog) and I barely go week without seeing a vehicle that has no working brake lights.

[losturcos]

sometime N sometime D

[jh_f30]

At a stop, I don't think it makes much difference. Just don't coast in neutral, either coming to a stop or if rolling downhill.

[Sigtran]

If traffic light with relatively short break expected, just keep it in D with foot on brake. If longer stop, like >45sec or more expected, then switch to N to relax the transmission and your foot.

As already advised, never coast in N.

[HighlandPete]

Originally Posted by IAmATeaf

Leave it in D and let the gearbox do its stuff.

And it does... (NIC), Neutral Idle Control 'off loads' the gearbox and TC, by about 90%. All designed to work with the footbrake pressed, engages again as soon as the brake is lifted, ready to pull away.

Clever stuff going on inside the ZF.

[HighlandPete]

A bit of technical detail, particularly for those who worry about any wear issues. Note 'NIC' is designed for continuous duty cycle.

The idle control system is designed to reduce the engine idle torque through the TC, reduce the slip down to something like 10%. While stationary with the foot on the brake, one of the gearbox brake packs (‘B’ in any ZF 8-speed schematic) is released, the brake pack is designed for continuous duty in idle control mode. Some of the gear train therefore rotates, ‘idling’ without output drive. It is quite a simple solution, using parts already in the gearbox.

[thaking]

So still mixed opinions, D or N ?

[HighlandPete]

Originally Posted by thaking

So still mixed opinions, D or N ?

There will always be opinion, regardless of whether something is designed to function a certain way, or not.

The ZF gearbox is designed to be run in 'D'.

[Derek Mc]

I leave it in "D" and the stop start cycle (that so many hate I know I know,,,,) does it's thing too. You can hear that drive is disconnecting when it is idling and I believe too that it is much healthier for the gearbox that the sudden pressure surge through the valve body engaging D and N all the time.