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Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sat Jun 09, 2018 7:10 pm
by Cloggie
This is to follow-up on a conversation started under “Introductions” but that would fit better here.

My car (2015 BMW 320d) is a traditional automatic (DCT is only on some high powered BMWs). It has an 8-speed gearbox and auto gear changes are very slick indeed. For town driving “D” is indeed good (it also includes stop / start as you might expect) but I often drive with the gearbox in “S” or in the “sport” driving mode. Both keep the revs a bit higher, around 2000/min, and these modes also disable the stop / start so there are no hiccups when driving onto a roundabout for instance. In fact the auto mode is so good that I normally leave it at that.

There are gearshift paddles but I find I need to shift my hands on the wheel to use them (not the 10 to 2 I would normally use but towards quarter to 3) – and it only works when you are more-or-less going straight (or when used a fixed steering grip). [You can always reach for the gear selector to make manual changes – and gear changes should probably be left for the straight bits anyway for stability.] The gearbox also keeps to a low gear automatically when going downhill – but often not low enough where there are speed restrictions.

One option for a more spirited drive is to go “all manual” (I need more practice with this – and with so many speeds to choose between, you do end up doing gear changes quite a bit). An alternative is to use a manual intervention (such as move down a gear) only under certain conditions, such as for down hill stretches. Some windy country roads lend themselves well to the “squeeze and ease” approach (accelerator sense, no brakes) but this is one where I find the auto gearbox often picks too high a gear – and then you end up not losing enough speed when approaching a bend, meaning a touch on the brakes is needed.

I have spoken with a couple of keen drivers with the same gearbox who either never use the manual options, or only sometimes, when they can be bothered! I have not settled on a “favourite” approach yet but I think that with practise, I may go part or all-manual for out-of-town driving (one trade-off to consider is whether to keep the gear changes to a minimum – and let the revs vary more – or use more gear changes, closer to what the auto gearbox would do?) Any other thoughts?

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sat Jun 09, 2018 8:05 pm
by exportmanuk
I have a 2017 220d M sport I find the box very good Sport mode only makes use of gears 1 to 7 pushing the stick left into sports mode is a quick and easy way to hold the gears a bit longer and drops box one gear handy when entering a motorway Changing the rocker switch to sport or sport + changes the throttle response too. I find that for the majority of my driving standard drive is fine but on some nice twisty roads I tend to use the paddles for better timed changes.

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sat Jun 09, 2018 9:36 pm
by kfae8959
What have you got against using the brakes?

David

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sun Jun 10, 2018 2:12 am
by waremark
We have two cars with the zf 8 speed - a superb gearbox. I tend to use auto when in town or following at the speed of traffic, and manual with paddles when using more of the performance. I do not use sport mode - when I want lower gears than regular auto I prefer to have selected them manually before accelerating, rather than have the box kick down as I start to accelerate. And sometimes I like to use the torque with wide throttle openings at low revs; you can only do that in manual mode. I rarely use the paddles other than in manual mode as I like to be in control of when to revert to Drive.

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sun Jun 10, 2018 7:18 am
by GTR1400MAN
Most paddle setups let you override the auto for a while without going out of auto mode. Can you not do that with this box?

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sun Jun 10, 2018 8:03 am
by exportmanuk
Hi On the BMW box yes, works well and if you end up in full manual its easy to just flick the gear stick right to go back into auto.

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sun Jun 10, 2018 8:52 am
by Gareth
GTR1400MAN wrote:Most paddle setups let you override the auto for a while without going out of auto mode. Can you not do that with this box?

The problem with doing this with some gearboxes is the point at which they return to fully automatic mode is variable. I've found the return is generally delayed while the driver is using a significant amount of throttle but, if there is even a slight lift, it might take that as a signal to return.

Some 'boxes appear to also delay the return if there is absolutely no throttle input, which is handy if the desire is to make use of engine braking.

Overall, I'd rather it wasn't making decisions for me, hence my preference for full manual mode. Like waremark, I dislike kick-down. I try to be ahead of the 'box in such situations by having already selected the lowest appropriate gear when I want significant acceleration.



edit: typo

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Sun Jun 10, 2018 9:20 am
by GTR1400MAN
I wondered as it is a facility I make quite a bit of use of on my car (not a ZF 8 speed).

Yes, the return time can be a bit variable on most cars/types of box.

I tend to use the facility to drop a gear or two approaching an NSL, or down a gear when coming into a RAB (where if you are driving with a delicate right foot there is a tendency to hold on to higher gears too long).

For coming down hills and having fun on B roads I always lock into manual mode (and sometimes switch to sport mode for the engine config).

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Mon Jun 11, 2018 12:41 pm
by devonutopia
I can only comment from basis of 2006 335D ownership but I love the box - 6 speed with paddles and S mode, but I usually leave in D and find when braking downhill the box will shift up one, sometimes two cogs, without being prompted to give some engine braking. On more gentle downhills I find just flicking the paddles works fine for maintaining a steady speed when needed.

But its a slightly lazy car to drive and 99% of the time I am just in D. Roadtrip to the alps next week, so might try S around some of those hairpins.

Re: Use of ZF 8-speed auto gearbox (BMW and other makes)

Posted: Mon Jun 11, 2018 8:45 pm
by Discov8
My old RS6 which I've had for 4yrs or so has a 5speed auto with normal, sport and manual modes. Changing gear on the stick shift or paddles which I prefer. Paddles used with hands at qtr to three. If using manual mode the only time I use the stick is pulling out of junctions because you lose the relationship to the fixed position paddles.
In normal auto mode I prefer to shift down manually in the planning of an overtake rather than use kick down, application of 450horses I feel is more controllable. Rarely use auto sport mode, mainly because I prefer manual mode for fun driving.
Best thing I've done to improve the drive with an auto box was to learn left foot braking.