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GM to Introduce Saturn Vue Green Line 2 Mode Hybrid at Detroit Show; Production Begins This Year

Chassis and powertrain of the Vue Green Line 2 Mode hybrid. Click to enlarge.

GM will unveil the 2009 Saturn Vue Green Line 2 Mode, the first front-wheel-drive compact SUV powered by GM’s two-mode hybrid technology at the North American International Auto Show, running in Detroit from 13-27 January.

GM anticipates the Vue Green Line 2 Mode will deliver an estimated 50% fuel economy increase over the non-hybrid V-6 Vue. It also is expected to have a driving range of more than 500 miles (800 km). Production is slated to begin in late 2008.

The Vue Green Line 2 Mode will qualify as a Partial Zero Emissions Vehicle (PZEV) in the state of California and other states that have adopted California’s motor vehicle emissions rules.

The Vue Green Line 2 Mode is GM’s first application of two-mode technology on a front-wheel-drive vehicle. The two-mode system is currently on the V-8-equipped Chevrolet Tahoe 2 Mode and GMC Yukon 2 Mode full-size SUVs, and becomes available in 2008 on the Cadillac Escalade 2 Mode luxury SUV and Chevrolet Silverado 2 Mode full-size pickup.

The two-mode system consists of twin, active-cooled 55-kW electric motors integrated into the 2MT70 automatic transmission. Energy to power the motors comes from a 1.8 kWh, 300V nickel-metal hydride battery pack, which consists of 22 nickel-metal hydride modules and is packaged behind the second-row seat below the cargo floor.

The transmission is mated to GM’s 3.6L V-6 VVT with direct injection technology. In the first mode, at low speed and light load, the Vue Green Line 2 Mode operates in one of three ways depending on conditions and battery charge level: all-electric power, internal combustion engine power or a combination of the two. All reverse operation is driven by the electric motors.

The second mode is used primarily at highway speeds to optimize fuel economy. It provides electric assist in addition to six-cylinder power when conditions demand it, such as trailer towing and climbing steep grades, and to allow the engine to run at its most efficient point under less-demanding conditions.

No engine speed changes are necessary for the mode shift to occur. The result is exceptionally smooth, seamless acceleration and responsiveness. At all times, the system’s Hybrid Optimizing System (HOS) collects torque-based data, deciphers it, then determines the most fuel-efficient means of propelling the Vue Green Line 2 Mode.

The Vue Green Line 2 Mode’s standard engine is an advanced 3.6L V-6 VVT with direct injection, a member of GM’s family of high-feature V-6s. The direct injection engine uses regular unleaded fuel.

Direct injection delivers fuel directly to the combustion chambers and permits a higher compression ratio (11.3:1), improving fuel efficiency. Additionally, the technology reduces cold-start hydrocarbon emissions by up to 25%.

The 3.6L VVT with direct injection also features a US auto industry-first isolated fuel injector that greatly reduces the ticking noise associated with other direct injection engines. Other noise-reduction features include the use of acoustic foam in the engine valley and cover.

Because the hybrid system changes the weight distribution on the Vue Green Line 2 Mode, special chassis refinements such as revised front and rear spring rates; revised front and rear stabilizer bar rates and recalibrated front struts and rear shock absorbers help ensure a smooth driving experience.

The Vue Green Line 2 Mode is equipped with a “fully blended” electro-hydraulic brake system that enables 100% regenerative braking (batteries are charged during braking), 100% friction braking (traditional four-wheel disc braking) or a combination of the two. During regenerative braking, the system converts kinetic energy to electrical power, then stores the power in the Energy Storage System.

A 12V rack-mounted Electric Power Steering system replaces a conventional column-mounted hydraulic system and saves fuel, gaining up to a half-mile per gallon of gasoline.

When it arrives in dealer showrooms in the fourth quarter of 2008, the Vue Green Line 2 Mode will be Saturn’s third hybrid, joining the Vue Green Line 4-cylinder hybrid SUV and the Aura Green Line sedan.

GM is also working on a plug-in version of the Green Line 2 Mode. GM has awarded advanced battery development contracts to the A123Systems-Cobasys partnership and Johnson Controls–Saft Advanced Power Solutions, LLC to design and test lithium-ion batteries for use in the PHEV version. (Earlier post.)



assuming its a 50L tank (11 gallons), 800 km works out to 16 km /L (6.25L/100km) or 37.6 mpgUS. Not bad for a vehicle that does 0-60 in 7 seconds, it can keep up with a honda civic SI without the guzzy status of the premium fuel.

