The Automatic Gearbox And Its Failings
Discussion
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.
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.
Sheepshanks said:
I'm not sure what the problem is in that example - the autobox isn't psychic. Is this your 330i? I'd have thought that would get up to speed pretty rapidly without needing to boot it.
I do think autoboxes work well with turbo-diesels as they mask the limited rev range, and the diesel's torque will pick the car up from pretty well any speed in any gear once rolling - although I'd have thought a 330i would be good at that too. The only time I drive petrol autos any distance is in the US and they do seem more uncertain about what they're doing.
Yes, the 330i needs more than 5k rpm showing to produce meaningful acceleration. It can do the pottering about stuff reasonably well, but I only potter if I'm feeling exhausted. Between the two cars I currently own, I much prefer the 120 diesel with a manual 'box compared to the 3 litre straight 6 3-series with an auto.I do think autoboxes work well with turbo-diesels as they mask the limited rev range, and the diesel's torque will pick the car up from pretty well any speed in any gear once rolling - although I'd have thought a 330i would be good at that too. The only time I drive petrol autos any distance is in the US and they do seem more uncertain about what they're doing.
In my example, it's not really the auto's fault for changing up as it did, but more that it just isn't suited to that type of road at all and will therefore always select the wrong gear.
DonkeyApple said:
However, a couple of the OPs issues are really down to driver misjudgement. The box can't predict the road ahead (apart from in a Rolls) it can only read the current data and make a descision. There are times when you know that these conditions are going to change quicker than the box can work out so you have to take control. Joining slip roads off roundabouts going uphill is a classic. You know exactly what is about to happen and what needs to be done but the gearbox has no data on how long the corner is, how steep the gradient is or that you now need to go from 30 to 70. It knows non of this and so you must take control by starting your exit from the apex by putting the car in the right gear yourself. So typically that means manually notching down a gear or two to find the bottom of the torque curve going into the start of the corner etc.
Quite right. I think I get more frustrated by these things than other drivers might too, hence my post. I do use the manual shift quite often, but I find on my 12 mile commute that I'll slip the box into manual mode on probably 5 occasions in maybe 20 minutes of driving...which probably suggests that I should have chosen a manual as the auto isn't really suitable for my needs. Oh well, live and learn.bennyboysvuk said:
Quite right. I think I get more frustrated by these things than other drivers might too, hence my post. I do use the manual shift quite often, but I find on my 12 mile commute that I'll slip the box into manual mode on probably 5 occasions in maybe 20 minutes of driving...which probably suggests that I should have chosen a manual as the auto isn't really suitable for my needs. Oh well, live and learn.
Sump said:
You're overcomplicating this! You don't know how to drive with an auto. Give it some time and you will learn...
I know how the auto responds though if I leave it in drive. I could change my driving and just ignore all the pointless up changes and down changes that the gearbox makes, but that's wrong in my mind.
Mr Will said:
We're not asking you to ignore them. A small amount of attention to where your right foot is should let you predict and control them. e.g. "If I back off fractionally less here, the box won't shift up so won't have to shift down again ten seconds later". It becomes instinctual after a while.
That's not how my gearbox seems to respond. If I kept the required amount of throttle on to keep it at medium revs 3-4k for the next piece of driving then the car will be accelerating enough to make the car understeer and the DSC kick in around the current bend. Donkey Apple is completely correct in that the BMW gearbox seems to try to be clever and ends up being frustrating because of it.JagXJR said:
bennyboysvuk said:
Quite right. I think I get more frustrated by these things than other drivers might too, hence my post. I do use the manual shift quite often, but I find on my 12 mile commute that I'll slip the box into manual mode on probably 5 occasions in maybe 20 minutes of driving...which probably suggests that I should have chosen a manual as the auto isn't really suitable for my needs. Oh well, live and learn.
Why does it? You use both manual and auto mode, an autobox has both. A manual has only one mode. Sounds like you bought the right box to me. 
Perhaps the choice of car was the wrong decision?
I did absolutely buy the wrong car. Like M-Sports of old, I was hoping the car would be a good deal more fun than it is.
DonkeyApple said:
I'd certainly never have a diesel manual. Totally pointless. You watch people in manual diesels and the frequency at which they are changing gears is farcical.
