GM, Ford teaming up for new transmissions

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Nothing wrong with better transmissions, the new 8spd Chrysler is using in the 300 and charger is nice. Friend gets 32 mpg highway in his new Charger with the Pentastar.

Chrysler was smart and worked with ZF om the new 8sp and 9 spd transmissions.
 
anything more than 5 speeds is unnecessary, adds to cost, complexity, lessens durability, and increase purchase and maintenance costs.

The consumer must let the manufacturers know that at some point the excesses must stop.
 
Absolutely not true.

More speeds allows for a wider spread of ratios, increases performance while simultaneously allowing better fuel economy. ESPECIALLY important to smaller motors, or any motor with a peaky power curve. These will have real world torque capacity, something a CVT simply cannot presently give us.

ZF 8 speeds are in Audis, BMW's, Bentleys, etc., and they are extremely durable and efficient.
 
Originally Posted By: antiqueshell
anything more than 5 speeds is unnecessary, adds to cost, complexity, lessens durability, and increase purchase and maintenance costs.

The consumer must let the manufacturers know that at some point the excesses must stop.


I heard somewhere that some 6-speed transmissions had fewer moving parts than the 4 speed transmissions they were replacing. Fewer moving parts means more durable.

And, as Steve points out, CVT's aren't good for holding massive amounts of torque. A properly built many-speed automatic would be a terrific tool to have in a working pickup that saw varied use, such as towing one day and running to a client's 60 miles away the next. Good torque for towing, and good highway fuel economy.
 
Too bad Ford and GM are not developing independently. Getting together kills the kind of innovation that only comes from competition. I will say though, that more speeds will make for smoother driving, smoother more sustained power transfer, and better gas milage too. More speeds is the best direction to go, and from a dependability/cost/performace point of view, there is no different in these categories between a 4 speed and a 10 speed auto tranny.
 
Originally Posted By: SteveSRT8
Absolutely not true.

More speeds allows for a wider spread of ratios, increases performance while simultaneously allowing better fuel economy. ESPECIALLY important to smaller motors, or any motor with a peaky power curve. These will have real world torque capacity, something a CVT simply cannot presently give us.

ZF 8 speeds are in Audis, BMW's, Bentleys, etc., and they are extremely durable and efficient.


Wrong, Steve. More speeds makes for narrower speed ratios; not wider. Not that this is a bad thing....adding more speeds between gear 1 and gear 10 makes for smoother transitions, a better nicer driving experience (and quieter too).

You're also wrong about CVT not being able to "hold torque". The limitation here is not hardware, but software. With the correct chip programming, a CVT can handle torque even better then a conventional tranny because a CVT has more ratios for the programming to dial in.
 
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Originally Posted By: SteveSRT8
Absolutely not true.

More speeds allows for a wider spread of ratios, increases performance while simultaneously allowing better fuel economy. ESPECIALLY important to smaller motors, or any motor with a peaky power curve. These will have real world torque capacity, something a CVT simply cannot presently give us.

ZF 8 speeds are in Audis, BMW's, Bentleys, etc., and they are extremely durable and efficient.


You forgot the cost issue. LOL

As for durability those expensive makes are going to make sure the more complicated units are built a bit better to make them durable. I doubt the case will be the same with pedestrian models. Corners will be cut and reliability will suffer.
 
Originally Posted By: antiqueshell
Originally Posted By: SteveSRT8
Absolutely not true.

More speeds allows for a wider spread of ratios, increases performance while simultaneously allowing better fuel economy. ESPECIALLY important to smaller motors, or any motor with a peaky power curve. These will have real world torque capacity, something a CVT simply cannot presently give us.

ZF 8 speeds are in Audis, BMW's, Bentleys, etc., and they are extremely durable and efficient.


You forgot the cost issue. LOL

As for durability those expensive makes are going to make sure the more complicated units are built a bit better to make them durable. I doubt the case will be the same with pedestrian models. Corners will be cut and reliability will suffer.


Not true because the most dependable vehicles in the world are not those expensive German cars...the most dependable are the "pedestrian" you speak of. And the reason those German 8 speeds cost so much more has little to do with actual costs, and more to do with the fleecing of richer folks.
 
Originally Posted By: lovcom
Originally Posted By: SteveSRT8

More speeds allows for a wider spread of ratios


Wrong, Steve. More speeds makes for narrower speed ratios; not wider.


I don't think you and Steve are saying the same thing. You are talking about the difference in ratio between each gear being closer. He's talking about the overall spread of the ratios being greater, IE, 1st could be 6.5:1 with 10th being 0.4:1.
 
