still so sad...

Maybe Toyota's waiting for GM to invest huge sums in development and production and THEN bring over a superior hybrid minivan.

 

<div class='quotetop'>QUOTE(hyo silver @ Oct 14 2007, 06:42 PM) [snapback]525641[/snapback]</div>

i agree. with the desperate u.s. companies.. if you were to feed them a so so mini van, they try to get big and bold and defend it.. it's a huge market. only bring something if it's leaps ahead of the competitions new release.. think of the prius.

if they were bring a minivan hybrid out now... chrysler/mercedes would release one too. there may be flaws in both. you have to rember how a minivan is designed. lots of weight at times. bouncy kids. you need plenty of cargo room too. not having those seats fold into the ground is a huge loss.

on the other hand.. if they were to start the rolling of that "ball" then competition would be awesome. potentially extremely profitable.

 

OK, guys. Can someone out there provide me with a ready translation for some of the engineering-speak in this article?

For instance. Here is a quote from the article: "But the Prius, Escape Hybrid and several Honda hybrids have drawbacks. They can't tow heavy loads. And sustained uphill driving will eventually discharge the batteries enough to turn off the electric motor assist, which reduces performance and boosts fuel consumption. Those are problems the Two-Mode system has been designed to solve."

What does this mean? I never expected to tow much with my Prius. Of course, I never expected to tow much with my VW, my early Honda Accord, or even my Maximas. If I had purchased an F-150, I'd have different expectations. What does any of this have to do with the HSD or hybrids in general? Can't a hybrid with a larger ICE and electric motors (and more batteries) do the job?

Here's another one: "GM's Nitz said the Two-Mode is alone among hybrid transmissions. It can tow heavy loads such as boats and horse trailers. And the way it shifts gears is different. When the transmission changes gears, the engine speed stays the same."

What's the "Two-Mode" transmission, anyway? And, isn't there something about the planetary gear in the HSD that allows the ICE to turn the same RPM. Can some of the differences be explained in lay terms?

A third one for you: "How the power is sent to the wheels, through a series of clutches and planetary gears, is another way the Two-Mode is better than existing hybrid transmissions, Nitz said. In a conventional hybrid transmission, power is sent to the wheels through one or two paths: electrically through the motors or mechanically through the internal combustion engine. The electric path is less efficient, said Nitz."

OK. I'm sure that Mr. Nitz is much smarter than am I. At least he probably knows what he is talking about when it comes to transmissions. Still, I don't see how a "series of clutches" is better than a planetary gear with computer control. Doesn't the fact that there are more mechanical connections create energy loss (through heat transfer). Is the "electric path" truly so much less efficient that the mechanical connections of the Two-Mode (whatevery they may be) outperform the HSD in terms of efficiency and economy?

A little help in translation would be greatly appreciated.

 

http://en.wikipedia.org/wiki/Hybrid_Synergy_Drive

 

<div class='quotetop'>QUOTE(a priori @ Oct 14 2007, 09:49 PM) [snapback]525669[/snapback]</div>

Basically, it is an automatic transmission with motors added.


<div class='quotetop'>QUOTE(a priori @ Oct 14 2007, 09:49 PM) [snapback]525669[/snapback]</div>

The ability to disconnect entirely should provide an efficiency advantage; however, the physical design doesn't scale down well. The added complexity pushes production cost beyond competitive levels for smaller vehicles... hence GM pursuing "assist" and "series" hybrid options for them instead.

 

<div class='quotetop'>QUOTE(V8Cobrakid @ Oct 14 2007, 10:27 PM) [snapback]525677[/snapback]</div>

OK. I felt a bit insulted (or at least underwhelmed) by the response of simply dropping in a link to a description of the HSD. No, I still don't understand it. If you do, then please try to apply some common language in your explanation.

Still, I am wondering about the answers to my questions.

Despite feeling a little spat-upon by your posting, I did follow the link. Though the site was a description of the HSD that I'd read before, it did offer a link to a Wiki posting about the Two-Mode transmission. For those interested, here is that link: http://en.wikipedia.org/wiki/Global_Hybrid_Cooperation

So, I found out a bit more about this "new" transmission, and I thank you for getting me to that point.

