Saturn Vue 2-Mode

[jonathanrohr]

Im sure people are gonna jump on me for posting 'propoganda', but regardless, this is pretty cool news:

Front-Wheel-Drive, 2-Mode Hybrid System Debuts in 2008

Saturn Hybrid SUV Expected to Offer Up To 45-Percent Fuel Economy Improvement

LOS ANGELES (Nov. 29, 2006) – General Motors Corp. will expand the industry’s most diverse portfolio of hybrid technologies in 2008 with the debut of its front-wheel-drive, 2-mode hybrid system in the Saturn Vue Green Line SUV, the automaker announced at the Greater Los Angeles Auto Show.

By using this sophisticated hybrid technology, the Vue Green Line 2-mode Hybrid is expected to deliver up to a 45-percent improvement in combined city and highway fuel economy compared with the non-hybrid Vue, based on current federal test procedures.

“We are delivering on our promise to continue our steady rollout of additional hybrid applications, each offering different levels of affordability, fuel savings and performance,” said Tom Stephens, GM group vice president, GM Powertrain. “This will be the auto industry’s first front-wheel-drive vehicle to use a 2-mode hybrid system, which improves fuel economy while maintaining performance and capability.”

The Vue Green Line 2-mode Hybrid SUV will be powered by GM’s 3.6L V-6 gas engine, with direct injection and variable valve timing, a nickel-metal hydride battery pack and two active cooled permanent magnet motors.

The front-wheel-drive, 2-mode hybrid system optimizes city and highway fuel efficiency by integrating two electric continuously variable modes with four fixed mechanical gear ratios.
This design is similar to the 2-mode hybrid system for rear-wheel-drive applications, which will debut next year in the Chevrolet Tahoe and GMC Yukon full-size SUVs.

The 2-mode hybrid system improves fuel economy by the following operations:
Engine off at idle
Low speed electric-only propulsion
Electric boosting during brisk acceleration, climbing steep grades or towing
Cutting off fuel to the engine during vehicle deceleration
Regenerative braking
Engine speed and load control

“The 2-mode hybrid system has the flexibility to improve fuel efficiency across a range of vehicles,” Stephens said. “For example, in 2003, we introduced the 2-mode hybrid system for transit buses. In 2007, the Chevrolet Tahoe and GMC Yukon 2-mode full-size SUVs will debut, followed by the Vue Green Line 2-mode in 2008.”

By using two electric modes and four fixed gear ratios, the 2-mode hybrid system’s electric motors are smaller, compared with traditional “one-mode” hybrid systems, and impose no significant limitation on the size of the engine.

Consequently, the 2-mode hybrid system fits into the same space as a conventional automatic transmission, minimizing packaging, cost and weight issues. The result is exciting performance and outstanding fuel economy.


http://www.gm.com/company/gmability/adv_te...008-113006.html

[Tideland Prius]

Why have 4 fixed gear ratios when you can have an infinite number within a set range?

Anyway, should've posted this in "Prius & Hybrid News" since it is a news article.. sorta.

[jonathanrohr]

<div class='quotetop'>QUOTE(Tideland Prius @ Mar 20 2007, 01:15 AM) [snapback]408778[/snapback]</div>

Anyway, should've posted this in "Prius & Hybrid News" since it is a news article.. sorta.
[/b]

Maybe.. but since it was written by GM, I had to be careful.

[SomervillePrius]

I'm also a little surprised the use a 4 speed gear box. I'm not sure how they will be able to make the transition from battery to ICE smooth.

Still this for me is an interesting car, if they see real world numbers around 45%. While I don't like the VUE it's the size of car I need.... I would still prefer to see it with a 4 cylinder engine.

With 45% improvements will it be better then the new highlander?

/Robert

[Jonnycat26]

<div class='quotetop'>QUOTE(SomervillePrius @ Mar 20 2007, 12:08 PM) [snapback]408944[/snapback]</div>

I'm also a little surprised the use a 4 speed gear box. I'm not sure how they will be able to make the transition from battery to ICE smooth.
[/b]

Calling it a 4-speed is a bit of a stretch...

"Its six mechanical options for operation include input-split and compound-split continuously variable EVT ranges and four fixed gear ratios with parallel electric motor boosting and regenerative braking."
[/b]

It's essentially the same as calling the Prius a one speed...

