The Automatic Gearbox And Its Failings
Discussion
Fox- said:
cerb4.5lee said:
it does surprise me how many they sell when you consider how noisy and unrefined it is to drive...it can only be the strong MPG and next to nothing VED that wins the day I think.
It offers everything the discerning consumer wants these days.a) A BMW badge on the keyring
b) M SPORT PLUS S-LINE ULTRA badges
c) Very low visible costs like road tax and fuel (They dont care about the hidden costs of motoring)
I liked the ZF6 with my old 330d E90 worked well smooth changes and DS was a lot of fun.
Then I moved to the RS6 which has a 5 speed box its much older tech and is notably slower in gear changes but does start in 1st every time rather than 2nd in the ZF6.
I've tested the BMW ZF8 - wow it is incredible super smooth no hesitation and economical.
Then I moved to the RS6 which has a 5 speed box its much older tech and is notably slower in gear changes but does start in 1st every time rather than 2nd in the ZF6.
I've tested the BMW ZF8 - wow it is incredible super smooth no hesitation and economical.
cerb4.5lee said:
When I had a new 320d as a loaner I was seriously impressed with how little fuel it sipped compared to the petrol cars I have owned so I can see the appeal in that sense but I just wish they could make the engine less noisy and more refined at low speeds because that always left a sour taste in my mouth in what is a £30k car and the engine doesn't match up to the rest of the package for me.
I had a '63 520d M Sport for 3 days - probably one of the very best 4 cylinder diesel car you can buy.I just got the overwhelming impression as I drove it that it was a great car spoiled by the engine and gearbox from something far cheaper.
Fox- said:
cerb4.5lee said:
When I had a new 320d as a loaner I was seriously impressed with how little fuel it sipped compared to the petrol cars I have owned so I can see the appeal in that sense but I just wish they could make the engine less noisy and more refined at low speeds because that always left a sour taste in my mouth in what is a £30k car and the engine doesn't match up to the rest of the package for me.
I had a '63 520d M Sport for 3 days - probably one of the very best 4 cylinder diesel car you can buy.I just got the overwhelming impression as I drove it that it was a great car spoiled by the engine and gearbox from something far cheaper.
From experience but admittedly older models when I owned a 330d and 520d at the same time the difference between the two engines was vast in terms of noise refinement and overall satisfaction and for me a 4 pot in a 5 series shouldn't be allowed!
I got a 14 plate pug 3008 as a hire car (free upgrade 
) that had a 1.6 diesel and a 6 speed auto box in it.
I have no idea what kind of box it was and no real experience of autos but I have to say I was impressed with the pairing. changes were smooth, it seemed to be in a sensible gear all the time, if you planted your foot it dropped a cog or two and did a perfectly decent job of wiggly roads as well.
I'd guess its the same combo youd find in a bini but id be curious to know where else it shows up so I can shop around for a commute car in a year or two ..
) that had a 1.6 diesel and a 6 speed auto box in it. I have no idea what kind of box it was and no real experience of autos but I have to say I was impressed with the pairing. changes were smooth, it seemed to be in a sensible gear all the time, if you planted your foot it dropped a cog or two and did a perfectly decent job of wiggly roads as well.
I'd guess its the same combo youd find in a bini but id be curious to know where else it shows up so I can shop around for a commute car in a year or two ..
This thread has a lot about the degree to which the box in question is in the right gear for the circumstances, and some discussion of change quality, but few apart from cerb have highlighted the major thing I miss about manuals, which is the actual feel through the gearstick of the gears meshing, and being smooth and mechanically sympathetic with the clutch.
Now, my manuals have been from the 90s and 2000s so may well not be so good now as development costs get soaked up by tuning the automatics, but nevertheless I used to love that mechanical feel of nailing a good change. You can't beat it, even if you're not accelerating or braking sharply, it's so, so satisfying if you like mechanical things. You really feel part of the car.
Now, my manuals have been from the 90s and 2000s so may well not be so good now as development costs get soaked up by tuning the automatics, but nevertheless I used to love that mechanical feel of nailing a good change. You can't beat it, even if you're not accelerating or braking sharply, it's so, so satisfying if you like mechanical things. You really feel part of the car.
Fox- said:
I had a '63 520d M Sport for 3 days - probably one of the very best 4 cylinder diesel car you can buy.
I just got the overwhelming impression as I drove it that it was a great car spoiled by the engine and gearbox from something far cheaper.
We have one at the moment as my girlfriend's mini is broken.I just got the overwhelming impression as I drove it that it was a great car spoiled by the engine and gearbox from something far cheaper.
It's still crap as an auto!
Nice to see they've finally sorted out the ride on the F* generation cars though.
Edited by blank on Saturday 19th July 10:15
As others have said, it's more about the combination of gearbox and engine combination than about a specific type of gearbox. For myself, I actually prefer conventional epicyclic autotmatic gearboxes to CVT or Dual Clutch but all can work well in a given setting. I do think all work best when equipped with override paddles or shift lever though, because there are times when you can anticipate better than the gearbox can. It has to be said though in normal i.e. not "pressing on trying to maximise the road speed" driving then most modern automatics cope just fine. You learn to anticipate what the transmission will do and what it won't. Some are certainly better than others for drivability.
I do find that stop start with an auto box actually makes it much harder to get a smooth stop because normally you'd relax brake pressure just as you were coming to a halt. By this time the car has often decided you are going to halt and therefore stops the engine but your release of brake pressure causes it to fire up again providing torque just as you are backing off on the brakes. Much better to have the engine running and the torque as a constant.
