[BeantownThinker]

Wow!!! 10 gears in an AT. Amazing!!!

So what's next? 12 gears?

There are excerpts of the article given given here which talks about less stress on the 1st gear and thereby making it more manageable with going over board. It talks of being in the right gear at the right speed while on the track. It also talks of making the car more efficient while on a highway run.

And it also goes on to talk about a few other things. What I am interested to know is what does all this translate to on the ground?

Numerically speaking what is the timing difference on track between this 10-speed AT and say an 8-speed or 6-speed AT?

What is the fuel consumption difference between this 10-speed AT and an 8-speed or 6-speed AT?

I have gut feeling that the improvements will be so minuscule that to have those 2 additional gears will not make any sense.

Don't get me wrong. I am all for advancement in technology. But when someone flaunts something like this, then I am like, "Meh. So What?"

[abhishek46]

Originally Posted by IshaanIan

You don't think the engineers and programmers thought of that? Have you driven a proper 8 speed box? They never fumble about and in most cases are far better than the 7 speed DSG trannys you see on VWs. Secondly, if you read they have managed to keep the gearbox the same size as the 8 speed might weigh a bit more but the wider range of gear ratios overcomes the weight in terms of both performance and efficiency.

There are so many instances of problems (like sudden gear changes, abrupt acceleration and jerky response) with these 8/9 speed ZF units in Hondas, Jeeps, Land Rovers and other Chryslers etc. The internet is full of these issues.

I haven't driven an 8 speed unit. But what's the point? You dont have to drive one yourself to know about issues in these things.
Engineers and Programmers are not gods. They can very well do mistakes, as evident above.

Higher number of gears is not necessarily always better. It depends on the engine characteristics, tuning and engineering. The engine and gearbox are a closely knit unit. If they are not well matched or tuned with good software, it wont help even if you have a 10 or 20 gears!

The real benefit of having a 10 speed or more is when the engine has a very narrow power band. (Like a modern day truck)
In modern day cars where many new engines are force-inducted, the power band is wide. Adding more number of ratios would not make much difference other than when coasting on the highway.

[IshaanIan]

Originally Posted by abhishek46

There are so many instances of problems (like sudden gear changes, abrupt acceleration and jerky response) with these 8/9 speed ZF units in Hondas, Jeeps, Land Rovers and other Chryslers etc. The internet is full of these issues.

What's your point? Those issues are not cause because of having 8 or 10 gears compared to 6 or 7 they are universal amongst all automated systems with more than one clutch including ford's 6 speed DCT and VWs 7 speed DSG.

Originally Posted by abhishek46

Higher number of gears is not necessarily always better. It depends on the engine characteristics, tuning and engineering. The engine and gearbox are a closely knit unit. If they are not well matched or tuned with good software, it wont help even if you have a 10 or 20 gears!

No one said the gearbox in a car is the only important thing or that engine mapping is not important.

Originally Posted by abhishek46

I haven't driven an 8 speed unit. But what's the point? You dont have to drive one yourself to know about issues in these things.
Engineers and Programmers are not gods. They can very well do mistakes, as evident above.

Again, no one said they were gods, but don't you think they have thought about basic arguments that you and I can come up with within 5 minutes of analysis, and worked towards solving them?

Originally Posted by abhishek46

The real benefit of having a 10 speed or more is when the engine has a very narrow power band. (Like a modern day truck)
In modern day cars where many new engines are force-inducted, the power band is wide. Adding more number of ratios would not make much difference other than when coasting on the highway.

The key word here is optimal. Optimal performance and even if there is a wide power-band, you need to look at optimal efficiency even while accelerating considering we don't always have to floor the throttle to gain speed. Efficiency is not solely linked to coasting on the highway.

Try setting lap times on different tracks without the help of engineers and customizable ecu maps. Then you will realize how important having the optimal gear ratio is Ofcourse improvements in performance and efficiency will keep getting smaller and smaller but that is always the case when you pursue perfection.

[abhishek46]

Originally Posted by IshaanIan

What's your point? Those issues are not cause because of having 8 or 10 gears compared to 6 or 7 they are universal amongst all twin clutch systems including ford's 6 speed DCT and VWs 7 speed DSG.