 

The article is full of "will" and "could." The author optimistically assumes that GM "will" do something that has not happened yet, and happily points out what such an accomplishment "could" mean for GM.

If "would"s and "but"s were beers and nuts we'd have a hell of a party.

But the party at GM is a race to see how fast they can suck the last drop of oil out of the ground and burn it in vehicles that are 5 times as big as they need to be for the uses they're put to. And then they serenade us with the promise that "some day" those five-times-too-big cars will burn 10% less fuel than they do today.

 

<div class='quotetop'>QUOTE(a priori @ Oct 14 2007, 09:49 PM) [snapback]525669[/snapback]</div>

A gal here...just a few random thoughts.

Most importantly, never having met the man, I wouldn't make *any* assumptions about Mr. Nitz and his sagacity.

(1) This is true, sort of. The traction battery in the Prius is like a (relatively small) gas tank for the electric motors...when it's empty, the gasoline engine not only has to propel the car, but recharge the battery. This does in fact slow down the car (but the fuel consumption clam is mostly bogus, since all the Prius' energy comes from gasoline anyway, no matter in what form it ends up). But it's a situation which doesn't happen nearly as often as Mr. Nitz would have us believe.

The downside of Nitz's claim is that GM's system basically has too much extra capability for most daily driving situations...poorer fuel economy, more mass. That's why it's always there 100%, no matter what. I don't NEED 100% nearly all the time, personally!

The idea is to have just enough for most situations, not more than enough capability for any possible thing you might face (unless you're a guy who has issues with masculinity...then you'll drive a monster truck, and your biggest worry will be attacking other countries to get our oil back).

That's why the Prius is so efficient; a good balance of attributes.

(2) The Prius is not rated for towing; as a fuel economy first vehicle it would make no sense to carry around all that extra mass and capability which is almost never used.

Nitz is saying that GM's technology will likely be applied to SUV's and trucks (catering to their core market)...this will also address corporate fuel economy concerns (the trucks will do better on the EPA cycle), not really provide that much real world improvement (some PC'ers will debate me on this one, I'm sure)...and marketing can sell the heck out of the word "hybrid!" What could be better?

(3) GM claims that the electric mode of the Prius, which is used to support the power coming from the ICE at higher speeds, isn't as efficient as it could be...or, more specifically, transitioning the vehicle to only using the gas engine at higher speeds is better. Without getting into the specifics of the individual systems, I don't think it's possible to make such a sweeping claim with any accuracy.

Also, remember that the system in the Prius is years old...GM's idea SHOULD perform better, given...like, a decade...to take apart the competition's cars and educate their own engineering staff.

One more thing: GM's system is designed to fit into a normal automatic transmission...why they'd stick to an existing form factor determined by the shapes of things which aren't even there any more is a mystery, except to say that they'll likely be retrofitting it to existing models, not clean sheet of paper ones like the Prius.

So no chance to address things like packaging and weight savings...and, apparently, no interest to, either. :-(

Without addressing the weight issue, it's impossible to achieve significant fuel economy gains.

A hybrid drivetrain is NOT enough.

---------

GM excels at dream cars and the creation of PR releases that say they will actually be produced any day now...but have been clearly and repeatedly short of know how for ---literally--- decades now.

Toyota's had four generations of hybrid, two sold successfully in the US, and one in particular that created a brand name and was even made into a Monopoly piece.

Meanwhile, back at GM, they've yet to have any significant sales or engineering successes with hybrids. Don't forget, they canned their earlier BAS "mild hybrid" system, after only a few thousand vehicles were sold to their unlucky owners. I'd park mine next to my Cadillac Seville V8-6-4...
[laughing heartily]

So, I'd say the burden is on GM to prove that what they're saying, is true. And do so in the marketplace. Until then, I'll keep getting 45mpg...and not feeling like I'm sacrificing anything in the process.

