GM's 8 Speed Automatic is in the Works

[redimpss5]

MMMkay!

[zabolots]

Originally Posted by Z16monte

Lock up torque converters do this already, with the advantage of torque multiplication while accelerating. They tend to unlock to readily though.

Yes, but IIRC lock up torque converters only lock up in top gear while crusing while a DCT gives the direct connection in all gears at all times.

[Dgrocho]

Stupid

Do we see a trend now? obviously the race is to see who can have the most gears tweaked the best blah blah blah blah. Each increase in gear ratio is a huge development cost for ever diminishing returns. The main focus should be on perfecting CVT's. They're just all around better, and their only real problem is that it feels slower than something that shifts, when in reality a CVT is faster and I'm pretty sure more efficient. So, we simply develop better and better CVT's, staying out of the gearing game, and just program in artificial shift points so people remain happy. This increased gearing crap is just marketing, there is already better technology available.

[milnersXcoupe]

If GM doesn't produce an 8 spd. automatic - I'll get an Adapter kit - install the ZF unit.

It's beyond comprehension that GM ignored transmissions in their quest for performance and fuel economy.

When is more too many ?

ZF has squeezed another 11% efficiency out of the 8 spd.

If GM geared one effectively, you'd snick 7 turbine like gears landing @ 65mph in 8th.

The engine would run in a 'sweet spot' power band delivering the best Torque and Economy.

With the coming Electric Hybrids - all I'm hearing are one and two speed Transmissions..
this GM 8spd. may never see light of day.

If I were Lutz, I'd cut a contract with ZF to produce the 8spd. in the USA.

[Stéphane Dumas]

I wonder if GM will built it in a joint-venture with Ford like the current 6-speed for FWD vehicules and/or Chrysler?

[milnersXcoupe]

Would make perfect sense - then they'd have 6 spds. in the econo cars & 8 spds. available right now for the V6 / V8 without the specialized development tooling expense.

ZF may end up in Lexus / Toyota should economic trends continue.

The future of all this technology depends upon a Boone Pickens style plan where Natural Gas is used for Heavy Transport - with LPG being the fuel for private vehicles / Hybrids.

LPG is a by product of processing Natural Gas.

Currently LPG is $2.00 Gal. - Australia moved all their transport to LPG from Natural Gas.

If Washington cures the structural flaws of our Energy Sector - exporting our Coal to World Markets to be bid up - same with Natural Gas, the Transport sector could make a less traumatic transition to Hybrid Electric.

Either way, an 8 spd. Automatic will land in my junkyard '66 GTO convertible - with a someday blown Cadillac powerplant.

[big swede]

Talk about bringing a thread back from the dead. I have been a proponent to 6 speed autos way before they were commonly accepted by most but I think adding DSG will help add more efficiency to the transmission than throwing another two gears at it.

If you want to design a new transmission based on DSG technology and the you want to add a couple of more gears lets talk but to spend millions in development cost just to go from 6 to 8 gears, no thanks.

[crazyjkz]

I'm all for an 8-speed auto at least for Cadillac to compete with Lexus/Mercedes/Infiniti 7 and 8-speed autos, but their's no reason that GM should be spending any unnecessary money/time/resources in developing a new 8-speed until ALL of their outdated 4-spd autos are finally phased out by their new 6-spd autos.

[milnersXcoupe]

Well designed 6 - 7 - 8 spds. required little changed to accommodate the additional gears - fact.

GM underestimates the buyer climate - which costs them repeatedly.

Anything GM that can use a 6 or 8 spd. transmission should get one.

Transmissions should not be Prestige Items in this world of $4.00 Gal. Fuels.

Yes, at the beginning of the 6 / 8 spd. introduction, the first ones off went to Top of Line Vehicles obviously: Lack of production numbers / opportunity to combine intro's .

However - those pagent days are over.

The public read of 5 & 6 & 7 & 8 spd. automatic transmissions - the benefits of response / economy.

GM chooses a bean counter approach to production:

"..use up available 4 spds. first.."

Then they're panned badly in the Press, stock takes a hit & wonder why ?

In this Economic Crisis climate:

- the remaining 4spd. Automatics should hit the recycle bin first.

Make policy to install 6 spd / 8 spd in anything leaving GM, make this known to the Automotive Press and why.

As much as I like buying GM / American:

Folks, there is no way I will buy any car sporting a 4spd Automatic Trans. and neither will many other car shoppers.

Buyers need crisp smooth quick transmissions that don't require engine's to haul rpm up over wide RPM bands like a cement truck - which costs fuel - hence the advent of multiple gear transmissions.

[AMcA]

Think of it this way: an eight speed, if they can simplify it and make it cheap enough to build, is going to get you a few percent more mpg. And GM needs every mpg it can get.

So if it doesn't cost too much, it's worth doing - both for the consumer, and for GM's CAFE.

[milnersXcoupe]

Good points.

You've been selected to take the proposal to Lutz & the GM Board by the end of the Month: Sept. 30, 2008 .

Keep us appraised of your progress.

[Stovebolt]

Originally Posted by logansowner

With 7 or 8 gears, it's just going to shift all the time. 4 is not enough, but 8 is too many.

I wonder if Buick engineers in the 40's said the same thing...

"This newfangled 4-speed hydra-matic that the Caddy boys are talking about has too many gears. It'll be shifting all the time. We better go with three."

"Why not two?"

"Yeah, two's good..."

"How about just one?"

"Two's good, I said! MAKE IT SO!"

And so the Dynaflow was born.

[Blair1955]

Chaz_23

GM needs do get over their CAFE repression and learn how to build decent transmission from the Germans.

GM does better than decent transmissions some of the best automatic trans have come from GM / Hydra Matic. Over the years Hydra Matic has supplied to Rolls Royce, Volvo, Ferrari and Jaguar. I spent just over thirty years with now GMPT and feel we have great transmissions.

GM is still ramping up the 6 rwd and fwd and phasing out the 4 speed models. If 8 speeds are on the horizon they would be several years away. The cvt’s main problem is still the belt. They just don’t hold up in a large vehicle or a higher torque engine. Overall the cvt would be the way to go though.

[motorman]

small cubic engines will not be able to "pull" 8 speed transmission because they do not have enough power. my 2008 corvette turns about 1500/1600 RPMs when in top gear at highway speeds and no small engine will pull smoothly at this RPM

[milnersXcoupe]

If one is arriving in a final gear, 6th or 8th - and it is too steep for a 75 mph cruise - the gearing ratio spread was poorly selected by the Factory.

Placing a top gear good for 135 mph in any production car - Corvette or other - tells me someone's reading too much Road & Track magazine - again, not placing emphasis on gearing / transmission selection.

A blistering turbine smooth 0 - 75 mph time is where it's at - with final gear suited to the engine torque band = multi gearings.

As to GM releasing an 8 spd in a few years time - Gasoline is $4.00 a Gallon - right now.

Transmissions for Electric Hybrids - being 2 spd. units should be their focus - and in production - in a few years time.

Better to source and produce under agreement the ZF 8 for right now production than pursue development expenditures for an in_house transmission slated for years away production - and then slated for 'Prestige' only introduction.

'Prestige' marketing ended with Global Economy Marketing and the Internet.

And - I'm not the only consumer who won't buy a car with a 4spd trans automatic - New or Used - .


If the push for using Natural Gas as a Heavy Transportation Fuel - and it's by product LPG is applied to private vehicles, piston engines will continue as primary power for an extended time period - bridging the technology / production / sales gap to Electric / Hybrid / Fuel Cell vehicles - but not that long a time frame.