Bottom line: It is a CVT based on planetary gears like Toyota/Ford, but THREE of 'em which can lock up in combinations to give CVT flexibility at low speed/EV mode and then fixed gear ratios at high speed/load like a normal tranny.

This will give the trucks all the tow/haul capacity of today's versions along with the EV flexibilty and efficiency, without having to use massive electric motors.

Keeping my fingers crossed!

http://www.sae.org/automag/techbrief...1-114-6-20.pdf

Hopefully GM will actually *build* it! They have a lot of neat designs and concepts, but they don't exactly have a great track record of bringing their ideas to the showroom floor.

Drive by the Dundalk plant- they're already starting to realign for it!

Just noticed your location. The plant that's building most of the hybrid machine hardware is in your backyard!

I don't expect you to have a clear understanding of the vehicle development process. Suffice it to say that if this was childbirth, the Tahoe Hybrid is 5 cm dilated. The baby will definitely be born. And to shortcut the obvious joke, it WILL NOT be stillborn.

Peace,

Martin

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

Well, this is sure the time for it with $3.25 gasline. When will this move into the 1/2 ton pickups?
Toyota was making a lot of noise about a 1/2 ton Hybrid Tundra, but they have been pretty quiet about it lately. I think I read something about Toyota running into a problem?Anyone have any idea?
It would be a big boost for GM to beat Toyota with the 1st "full hybrid" big vehicle that could seriously tow etc. I know GM has a hybrid pickup, but it gives just a modest mpg improvement. The built in generator is probably its main selling point(and a good one). Thanks.Charlie

You never know... Toyota might be having trouble adapting HSD to a large pickup truck. HSD seems like a great solution for small to midsize cars and small SUVs, but maybe it isn't ideal for big trucks.

Quite a while ago I posted something on that. Wish I could remember what thread it was in. Bottom line is, Toyota realized that scaling up the IMA to a truck duty cycle would run into some serious physical limitations (the motors get to be too big to package in the transmission tunnel under the vehicle). The GM 2-Mode system was alsways intended to package in such an environment, so the gear designs were focused around achieving that.

Toyota will likely figure out how to design the motors small enough yet potent enough to package under the tunnel and still provide truck duty cycle, but it'll take them longer than it has taken GM.

Peace,

Martin

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

Ashen,
My memory is a bit vague, but I heard something like that. It was something to the effect that durability while retaining the capability to tow 7000 lbs was a "problem". At 1st glance, I really didn't understant that; if the vehicle is twice the size(like a 5500 lbs truck relative to a 2900 Prius), just make the components twice as strong,and twice as powerful. On reflection, twice as powerful would work, but since the HSD has to be able to pull 13000 lbs of vehicle and trailer it will have to be a bit more than 4X as strong.The gear teeth will have to have 4X the surface area(and strength). This could mean the HSD it would have to be 4X as long or some combination of increased diameter and length..I don't know what the HH is rated to tow-does anyone know if it is the 3500 lb of the normal HH?.
I suspect it is something other than just putting in bigger gears and bigger motors. I wonder if the offroad pounding that a truck might get has something to do with the problem.
I also a bit puzzled on why the HH doesn't get better FE relative to its non hybrid competition.In Real World city driving the Prius gets 70% better FE than the Corolla or Civic 4 cyl autos. The HH however gets just 33% better FE than the Highlander V6 and maybe just 10-20% better than the Highlander 4 cyl.
Is there some problem in scaling up the Toyota hybrid system that "hurts" FE??
The Camry seems to scale up OK, but I haven't seen CRs 2007 numbers for the CH VS 4 cyl Camry.(I HAVE NOW AND THEY ARE EXACTLY WHAT(28mpg) THEY SHOULD BE RELATIVE TO WT AND CR's 35 mpg Prius mpg.(It beats the HCH2 in city mpg)
Usually in city driving there is a direct relationship between wt and FE-all other things being equal(which they aren't). A V8 Tundra weighs about 5000 lbs and it gets about 13 mpg city.A 2800 Corolla will get about23- 24- mpg city.These numbers are exactly what you would expect if FE (city) is directly pro to wt.
A HH should get and honest 30 mpg city if a Prius gets and honest 45mpg city.
Well,I'm not meaning to take shots at the HH, I'm just thinking out loud. It would certainly be nice to have a 5000 lb pickup that got an honest 24 mpg city.This seems unlikely since the HHs get about that(when driven carefully) and they are lighter,shorter,narrower,smaller tired etc.Thanks.Charlie

Ummm Toyota is HSD not IMA. The way I remember it is that HSD (Toyota) does scale up well but IMA (Honda) does not. The FEH and HH already use HSD so I don't think scaling HSD is a problem. Of course my memory is subject to error so if someone could confirm........

What is with the 'flywheel' end? The cut-away shows what looks almost like a small torque converter. Is that a liquid filled or operated clutch?

Is there a more detailed description around?

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
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