Originally Posted By: lovcom

You're also wrong about CVT not being able to "hold torque". The limitation here is not hardware, but software. With the correct chip programming, a CVT can handle torque even better then a conventional tranny because a CVT has more ratios for the programming to dial in.


Then why do we not see them used in transport truck applications? (honest question, I'm not trying to be obtuse).
 
Originally Posted By: SteveSRT8
Originally Posted By: Rick in PA
The 9-speed transmission gave me a chuckle, but I understand, they want to keep the engine in the power band for fuel economy. The chuckle was from remembering the old slip-'n-slide Power Glide, 2 whole speeds, woo hoo.
laugh.gif



Yeah, I remember when 4 speed autos first arrived. The exact same hoo-hah ensued!

Some things never change. It is to be expected that there will be programming issues as mfgrs learn to apply the tech.


They may have been considered a dumb idea for V8 and large 6 cylinder engines, but it was a major breakthrough in 4 cylinder cars.
 
I really have a hard time believing that 10 gears will save fuel.

Yes, I clearly understand that operation at low and efficient RPM's improve economy. However, The BSFC curve of an internal combustion engine does not change much over modest RPM spreads. If a 5 speed transmission drops 700RPM per shift at the mid point in the RPM curve, and only 350 at lower RPM, what's the potential savings? Not much under normal conditions.

We have CVT's that are 100% capable of not shifting, and holding an engine at peak BSFC. Yet these vehicles don't provide significantly better MPG's, if at all.

I rent Nissan Altima's regularly. With me driving normally, they achieve about 26MPG. Not much different from the 26MPG's I get in a Camry 4cyl, or the 26MPG's I get in a Chevy Malibu 4 cylinder.
 
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You know how it is. Automakers will go to great lengths to save 1 mpg even a few .10's. They can get the few mpg increase and a performance increase. Drvability being as good is another argument. I don't have the exact figures but you have to think that once you get over 5 or 6 speeds there are diminishing returns. I think it's partly marketing and wow factor.
 
Originally Posted By: lovcom
Originally Posted By: SteveSRT8
Absolutely not true.

More speeds allows for a wider spread of ratios, increases performance while simultaneously allowing better fuel economy. ESPECIALLY important to smaller motors, or any motor with a peaky power curve. These will have real world torque capacity, something a CVT simply cannot presently give us.

ZF 8 speeds are in Audis, BMW's, Bentleys, etc., and they are extremely durable and efficient.


Wrong, Steve. More speeds makes for narrower speed ratios; not wider. Not that this is a bad thing....adding more speeds between gear 1 and gear 10 makes for smoother transitions, a better nicer driving experience (and quieter too).

You're also wrong about CVT not being able to "hold torque". The limitation here is not hardware, but software. With the correct chip programming, a CVT can handle torque even better then a conventional tranny because a CVT has more ratios for the programming to dial in.


Obviously you misunderstood my post. The primary benefit to a CVT is the ratio spread is wider from lowest to highest.

And they DO NOT handle torque well at all. They require vast amounts of extra programming to limit torque in even a V6 application. You will never see them in any decent performance car without some sort of tech breakthrough that does not currently exist.

Try again...
 
Originally Posted By: Cujet
I really have a hard time believing that 10 gears will save fuel.

Yes, I clearly understand that operation at low and efficient RPM's improve economy. However, The BSFC curve of an internal combustion engine does not change much over modest RPM spreads. If a 5 speed transmission drops 700RPM per shift at the mid point in the RPM curve, and only 350 at lower RPM, what's the potential savings? Not much under normal conditions.

We have CVT's that are 100% capable of not shifting, and holding an engine at peak BSFC. Yet these vehicles don't provide significantly better MPG's, if at all.

I rent Nissan Altima's regularly. With me driving normally, they achieve about 26MPG. Not much different from the 26MPG's I get in a Camry 4cyl, or the 26MPG's I get in a Chevy Malibu 4 cylinder.


While I agree that in real world driving the benefits may be small, the justification for CVT was always a wider ratio spread from top gear to lowest gear. More ratios allows for better performance AND better economy.

Obviously some mfgrs do not think CVT's are where the future lies...
 
Originally Posted By: Nate1979
According to fueleconomy.gov the fuel economy savings for CVT are 6%:
http://www.fueleconomy.gov/feg/tech_transmission.shtml


Over a CONVENTIONAL 4 speed automatic with locking converter. NOT 6% better than a 6 speed automatic. In fact, I see NO real world improvement with CVT's over 6 speed auto's.

I stand behind my statement. A 10 speed automatic is not necessary.
 
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