ZF 8 speed automatic

[SteveSRT8]

Hear a lot about how everyone hates these gearboxes.

Here's a list of the companies currently using this gearbox:

Audi, BMW, Bentley, Chrysler, Jaguar, Land Rover, Rolls Royce.

Many more getting it set up for their rides, it can even be a hybrid drivetrain as well. Some of these mfgr's may actually recognize a good thing...

 

[whizbyu]

I understand that Porsche Cayenne Diesel, Audi Q7 TDi, and VW Touraeg have this. Made by Aisin apparently, and supposedly very reliable.

 

[hounddog]

I surly thought ZF manufacturing is who made these.

 

[SwampSurvivor]

Aren't ZF and Aisin competing companies? I believe they both make an 8 speed that isn't the same.

It's not that I don't like it, I juts don't trust that certain manufacturers are going to cheapen it up and make it unreliable.

I also don't see the need for 8 speed automatic. I've driven a few 6 speeds and they spent way too much time trying to decide when to shift.

 

[bourne]

Originally Posted By: Miller88
Aren't ZF and Aisin competing companies? I believe they both make an 8 speed that isn't the same.

It's not that I don't like it, I juts don't trust that certain manufacturers are going to cheapen it up and make it unreliable.

I also don't see the need for 8 speed automatic. I've driven a few 6 speeds and they spent way too much time trying to decide when to shift.


Drive the 2012+ mazda 3 skyactiv 6at. Will change your whole opinion about how good 6 ratios can be.

 

[morris]

sounds like a fix looking for a problem.

 

[Kruse]

Originally Posted By: morris
sounds like a fix looking for a problem.


Or win they need repair, a problem trying to pay for the fix.

 

[SwampSurvivor]

Originally Posted By: bourne
Originally Posted By: Miller88
Aren't ZF and Aisin competing companies? I believe they both make an 8 speed that isn't the same.

It's not that I don't like it, I juts don't trust that certain manufacturers are going to cheapen it up and make it unreliable.

I also don't see the need for 8 speed automatic. I've driven a few 6 speeds and they spent way too much time trying to decide when to shift.


Drive the 2012+ mazda 3 skyactiv 6at. Will change your whole opinion about how good 6 ratios can be.


I have. I guess they have a purpose on very peaky engines.

 

[SteveSRT8]

Originally Posted By: bourne

Drive the 2012+ mazda 3 skyactiv 6at. Will change your whole opinion about how good 6 ratios can be.


And rather than a statement about the superiority of the transmission DESIGN, what is really being touted here by this poster is the transmission's PROGRAMMING. Bravo to Mazda.

Once the software is sorted out to tell the trans what to do the rest is easy. These gearboxes function flawlessly and transparently in many, many wildly different platforms, so you now know that poor shifting is not a trans problem but a programming issue.

 

[SwampSurvivor]

I don't think it's poor programming, just too many gears for the power available.

Truck drivers aren't going to use EVERY one of the 18 speeds when the truck is empty, for example.

 

[SteveSRT8]

Compare the shifting of an Audi versus a BMW. Both use the exact same gearbox above.

In the latest comparo I read in Car and Driver the Audi was a completely different transmission, never hunted between gears and drove transparently.

That's why it's programming. You just don't get it. Do you really think Bentley owners will tolerate any fuss whatsoever? Their 200 mph Flying Spur uses the SAME transmission!

Come with us into the future....

 

[greenjp]

More is better, until you get to the point where it's enough. Then more is just more. See 15+ megapixel pocket point and shoot cameras.

The law of diminishing returns is probably in high gear once you've gotten to 6 speeds. For the typical range of speeds in the US (say 0-85 mph) that's one gear for every 14 mph.

The extra gears probably allow for marginally improved highway MPG by getting lower rpms at given cruising speed. Acceleration improvements are also likely marginal, as any benefit gained by spending more time at higher rpms may be offset by the time lost shifting an extra time or two.

The irony is, as SteveSRT8 is explaining, the programming of these transmissions is extra important, as done wrong it'll really allow the "excess" to shine through.

I'll keep my old fashioned stick shifts. Though there's even a bit of an arms race there, as 6 speeds is the norm and now Porsche is coming out with a 7 speed!


jeff

 

[andyd]

I'm enjoying the 5spd manual in my Ranger, first stick in 25 yrs. But I don't commute in it. Transmissions wont quit. But the more moving parts, little parts, in a passenger car strikes me as a violation of the KISS rule of engineering. Unnecessary expense too. Use advertising to divert attention away from the transmission gears or those goofy wheels.