That said, I'd far rather drive my 120D manual than my 330i auto. It's so much more rewarding to drive. If I could just swap the engines over, I think I'd be happy (ish).Riff Raff said:
bennyboysvuk said:
The manual mode is like driving on a computer game, the engine is barely audible, there's no vibration or feedback at all through the gear lever and I end up looking at the dash to tell what gear I'm in. Not only that, but it changes up on its own at the redline. The manual mode does allow me to let the car know what gear I want, but it's not very interactive compared to a proper manual 'box.
I did absolutely buy the wrong car. Like M-Sports of old, I was hoping the car would be a good deal more fun than it is.
And this is a bad thing?I did absolutely buy the wrong car. Like M-Sports of old, I was hoping the car would be a good deal more fun than it is.
cerb4.5lee said:
bennyboysvuk said:
That said, I'd far rather drive my 120D manual than my 330i auto. It's so much more rewarding to drive.
I am the same and I didn't think the manual in my old 520d really suited the engine much at all but now I have my 330i auto I am at the point where I would pretty much prefer to drive anything else just for a manual gearbox.I mentioned a few months back that I hired a transit van and it sounds mad but I enjoyed driving that more than my 330i purely based on its gearbox so that gives you a good idea how much more enjoyable I actually find a manual.
bracken78 said:
I find this comment very interesting. We have a 330i auto (2006) and a 120D manual (2005) and I much prefer the 330i auto to the 120d for the daily grind as it much more relaxing. If you want fun then to me neither the 330i (manual or auto) and 120d (manual or auto) can be called fun but that is a personal point of view.
Fun for me is high revs, N/A, petrol and manual.
Our 330i auto (ZF) has been perfect expect for a leak which needed fixing. It changes up and down as required and is smooth.
To me an auto is what it is, a more relax way to drive on our busy roads.
This goes past the automatic debate I guess. The 330i has more grip and far more irritating driver aids so it's really easy to go quickly without really noticing, which in turn doesn't really raise the pulse. Not only that, but when it does slide, it's very understeery, whereas on corner entry the 120D handles a bit like a Clio 182. Together with cog-swapping manually, heel and toe downchanges, holding it in gear, knowing it won't change up mid-slide etc, it's hugely more involving to drive than the 330i. I chose the 330i because my old sport BMWs were fantastic and I needed an estate car. This one can't hold a candle to those older cars in the fun department.Fun for me is high revs, N/A, petrol and manual.
Our 330i auto (ZF) has been perfect expect for a leak which needed fixing. It changes up and down as required and is smooth.
To me an auto is what it is, a more relax way to drive on our busy roads.
I do agree with fun being high revs, N/A and manual 'box and if I could have my own car to commute in (my commute is 50% empty dual carriageways with empty roundabouts and empty twisting NSL B-roads) it would be neither of these cars. I really do need an estate car though and for what I want, there's really extremely limited choice.
Welshbeef said:
I guess the Auto haters are about /relatively soon to hit a reality check when we have fully electric cars like the Tesla S being the norm - there will be no stock shift options all auto and all 1 gear.
F1 is auto only
Le Mans auto only
V8 series auto only
WRC auto only
Most Ferraris Auto only - anyone auto haters going to turn down a 458 Speciale as its auto only?
I'm an auto-hater, happy to be driven in an auto or even to use it on the motorway, but otherwise I prefer a manual. I'd turn down the 458 Speciale in favour of a GT3-RS or if money allowed, a Zonda.F1 is auto only
Le Mans auto only
V8 series auto only
WRC auto only
Most Ferraris Auto only - anyone auto haters going to turn down a 458 Speciale as its auto only?
ORD said:
The rear wheels on my car will spin and spin with an appropriately ham-footed application of throttle. Not sure what a manual clutch has got to do with that. It's more about the power/traction relationship and how intrusive the settings for the electronic driver aids.
My car is hopelessly over-tyred and thus has way more traction than power to overcome it, even in first gear. Even in 2nd gear mid-corner when leaping on the throttle with all driving aids off the rears don't slide, the front just pushes wide instead. It's horrible. Having driven cars with less power, similar grip and a manual gearbox and clutch I can confirm that it's way easier to light up the tyres with a manual, whether going in a straight line or not.redtwin said:
bennyboysvuk said:
My car is hopelessly over-tyred and thus has way more traction than power to overcome it, even in first gear. Even in 2nd gear mid-corner when leaping on the throttle with all driving aids off the rears don't slide, the front just pushes wide instead. It's horrible. Having driven cars with less power, similar grip and a manual gearbox and clutch I can confirm that it's way easier to light up the tyres with a manual, whether going in a straight line or not.
