9 speed gearbox!

[T926_S14A]

Not got any links but on training course I found out that the new (ugly) jeep Cherokee has a 9 speed ZF gearbox, already drove one but never even got anywhere near 9th

Possibly something a few other manufactures will get or may already have/use

[spencer_foxwell]

Why do they need 9 gears? Does that include reverse?

[Stevecarter200]

Must have a seriously narrow torque band to need that many gears. It'll be hard work if its a manual.

[sammos13]

there is thought they will hope on fuel economy cycles due to being able to run a lower engine speed due to being able to spread the ratios... don't be surprised to see 10 speed boxes in the not to distant future

these are auto boxes also

[stevros]

Same box thats going to be release in r/rover evoque. I work in development at jlr and weve been working with it for couple of years now in evoques. Very good box seamless changes you pretty much wouldnt know if wasnt for gear indicator on cluster.

sent from my phone in my hand right now, no now, no now, no now...

[sideways14a]

Why do they need 9 gears? Does that include reverse?

It's ZF's "Fast and Furious" edition gearbox.

[zeppelin101]

Must have a seriously narrow torque band to need that many gears. It'll be hard work if its a manual.

Nothing to do with it, it's just downspeeding the engine at all cruise speeds.

Mercedes have developed their own 9 speed as well to replace the old 7 speeder.

Think VAG are developing a 9 spd DCT too right now?

[T926_S14A]

No that's 9 forward gears, the grand Cherokees 8 speed ZF box is excellent! Bullet proof and awesome in SRT track mode!

[docwra]

The M235i I drove the other day had 8 gears, IS-F did too and they both rev to 8K+. Can never have too many gears, even if only for pub boasting efforts

[Jon]

Wikipedia article:
http://en.wikipedia.org/wiki/ZF_9HP_transmission

I did think the idea of a 9gear auto was ridiculous when I first heard about it, but why not ?
Two or three gears were normal once upon a time where five or six are normal in manual gearboxes these days. and some makes have already had seven and eight speed gearboxes without me noticing.

I understand how four speed conventional auto boxes work, but lost the plot trying to follow the diagrams and examples in the wikipedia article.
Gearboxes will end up like mobile phones. Yes it works, but I don't know how

[docwra]

Quadruple kickdown is a laugh as well

[skyshack]

So how many gears do you need to have the same effect as CVT or IVT?

WOT, engine held at peak power rpm gives best acceleration.

[wutang200]

The 2013 Range Rover has an 8 speed box.

[zeppelin101]

The 2013 Range Rover has an 8 speed box.

All of the vehicles with a longitudinal drivetrain have the 8spd box in the JLR stable.

BMW autos are all 8spd too. Audi may also be using the same box as well? Merc the odd one out as they build all their own transmissions.

[jumpbike]

its all to do with emissions bollocks, the more gears means it can be programmed to stay in the torque curve at the most efficient point for longer therefore is classed as a lower emission vehicle than say the 5/6 speed manual version with the same engine. Also means that some of the lesser well made (usually American) engines will pass modern emission rules

[docwra]

Had an M135i as a hire car in Germany/Austria for a few days last week with 8 speed auto and it does feel like CVT round town, the shifts are seamless and gears are quite short so its pretty much constantly at the same revs. Weird but quite impressive, not quite convinced it would be quicker on track as no clutch robs you of a bit of weight control but the benefit in normal driving might just outweigh that .........