 

[JHZR2]

To add speeds, you have to add gearing ratios and their respective bearings and support hydraulics. For a given volume, the sizes of all this stuff (bearings most importantly, I guess) need to shrink.

Less bearing, more load from higher power engines = no good.

I fear longevity on 4 speed ATs, let alone these.

A well geared 6-speed MT like in my 135i really cant be beat. Its got a useful enough 2nd gear that its super easy to drive in traffic, and a good 6th gear to get >30 MPG highway with a 300hp vehicle with full torque at fast idle.

 

[Clevy]

I figure with that many gears it would operate similar to a cvt and once an rpm and pedal position established it can work that rpm(torque) to the ground.
I think it would be great for pulling. Get first to 3000rpms and only vary 500rpm or so per shift.
That's where tuning would be key. If it could be set up right what a dream to drive.

 

[hattaresguy]

I don't see a problem with it in expensive cars, but in less expensive cars when it breaks its going to cost a bundle.

I bet replacing that transmission costs $4k, or more...plus labor.

 

[hattaresguy]

Originally Posted By: SteveSRT8
Compare the shifting of an Audi versus a BMW. Both use the exact same gearbox above.

In the latest comparo I read in Car and Driver the Audi was a completely different transmission, never hunted between gears and drove transparently.

That's why it's programming. You just don't get it. Do you really think Bentley owners will tolerate any fuss whatsoever? Their 200 mph Flying Spur uses the SAME transmission!

Come with us into the future....


Those new Bentley's are not that good, over hyped VW's.

Now an Arnage...which cost a lot more than $200k and some change...those were nice cars.

 

[PandaBear]

Originally Posted By: JHZR2
To add speeds, you have to add gearing ratios and their respective bearings and support hydraulics. For a given volume, the sizes of all this stuff (bearings most importantly, I guess) need to shrink.

Less bearing, more load from higher power engines = no good.


Well said.

 

[SteveSRT8]

Originally Posted By: JHZR2
To add speeds, you have to add gearing ratios and their respective bearings and support hydraulics. For a given volume, the sizes of all this stuff (bearings most importantly, I guess) need to shrink.

Less bearing, more load from higher power engines = no good.

I fear longevity on 4 speed ATs, let alone these.

A well geared 6-speed MT like in my 135i really cant be beat. Its got a useful enough 2nd gear that its super easy to drive in traffic, and a good 6th gear to get >30 MPG highway with a 300hp vehicle with full torque at fast idle.


Well said how? Trepidation issues? BMW LOVES this gearbox. It's designed for high power levels from the start.

Did you note this trans is used in 600+ hp engines? It's quite durable as it is fully warranted even at those levels. BMW now uses it across their entire line up.

We are not comparing slushboxes to a good manual, we are talking about how folks hate on mega ratio automatics.

BTW, ZF is developing a 9 speed for the wrong wheel drive econoboxes. Even worse, huh?

 

[SteveSRT8]

Originally Posted By: greenjp
More is better, until you get to the point where it's enough. Then more is just more. See 15+ megapixel pocket point and shoot cameras.

The law of diminishing returns is probably in high gear once you've gotten to 6 speeds. For the typical range of speeds in the US (say 0-85 mph) that's one gear for every 14 mph.

The extra gears probably allow for marginally improved highway MPG by getting lower rpms at given cruising speed. Acceleration improvements are also likely marginal, as any benefit gained by spending more time at higher rpms may be offset by the time lost shifting an extra time or two.

The irony is, as SteveSRT8 is explaining, the programming of these transmissions is extra important, as done wrong it'll really allow the "excess" to shine through.

I'll keep my old fashioned stick shifts. Though there's even a bit of an arms race there, as 6 speeds is the norm and now Porsche is coming out with a 7 speed!
jeff


Jeff, you need to get out more. A recent test of Audi vs. Mercedes vs. BMW had the audi beating both HIGHER powered cars to 60 mph via its superbly programmed ZF 8 speed gearbox. It would not have been close with a 6 speed stick or slushbox. See Car and Driver for the details.

A small note: there is no "time lost" to shifting in a modern slushbox. Forward power is not interrupted to shift. That's why they are undeniably superior in a straight line. They are quickly becoming superior in economy as well.

Note this topic is NOT ABOUT MANUALS. They are still a driver's choice.