Pity you are so far away, I would gladly show you how to easily light up the rear tyres with an autobox. If "over-tyred" means you have drag racing slicks fitted then it won't be so easy, but it can still be done. It has Michelin PS2 in 255/40-18 size on the rear. What did you have in mind to spin them? In the dry, everything I've tried has failed. Due to the hopelessly weak rear ARB, the inside rear won't even spin when I give it a huge amount of throttle and throw in a turn of the steering wheel too. The only way to get the rears spinning is to drive in the wet, which is actually when the car drives at its best and is slightly more interactive.
Spinning the rears in a X63 Merc (apart from the ML) is normal, but in the above car, it just won't happen...which is a world away from previous model M-sports.
As Lee said, the ability to control how the power is applied to the driven wheels and everything that goes with it gives the driver a fantastic amount of options (good and bad), which add up to give more control. e.g. Popping the clutch in a GT86 to get a drift started.
Kawasicki said:
If you corner at the peak of what the car can achieve, then apply full throttle, your 330i spin the wheels.
No, it won't. Do this and usually the front slides wide. I will confirm that next time I drive it though, which is fortunately very little at the moment since I've been commuting on the R1.ORD said:
I laughed at the comment re BMWs. The fawning over the current 3-series is almost funny. Without the M Sport suspension, it has far worse handling than any recent car that I have driven (including some very mediocre hatches).
BMW changed their age old front suspension design for the E9* series and it seems that when pushed hard, the bushes deflect to give almost positive camber on the outside front wheel, which exacerbates the understeer issue further when you need it least. The E9* M3 uses a solid bush so feels much better.cerb4.5lee said:
jamieduff1981 said:
As I have some genuinely powerful cars, enjoyment for me is more about getting as much throttle opening as possible WITHOUT spinning the wheels
I have said many times on this thread how much I hate the auto in my 330i but what I will say is its the only RWD car I have owned where you can use full throttle in the wet or dry in all gears and it just grips and goes and never ever loses traction, it is terribly boring but I take my hat to it with how balanced it is and how the auto obviously plays its part as it delivers the power in a very calm way.Drive my old manual 200sx/z4m/m3/cerb in the wet full throttle and a tree/lamppost/field awaits but the 330 will just grip and go with zero fuss so I suppose it deserves some credit in that situation.
As for our 330is, I'm not sure I'd call them balanced, it seems that BMW did absolutely everything they could to ensure the rear wheels never lose traction, ever.
cerb4.5lee said:
I didn't think it was possible Ben but I certainly think you hate yours even more than I do!
You may be right. I wrote a list earlier with 23 items on it that annoy me about the car. They're nearly all things that probably wouldn't frustrate anyone that didn't have an interest in cars though. I really feel that a Mondeo for half the price would do just as good a job as the 330 and possibly better it in the handling department.E65Ross said:
I'm really surprised that even in 1st gear in the wet a 330i won't spin it's wheels. 2 reasons.... I know for a fact (having driven one) an E46 330i auto will, and my old man used to have a Merc CLK350 cab which had a 7 speed auto and 272bhp and that would also quite easily spin the wheels up. I can't see why the 330i wouldn't. My 745i can quite easily set the traction control light flickering, sure it has more power but it's got 275 section rear tyres and it's a big old b
d to move as well.
You're honestly saying that if it's wet and you are crawling along in 1st gear and nail the throttle it won't spin the wheels? If that's the case, are you therefore saying that it will accelerate at an identical rate in the wet as in the dry? In theory, I suppose you must be?
The next time an opportunity comes to try it I'll give it a go on a few different surfaces and post my findings. In the wet in the Z4M it was epic and if the DSC was left on the light would flash continually from standstill to the top end of third. The 330 feels nothing at all like that. I have to say that it feels like the gearbox feeds the power in so that it does so very gently initially in order to transfer some weight to the rear for improved traction, before allowing any further torque through. It's almost like turbo-lag - my worst nightmare!d to move as well. You're honestly saying that if it's wet and you are crawling along in 1st gear and nail the throttle it won't spin the wheels? If that's the case, are you therefore saying that it will accelerate at an identical rate in the wet as in the dry? In theory, I suppose you must be?
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