[donee]

Hi All,

Using a 3.6 liter V6 and a 2 Mode Hybrid CVT makes this kinda a power Hybrid. Especially, as the Vue is somewhat smaller than the Highlander and Escape. The Highlander is a bit of a power Hybrid too.

I believe the 2 mode Hybrid is continuously variable, just like the Prius, in two speed reduction bands. The motors are the same size, and configured differently. Its not a bad system, and somebody pointed out that its similar to the GS-450H arrangement.

Its about time GM got serious about the future.

[dipper]

IFFFFFF it works properly, at least GM's design will save more gas... a la more complex.

Two mode tranny for better freeway efficiency. And further efficiency with cylinder deactivation. Top that Toyota.... its your next move. Oh, I forgot... Toyota does not even know how to do cylinder deactivation for all the hybrid expertise.

How come no one is complaining about Toyota not stepping up? I love my Prius and all, but Toyota should not be as "good" as their F1 racing image shows.

[jonathanrohr]

<div class='quotetop'>QUOTE(Tideland Prius @ Mar 20 2007, 01:15 AM) [snapback]408778[/snapback]</div>

Why have 4 fixed gear ratios when you can have an infinite number within a set range?
[/b]

I know someone else pointed this out already but its a CVT and a 4-Speed. I **THINK** the reasons for combining the two is because when you do lock into a set gear (one of the 4) it results in more efficent power delivery than in the CVT. I **THINK** that the CVT is thrown in the mix just to further smoothen out acceleration and the spaces between the 4 speeds.

BMW, last I heard, was planning on leasing this design from GM on their upcoming hybrids.


<div class='quotetop'>QUOTE(SomervillePrius @ Mar 20 2007, 12:08 PM) [snapback]408944[/snapback]</div>

Still this for me is an interesting car, if they see real world numbers around 45%. While I don't like the VUE it's the size of car I need.... I would still prefer to see it with a 4 cylinder engine.

With 45% improvements will it be better then the new highlander?

/Robert
[/b]

Well this will be coming out in the new 2008 Vue (http://autos.msn.com/research/vip/fu...=0&usage=image) so its hard to peg exact estimates (which in itself is an oxymoron). Buuut, if we base it off the 2007 I see two ways it could "improve by 45%":

If it improves 45% over the 2007 4cyl, you would get: 32/39
If it improves 45% over the 2007 6cyl, you would get: 29/41

These are rounded and for auto trannys, and are also on the old EPA system.

So if you think about it, they would both AVERAGE out to be the same MPG. You could make the argument that GM shoudlve still done it with the I4 to keep the cost down, but you have to remember that there is already the low-cost BAS Vue. Im thinking their approach is to have a bargain-half-hybrid and all-out-2mode-hybrid. But how will the differentiate the true hybrid from the BAS, will they both still be 'green line'?

Furthermore, I think with all the time and planning GM has put into this, as well as the fact that they have alot riding on it, they were careful to make the best decision. My guess is that the 4cyl wouldve only done marginally better. Correct me if im wrong, but if you take out the extra fuel used to idle 2 more cylinders (ICE turns off at idle) and then take out the extra fuel used under heavy acceleration (electric assist), then it makes little to no difference between the 4 or the 6. Additionally, I would be willing to bet that the 6 gets better highway economy because it is more powerful, and dosent have to work as hard to go 80MPH. Its also probably a big factor that the new 3.6l V6 is GM's brand-new pride and joy VVT wonderchild, where as the I4 Ecotec is due to be significantly upgraded in 09 or 10.

[SomervillePrius]

Cool! if the can get all the technology to work! Seem a little complex but if it gives the real world advantages they claim they might have a turn around on their hands....

ANy chance FORD will do anything green? Their hybrid system went very quiet after the superbowl add!

[john1701a]

<div class='quotetop'>QUOTE(dipper @ Mar 20 2007, 01:23 PM) [snapback]409051[/snapback]</div>

And further efficiency with cylinder deactivation. Top that Toyota.... its your next move. Oh, I forgot... Toyota does not even know how to do cylinder deactivation for all the hybrid expertise.

How come no one is complaining about Toyota not stepping up?[/b]

How come no one is complaining about GM not offering cylinder-deactivation for more vehicles? Being a hybrid is not necessary.

Of course, cylinder-deactivation is less of a gain than what fewer cylinders provide, especially if you simply just shut all of them off instead. In other words, lets compare real-world data to the additional cost for that feature.

JOHN