The Automatic Gearbox And Its Failings

The Automatic Gearbox And Its Failings

Author
Discussion

bennyboysvuk

Original Poster:

3,491 posts

247 months

Wednesday 16th July 2014
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Unfortunately, I have a car with an automatic gearbox and I realise that a lot of the time it's in the wrong gear or just doesn't feel at one with what the car's doing. Does everyone feel that their auto gearbox is a total compromise and will be in the wrong gear half the time or does everyone override it in certain situations?

e.g. enter a tight slip-road to a dual carriageway from a roundabout and the car will be changing up and keeping the revs low as the corner of the slip-road opens up. I want to get to motorway speed quite quickly, so push the throttle further and it drops down a couple of gears and it's then in the right gear.

Another situation is where it hangs onto a gear too long. e.g. I accelerate around a long bend and because the car thinks it might interfere with traction if it changes up (it's not even close) it sits there with the revs up at 6,000 instead of changing up.

Then there's B-road driving and overtaking, steep hills not long after tight corners etc, where the car's always up and down the gearbox trying to do what's required to get along the road. Progress is far less smooth and the gearbox changes gear maybe 3 times more than is required.

My conclusion is that autos work well in really heavy stop/start traffic and when cruising on the motorway. In all other situations it's compromised.

redtwin

7,518 posts

181 months

Wednesday 16th July 2014
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It is a compromise, but then so is a manual box.

It boils down to which set of compromises are you willing to live with. I am willing to give up some gearbox control in order to have smooth effortless shifting and not have to faff about with a clutch pedal and gear stick.

craigjm

17,908 posts

199 months

Wednesday 16th July 2014
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Can't say I have ever really noticed that in my car

Sixpackpert

4,538 posts

213 months

Wednesday 16th July 2014
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Can't fault the box in the XF. Great bit of kit. Sport mode is brilliant and flappy paddles as standard, though they hardly get used.

jamieduff1981

8,022 posts

139 months

Wednesday 16th July 2014
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Not really. I had an old Rover 620SLi for a while which had that terrible Honda engine and automatic gearbox. Everyone hated the Rover engines which were great and assumed anything Japanese must be better so fauned over the Honda engines but they were crap. That was an asthmatic engine with a drink problem and a gearbox that didn't know its arse from its elbow.

I had a 5-speed auto in my first X-Type. It was fine. No sports car, but I was never frustrated with the gearbox.

The 6 speed ZF in my S-Type has been great. The J-gate is old hat but between that and Sport mode mapping you can easily make the gearbox do what you want it to do. My only gripe if I was being picky is that it won't change in to 6th gear below an indicated 52mph, so if stuck beyond some arse doing 50mph it'll be in 5th gear. Even that is easy to get around by dropping back slightly then creeping forward to 52mph, getting 6th gear and then slowing down again. It'll hold 6th gear down to about 45mph depending on throttle input.

The 8 speed Quickshift ZF in my XF is fabulous. It changes a lot in normal Drive mode, but that's what it's for. 70mph in 8th gear sees just under 1500rpm on the tacho and on Thursday and Friday we averaged 31mph from a 5.0litre supercharged V8 from fairly far north in Scotland to Cambridgeshire. Much of that was down to the gearbox. When hooning the car, it's good enough in Sport mode to be honest, although if that's not enough then the paddles do work properly. The only time the paddles will ignore your input is if the gear you asked for would over-rev the engine which is a disobediance I think I'm fairly happy with!

Otispunkmeyer

12,557 posts

154 months

Wednesday 16th July 2014
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That ZF 8 Speed is a work of art I reckon. Mate has it in his new 320d and its pretty much undetectable when it shifts!

kinghottinger

185 posts

140 months

Wednesday 16th July 2014
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Have to agree with the XF auto-gearbox love. I have the 6 speed and although I'm a fan of manuals in general, in the XFR it really is close to perfect in D mode, and even better in S mode. The flappies work great on top of that too.

It might be more to do with the engine it is tied to though, because the same boxes in the TD4 Evoque and TDV6 D4 are pretty standard irritating autobox fare, the worst bit being the lag when trying to take up the slack after decelerating for a junction/roundabout.

va1o

16,029 posts

206 months

Wednesday 16th July 2014
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I'm not a huge fan of the older torque-converter based Autos but I like my VW DSG 'box very much. Find it much more relaxing to drive than a Manual and it always knows the right gear to be in.

Pan Pan

1,116 posts

126 months

Wednesday 16th July 2014
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Not really a fan of auto boxes , but then it has been a long time since I had a car with this transmission type (slushbox torque converter with no lock) It seems the new ones are every good, and offer options for auto or manual gear change.
The torque converters on the auto`s I had seemed to let the engine rev for ages before that power
was finally delivered to the back wheels, just seemed all too sloppy for me.

FiF

43,960 posts

250 months

Wednesday 16th July 2014
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In all three of the situations described by the OP I would have put mine into what Land Rover call Sport mode and it would have been fine. A gear would have been selected probably one lower than it would have been using in D and it would have not been so anxious to change up. On B roads and twisty A roads this means fewer changes.