The 9 speed systems above which are used by Honda, Chrysler, Land Rover, Mercedes etc are not Dual Clutch Units.
They are Torque converter Units.
The point is that when you say that the 8/9 speed gearboxes are all great, you are not 100% correct.
They have their fare share of problems. These problems are not any general problems, if you look deeper into the problems, the issues (like abrupt and frequent up shifting and down shifting, jerkiness) are compounded by the fact that there are too many gears.

If you really like having 10 gears on your ride, great! Good for you!

[IshaanIan]

Originally Posted by abhishek46

The 9 speed systems above which are used by Honda, Chrysler, Land Rover, Mercedes etc are not Dual Clutch Units.
They are Torque converter Units.

Thanks did not know that. No idea why torque converters that too in Hondas are not proving reliable, however let us stick to the more relevant gearboxes here. I have seen no more issues in ZF 8 speeds when compared to 7 speed DSGs or 6 speed DCTs

[GTO]

Originally Posted by IshaanIan

So the gear ratios make the transmission very relevant IMO.

Originally Posted by IshaanIan

If you read up properly you will see that even the 8th gear in the GM box, has a shorter ratio than most 6 speed manuals do at top gear

There are pros & cons to every situation. The downside of having too many closely stacked ratios is a gearbox that is continuously shifting. Some of us don't like that. If you do, that's awesome. We'd probably be debating about the same when someone comes out with a 12 or 14 speed gearbox! To me, 6 (max 7) is enough.

The bigger cars needed that extra ratio or two for fuel economy ratings, what with their weight & power in an era obsessed with the environment. If they didn't, they'd be badged as 'gas guzzlers'. As the boss of ZF said, 10 speed gearboxes are more for 'marketing' than any other benefit.

[tsk1979]

Originally Posted by GTO

There are pros & cons to every situation. The downside of having too many closely stacked ratios is a gearbox that is continuously shifting. Some of us don't like that. If you do, that's awesome. We'd probably be debating about the same when someone comes out with a 12 or 14 speed gearbox! To me, 6 (max 7) is enough.

The bigger cars needed that extra ratio or two for fuel economy ratings, what with their weight & power in an era obsessed with the environment. If they didn't, they'd be badged as 'gas guzzlers'. As the boss of ZF said, 10 speed gearboxes are more for 'marketing' than any other benefit.

I have a feeling that these guys are creating a CVT eventually. Like digital volume control. 30 steps mean change appears continuous. Once you have a 20 gear automatic transmission, gear changes will become unnoticeable, and it will be like a CVT while not being a CVT.

That said, there are concepts like IVT
https://en.wikipedia.org/wiki/Contin...sion_.28IVT.29

I think that is the future due to the efficiency achieved. Current hydristers can go 97%
https://en.wikipedia.org/wiki/Hydristor

The surprising thing is that in early 20th century, IVTs were actually used

From Wikipedia

In the early decades of the 20th century, several tractors and small locomotives were built with friction-disk transmissions with an output disk rolling on the face of the input disk. For disks of identical diameter, the effective gear ratio could be varied from 1:1 when the point of contact was at the perimeter of the input disk, to infinity when the point of contact was at the center, to -1:1 when the point of contact was at the opposite extreme. The transmission on early Plymouth locomotives worked this way, while on tractors using friction disks, the range of reverse speeds was typically limited.[7]

[yogeshnagpal]

Originally Posted by tsk1979

I have a feeling that these guys are creating a CVT eventually. Like digital volume control. 30 steps mean change appears continuous. Once you have a 20 gear automatic transmission, gear changes will become unnoticeable, and it will be like a CVT while not being a CVT.

Spot On. This thought crossed my mind as soon as I saw the thread title. Its like a CVT in disguise. Once more closely spaced gear ratios are developed to produce 12-14 speed gearboxes - It'll mimic the CVT, without the rubberband effect, no?

[rohitoasis]

We might have an answer to the discussion in the forum within this video.

Motortrend tests the ZL1 in both 6 Speed Manual and 10 speed Auto guise.

https://www.youtube.com/watch?v=E0amO_lJks8

Video touches on the merits of both gearboxes. But trust me the argument would be least of our concerns between the bellowing tyre smoke and the screaming supercharger whine in this video. Request all to crank up the volume for soulful V8 music.