 

<div class='quotetop'>QUOTE(Pinto Girl @ Oct 16 2007, 09:11 PM) [snapback]526641[/snapback]</div>

Thanks, Pinto Girl. I appreciate the added info -- and opinion!

 

<div class='quotetop'>QUOTE(a priori @ Oct 14 2007, 10:49 PM) [snapback]525669[/snapback]</div>

It means the author deliberately left off our Hybrid Lexus SUV, the 400h because we have no problem towing plenty (as does the Hy hi). skew the facts to lead the reader your way.

 

<div class='quotetop'>QUOTE(Pinto Girl @ Oct 16 2007, 10:11 PM) [snapback]526641[/snapback]</div>

Bravo! Nicely stated! Oh and here's a pic of the game ... i think I'm gonna buy it lol

 

The Highlander tows about 3500 lbs versus 5000 for the Non-Hybrid Version. Not sure on the exact numbers for the 2-Mode Tahoe but I believe it is almost identical to the Non-Hybrid Version. A valid question is how often you are going to tow more than 3500lbs but thats for each person to decide.

 

<div class='quotetop'>QUOTE(jimmy_6767 @ Oct 17 2007, 04:51 PM) [snapback]527095[/snapback]</div>

6500 lbs versus 8000

<div class='quotetop'>QUOTE(jimmy_6767 @ Oct 17 2007, 04:51 PM) [snapback]527095[/snapback]</div>

Quite possibly... never.

 

A couple of horses, a horsefloat (trailer) and associated gear will quickly exceed that figure.
As for frequency, make it 2-3 times a week.
My wife still has to drive a Cherokee for that reason.
Would love a Kluger (RHD HyHi) but they're towing capacity is sort of marginal for the above,
I've only been able to find one on the market here, and my wife hates the name Kluger.

 

Can anyone put these two statements together and tell me if GMs right hand knows what its left hand is doing please: -
(from post 3)

and this about the Chev Volt CONcept Car (wikipedia)

I know the first statement is true which is why Toyota went to a lot of trouble to ensure the bulk of power from the ICE goes to the ground through the power split device to the drive gears rather than through the electrical system.

 

<div class='quotetop'>QUOTE(patsparks @ Oct 30 2007, 04:05 PM) [snapback]532626[/snapback]</div>

It's more complicated than that. 60% of the torque going to the PSD goes to the wheels, and 40% of the torque goes to MG1, which generates electricity, which can be sent to the battery or to MG2 to help drive the wheels.

Torque is the rotational version of force, and no power is delivered by applying force unless the thing being pushed on moves.

Thus, when the car is at rest and you step hard on the accelerator, the engine revs up, turning the associated part of the PSD (I think it's the planet carrier, but I always get that confused) but until the car gets moving, none of the torque applied to the wheels does any work, so ALL the power goes to MG1. As the car accelerates, progressively more of the power goes directly to the wheels, and less to MG1.

Therefore, at low speeds more power goes through the electrical path (engine to PSD to MG1 to MG2 to wheels) and at freeway speeds more power goes through the mechanical path (engine to PSD to MG2 and wheels).

This is an elegant solution to the fact that at low speeds the electrical path is more efficient, while at freeway speeds the mechanical path is more efficient.

On the other hand, a series hybrid lends itself better to be a PHEV, since the Prius MUST turn the engine above 42 mph, and lacks sufficient acceleration to keep up with traffic from a stop light unless it burns gas. A series hybrid will have a big enough electric motor (or four) to operate entirely on electric while the batteries hold out. The Prius will be the better choice if you drive very long distances a lot, since it will be more efficient while burning gas than a series hybrid that's burning gas. But the series hybrid will be the better choice if you mostly drive within its electric range and can avoid burning gas at all; while having the ability to burn gas when it's necessary to make a longer trip.

 

The series hybrid has a slight advantage when it comes to generating electricity with the ICE. The engine needs only one set output. So you can focus on making it as efficiently as possible at that output. Instead of worrying about efficiency over a range of outputs.