Very rarely need command shift.

Major Fallout

5,278 posts

230 months

Wednesday 16th July 2014
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Never had a problem, maybe because I have never driven a small engined auto they have always been 2.8 up.
So it never really mattered what gear it was in.

aeropilot

34,297 posts

226 months

Wednesday 16th July 2014
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bennyboysvuk said:
Unfortunately, I have a car with an automatic gearbox and I realise that a lot of the time it's in the wrong gear or just doesn't feel at one with what the car's doing. Does everyone feel that their auto gearbox is a total compromise and will be in the wrong gear half the time or does everyone override it in certain situations?
There are really good autoboxes and frankly, not so good ones.

You're being far too generalistic.




Matt UK

17,649 posts

199 months

Wednesday 16th July 2014
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I had a 5 series with the ZF 5 speed auto.

On the A roads / motorway where it lived, I think it did a great job.

But on the b-roads it was not as good as the full control of a manual. My wife summed it up well once; 'although I need to be in charge, it feels like there are two brains involved - on the backroads your car feels like riding a horse...'

Pixelpeep

8,600 posts

141 months

Wednesday 16th July 2014
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only had one experience with auto and that was the Honda CVT box which sucked. Big time.

Smooth as silk if you never wanted to make progress otherwise the small amount of power that should have been available was lost in slip/noise.

I am just completing the paperwork for a leased Golf R and i've gone for the DSG box because

1) i've heard great things about them
2) i am getting really fed up with east london traffic lights every 40 metres and constantly having to use the clutch
3) its around 4 mpg better on fuel
4) Most importantly - It's 0.4 seconds quicker to 60 than the manual

You can keep your manual with non PAS and drum brakes. Yes you get more feel but we and our cars spend 80% of their lives on the daily commute.

smile

jamieduff1981

8,022 posts

139 months

Wednesday 16th July 2014
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Pan Pan said:
Not really a fan of auto boxes , but then it has been a long time since I had a car with this transmission type (slushbox torque converter with no lock) It seems the new ones are every good, and offer options for auto or manual gear change.
The torque converters on the auto`s I had seemed to let the engine rev for ages before that power
was finally delivered to the back wheels, just seemed all too sloppy for me.
That description certainly fits the old Honda box I had rather well. It was rubbish.

The new ones really are great though, certainly when combined with big, responsive engines at least. I reckon small engines are always going to be hamstrung by having low or peaky torque outputs and small diesels also add low RPM ranges to play with too so frequent shifts and hunting around for a useable gear is inevitable. They'd be just as naff to drive with a manual, if not moreso so it's unfair to expect an automatic gearbox to transform a car with an engine designed for low CO2 and high MPG into a smooth and strong performer without lots of gearchanges and some delay.

One (anyone, not you specifically) should resist the temptation to exrapolate experience of torque converter automatics from decades ago and conclude that they're still no good now. The market for automatics is so strong now that the technology has come on leaps and bounds.

jamieduff1981

8,022 posts

139 months

Wednesday 16th July 2014
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Matt UK said:
I had a 5 series with the ZF 5 speed auto.

On the A roads / motorway where it lived, I think it did a great job.

But on the b-roads it was not as good as the full control of a manual. My wife summed it up well once; 'although I need to be in charge, it feels like there are two brains involved - on the backroads your car feels like riding a horse...'
That 5 speed ZF was a good 'box in its day but it was being built in the mid 1990s and was replaced in the early 2000s by the ZF6 by most manufacturers. I promise you they are nothing like that nowadays.

thatdude

2,654 posts

126 months

Wednesday 16th July 2014
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My wife's auto box in her 120D (ZF 6 speed i assume) is quite good. It does like you to prod sharply on the chuggy peddle if you want a responsive downshift, but there is the option of manually controling the gear selection should one wish (I do when joining motorways, for example)

Her previous car, a mk 4 golf with an auto, was less clever.

richs2891

895 posts

252 months

Wednesday 16th July 2014
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Deficiently some good auto gearboxes and some poor ones. I find the auto in my shogun irritating, holds gears when should change up, sets off in third when 1st would be better, drops to 1st when 2nd would be fine at junction etc.
Yes the DSG I drove in an Audi was way better, OK different technologies and about 10 years in engineering terms.

simo1863

1,866 posts

127 months

Wednesday 16th July 2014
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Modern Dual Clutch technology is cracking (if you could class that as an auto).

Granted I only ever get to drive new cars but my take on that is that anything German or the more recent Jags by and large have very good autos, especially anything designed to go fast. Nissans are pretty decent too.

Not tried the new Renault auto but previously the French have all been well below standard to me, especially the ones matted to the DS5, 508 and 3008 diesel Hybrids.

Toyota's CVT is an interesting one, gets a lot of criticism but it's designed to be efficient, not get you round a track as fast as possible.

Vauxhalls are really bad too, as are Fords.

irocfan

40,152 posts

189 months

Wednesday 16th July 2014
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surely with an auto just override the damn thing. Going to overtake? Ignore "kick-down" and slip it into a lower gear before making your move, once past change up again. Job jobbed