9-speed automatic transmission

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More speeds gets the combined fuel economy up there as manufacturers struggle to eek out more efficiency to comply with government regulations. Better than a CVT setup, but fastly approaching rube goldberg status.
 
I don't think you even need 9 speeds in a 4cyl wheezebox. 3 speeds + overdrive is good enough.

Whats even crazier is that Honda is patenting an 11 speed triple clutch transmission. I can't imagine that being coupled with a weak 4cyl motor.
 
And to think, both of the vehicles we drive on a daily basis have less than half the number of gears...

I think 5 or maybe 6 is the most gears you actually "need." Any more than that and it would just get annoying with the constant shifting.
 
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Originally Posted By: Chris Meutsch
The new 9-speeds are the main reason Honda/Acura's reliability numbers are dropping.
Can you provide supporting information for this claim? At least I have not heard any reliability issues with the 9-speed transmission. Albeit, they are probably still new. Honda transmission and reliability are usually not used in single sentence :-)
 
Originally Posted By: Anduril
And to think, both of the vehicles we drive on a daily basis have less than half the number of gears...

I think 5 or maybe 6 is the most gears you actually "need." Any more than that and it would just get annoying with the constant shifting.


Exactly! If the God had intended more than 5 speeds, she would have put more than 5 fingers on a hand.

Seriously; I have driven 6-speed manuals and preferred 5-speed experience.
 
Originally Posted By: Vikas
Originally Posted By: Chris Meutsch
The new 9-speeds are the main reason Honda/Acura's reliability numbers are dropping.
Can you provide supporting information for this claim? At least I have not heard any reliability issues with the 9-speed transmission. Albeit, they are probably still new. Honda transmission and reliability are usually not used in single sentence :-)


http://www.consumerreports.org/cro/honda-pilot-road-test.htm

There are some more articles talking about this ZF unit causing major problems in the Jeep's that they are in, but fewer Honda's/Acura's so perhaps software updates have fixed the issues for the most parts in the Honda's.
 
Honestly I don't think most of these small gas engines have enough torque to benefit from all those gears. I'm with HosteenJorje on this one.
 
Makes sense to dial in the about-perfect gear for the situation. Paradoxically, the number of moving parts in one of these high-gear-count boxes is fewer than the number in a 4-6 speed auto. That should be more reliable, all things considered. And, the wear is spread out over more clutch packs, so that should also make it more reliable.
 
Originally Posted By: Vikas
Originally Posted By: Anduril
And to think, both of the vehicles we drive on a daily basis have less than half the number of gears...

I think 5 or maybe 6 is the most gears you actually "need." Any more than that and it would just get annoying with the constant shifting.


Exactly! If the God had intended more than 5 speeds, she would have put more than 5 fingers on a hand.

Seriously; I have driven 6-speed manuals and preferred 5-speed experience.

Wife still drives a 3 speed auto all the time. And yes, I wish it had an extra gear or two. But not 6.
 
Wouldn't you need a higher stall torque converter for these 6+spd automatics so the transmission can stay in gear within the engine's powerband? I can see using more gears plus a well spec'd torque converter so the gear changes are within the engine's powerband to deliver power more efficiently.
If it's to keep the revs low for fuel economy why not use a low stall torque converter and a 5-6spd auto?
 
Originally Posted By: Chris Meutsch
The new 9-speeds are the main reason Honda/Acura's reliability numbers are dropping.


Honda had problems with 4 speed automatics. Don't believe me look around for all those people with 6th generation Accords.
 
Originally Posted By: demarpaint
Honestly I don't think most of these small gas engines have enough torque to benefit from all those gears. I'm with HosteenJorje on this one.


I believe it's the other way around. More gears, larger ratio between highest and lowest gear, means they can use a lower torque motor. They can just rev the engine up and then use torque multiplication to obtain whatever torque level is required for the task at hand.

Originally Posted By: Kibitoshin
Wouldn't you need a higher stall torque converter for these 6+spd automatics so the transmission can stay in gear within the engine's powerband? I can see using more gears plus a well spec'd torque converter so the gear changes are within the engine's powerband to deliver power more efficiently.
If it's to keep the revs low for fuel economy why not use a low stall torque converter and a 5-6spd auto?


No, these days they are using lock up convertors and leaving them locked under more conditions. Unlocked convertors all have some amount of slippage, and create waste heat--heat is a form of loss, thus reducing heat is a way to increase mpg. Stall speed is really only needed for getting the vehicle going; letting the engine rev up into its power band so to get moving. Once moving though it's something a handicap (extra weight, slippage). I don't think stall speed is a variable worth playing with--just make it high enough for the engine to launch the vehicle, and count on lockup for the rest of the time.
 
Originally Posted By: Errtt
Seems gone are they days of straight 6 with 3 on the tree


A true story will demonstrate. When Larry Bird was signed out of college by the Celtics (about 35 years ago) he got as part of the deal, the Celtics to agree to purchase his mother a pick-up truck to her specs. She wanted a Ford pickup with a 3 on the tree. The only problem was that they had stopped making them by that point. Ford was able to retro fit one for her, and that maybe the last one Ford ever made.
 
Originally Posted By: KGMtech
As AT's add more gears, as what point do we call it continuously variable? I know that lots of people think CVT is something akin to Leprosy....but is this move to 7,8,9,10 speed transmissions just the same deal only sliced differently?


As long as there's no big torque loading involved. CVT's have an issue with any real power.

Everyone critical of the 8 and up speed trans should consider the words "ratio spread". This is why I can spend all day running errands in my Wife's RAM and get 19.5 mpg with a 395 hp engine under the hood.

The 8 speed ZF slushbox is used in many brands like BMW, Jaguar, etc. Bentley even buys it, and their AWD cars have monstrous power plants.

The only real issues these transmissions have displayed are programming, not trans design.
 
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Originally Posted By: demarpaint
Honestly I don't think most of these small gas engines have enough torque to benefit from all those gears. I'm with HosteenJorje on this one.


It's the big torque engines that don't need many gears though. The little engines benefit from more gears, to keep the torque at the wheels at it's highest potential.
 
Originally Posted By: Jetronic
Originally Posted By: demarpaint
Honestly I don't think most of these small gas engines have enough torque to benefit from all those gears. I'm with HosteenJorje on this one.


It's the big torque engines that don't need many gears though. The little engines benefit from more gears, to keep the torque at the wheels at it's highest potential.


True but the big torque diesel trucks use a lot of gears to make speed since they can't do it via rpms. It's the low torque high rpm engines that are forcing these 9 speed transmissions to constantly up and downshift and hunt for the right gear. With more torque coming from the engine that engine transmission combo would benefit greatly, and not downshift because of a slight incline or strong headwind.

Keep in mind I'm not talking about a 400hp hemi application. I'm talking 4 and 6 cyl. passenger cars and SUV's.
 
Issues with Hondas 9 speed in the pilot kept me from buying one.
She wanted the Touring package.
There were less equipped models available with the 6 speed.
 
Sometimes it just seems like auto makers want to see who can have the most number of gears in their transmissions, like it's some sort of bragging rights or something...do we really need 9 speed transmissions?
 
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