I do find that stop start with an auto box actually makes it much harder to get a smooth stop because normally you'd relax brake pressure just as you were coming to a halt. By this time the car has often decided you are going to halt and therefore stops the engine but your release of brake pressure causes it to fire up again providing torque just as you are backing off on the brakes. Much better to have the engine running and the torque as a constant.
One advance which will flow down from rR and Bentley is to link the auto box to Sat Nav so it knows what corners or decents/climbs are ahead.
Autos clearly cannot over rev an engine or labour it. Many modern cars also have rev limits in neutral ie Hinda Civic Type R will not rev beyond 4k revs in neutral and that is a stick shift.
Autos clearly cannot over rev an engine or labour it. Many modern cars also have rev limits in neutral ie Hinda Civic Type R will not rev beyond 4k revs in neutral and that is a stick shift.
ORD said:
I agree that some engines are better with an auto. In general, if an engine has a shortish power band and no character, you may as well get the auto.
For example, the only good thing about the 320d is that it is an auto, which suits its engine extremely well. There would be literally no point in that car with a manual box.
Agree with this, the power band on modern diesels is much better suited to an Auto than it is with a Manual.For example, the only good thing about the 320d is that it is an auto, which suits its engine extremely well. There would be literally no point in that car with a manual box.
ORD said:
I think people overstate the difficulty of driving fast in a manual. In my younger days I barely ever changed up much before the redline and I don't think I ever fluffed a change.
Its definitely easier to drive fast with an Auto IMODodsy said:
The 6 Speed ZF in the XJR is ok, its sometimes poor decision making is overcome by the 400Bhp on tap. What I hate is that it pulls away in 2nd gear unless sport mode is selected. On a light throttle is just crawls out at slow speed , gently push the throttle and nothing, nothing,. nothing *wham* it takes off. Its a well documented problem with the XJR, I dont think they ever mapped the FBW throttle properly. Easily solved by selecting sport mode but that then kills the already rather low fuel consumption.
When I'm driving on my own its fine but with passengers the lumpy / erratic acceleration when pulling out gets annoying so I am constantly turning it on and off.
I never had that issue with my XJR, perhaps the box needed a reset or remap? Second pulled identically to 1st, only noticed one less gear change otherwise seemed the same. First obviously had a bit more urge but that is all.When I'm driving on my own its fine but with passengers the lumpy / erratic acceleration when pulling out gets annoying so I am constantly turning it on and off.
JagXJR said:
I never had that issue with my XJR, perhaps the box needed a reset or remap? Second pulled identically to 1st, only noticed one less gear change otherwise seemed the same. First obviously had a bit more urge but that is all.
This raises another interesting issue with regards to 'learning' boxes and secondhand cars. These boxes learn the driving style of the previous owner. It's even relevant to your car after you've owned it for long enough.
It is well worth resetting the brain on these types of boxes when you buy a used car or just every so often.
With some cars you can do it yourself by following a convoluted procedure, others need a Dealer PC attached.
Well worth Googling to see if its possible as it can remove a lot of irritating issues or at least let the box learn directly from your desired style of driving.
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?
FrankUnderwood said:
How old is the Auto that the OP is on about? New 8 speed is unbelievably good.
Its the ZF 6speed from the E9x 3 series 2006 model, I have the same gearbox in my 330i so its easy for me to say it stinks! well it does in this particular application anyway, agree though everyone waxes lyrical about the 8 speed...but I haven't got the confidence anymore for me to risk spending my own money on buying that one though!! FrankUnderwood said:
How old is the Auto that the OP is on about? New 8 speed is unbelievably good.
I'm still old school and prefer a proper clutch pedal and stick, however I wasn't enjoying it on the M1 traffic yesterday.
Maty
When I drove the ZF8 it changed quicker than I ever could all the time - even in comfort mode let alone sport or sport plus. I'm still old school and prefer a proper clutch pedal and stick, however I wasn't enjoying it on the M1 traffic yesterday.
Maty
The changes are so smooth you'd be hard pressed as a passenger (and frankly also the driver) to tell when a gear has changed.
This work of black magic allows higher mpg quicker accelerations due to faster gear changes and more ratios so keeping it at higher power for longer what's to lose.
Never over rev or to know no owner has ever over revd the engine never laboured the engine too.
I wonder how long it will be before the gearbox and engine management prevent full load or high revs when operating temps and below the correct level to ensure to excessive wear - could result in very very long lasting engines given they are serviced.
cerb4.5lee said:
FrankUnderwood said:
How old is the Auto that the OP is on about? New 8 speed is unbelievably good.
Its the ZF 6speed from the E9x 3 series 2006 model, I have the same gearbox in my 330i so its easy for me to say it stinks! well it does in this particular application anyway, agree though everyone waxes lyrical about the 8 speed...but I haven't got the confidence anymore for me to risk spending my own money on buying that one though!! I am a massive fan of autoboxes, that is until I had a 1.0 Micra auto as a loaner from a garage and owned a 2.0 petrol Accord auto. Neither of those engines produced enough low end torque to compliment an auto gearbox. Previous automatic cars have had engine sizes between 3.8 and 6.6 litres.
redtwin said:
cerb4.5lee said:
FrankUnderwood said:
How old is the Auto that the OP is on about? New 8 speed is unbelievably good.
Its the ZF 6speed from the E9x 3 series 2006 model, I have the same gearbox in my 330i so its easy for me to say it stinks! well it does in this particular application anyway, agree though everyone waxes lyrical about the 8 speed...but I haven't got the confidence anymore for me to risk spending my own money on buying that one though!! Gassing Station | General Gassing | Top of Page | What's New | My Stuff