Could easily eat the highlander hybrid alive if they offer 7 passenger seating with the VUE.


It could have an 11 gallon tank, but assuming it has the same ~16-19 gallon tank it's predecessors had it'll get ~25-30+mpg.


I think the 2007 Vue has a 16 gallon tank and an EPA fuel mileage rating of 23 city, 29 highway. Lets say it gets 24 MPG overall. Now if the Hybrid gets 50% better mileage, as the article suggests, then overall it would get 36 MPG. Now if the fuel tank remains at 16, and 2 gallons are reserved (14 gallons of driving range fuel) then the fuel tank driving range works out to 504 which is "greater than 500 miles." On the other hand, if we use highway mileage and drain the tank, we can calculate a driving range much "greater than 500 miles" closer to 700 miles.

Rafael Seidl

3.6L is still about a third more displacement than a passenger car really needs. GM could lop off a couple of cylinders and adding a turbo. Any lag could be masked by the electric motors.

Indeed, recent R&D by Mahle and others in Germany suggests that you can cut displacement in half and still maintain rated power if you apply sequential turbos. Moreover, dual-boosted engines do not suffer from perceptible turbo lag.


It's a 50% increase over the current six, so they're ~28-29mpg combined.


Could someone stop these jerks above trying to sell stuff on this website. Spamming low-lifes. This website is for discussion not to sell their car parts. Imagine if every car part place placed ads in the comment areas. This website would totally suck!


When is GM going to be releasing this two-mode hybrid in something that you can parallel parking without someone helping you? I don't want an SUV or "crossover." I want an Astra two-mode hybrid!


It seems odd that they decided to go with the V6. The Escape has an I4 and gets better mileage. I guess that they are going after the Highlander towing market.

Dave K.

The sad truth is G.M. is 10 years behind Toyota and they won't build a car that competes with the Prius or even the Camry Hybrid because it would really look sad.
Their only real hope is the Volt, something that T. doesn't build.


Has the Atkinson cycle used on the Escape (and first on the Prius) been dropped ?

Dave I just checked out Toyotas web sit and the 4 cylinder camera hybrid gets 33/34
if the new GM SUV gets 30 combined on a 6 cylinder more horse power and a heavier vehicle How is this ten years behind???

Mike Z.

Something does not make sense here: The BAS Equipped Vue is rated at 28 mpg combined (25/32), so you would have to figure that a 2-mode equipped model best that by a nice margin. In my book it needs to beat the Escape Hybrid or it's game over.

I think that GM though is setting themselves up for under promise and over deliver on this one, as they are not citing what bases is used for stating the improvements, and that the Tahoe hybrid has a smaller fuel capacity than the non-hybrid version.

From my understanding, GM is using it's largest displacement engines for use with hybrids so that they can benefit from displacement on demand, allowing the engine to run in a 3-cylinder mode more often. Not sure if you can do displacement on demand with a turbo.


Are you guys mixing the old and new EPA standards?


3.6L engine on an hybrid sedan non sense, pointless and futile marketing for an overweighted car that will nullify the benefit of the hybrid concept. One of the main benefit (among others) of hydrid concept is that it allows downsizing of the engine then reducing pumping losses, friction and weight, they totaly miss the point here. Anyway they will probably not sell a lot of these cars just as Ford dosen't sell a lot of Escape hybrid and Honda failed to sell the Accord hybrid that was returning 31MPG. I doubt that this one will do better. GM and Ford failed to understand the success of Toyota with the Prius as well as the unsuccess of Honda with the Civic and the Accord.


Yahoo autos has a lot of blogs about Escape owners having problems with their hybrids. There seems to be a lack of quality and trained technicians. I hope GM can learn from those mistakes. Since the Tahoe hybrid costs $50k and up, I would think those affluent drivers would expect better quality and service as well.


Does this do cylinder deactivation? I don't recall reading that before.

Either way, I agree with Raf, re:turbocharging

Mike Z.

Yes, it uses cylinder deactivation, hence their use of the largest engine they have.


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With all the commentary of whether the gas tank is big small, or medium, the forest is being overlooked for the moss on one tree.

It is significant that the dual mode hybrid has now appeared on a front wheel drive vehicle. That is the REAL significance of this announcement.

This drivetrain is used on the crossover SUVs that they share floorpans with sedans. This means those sedans will be getting this drivetrain in the future, as will other GM branded crosover SUV stablemates.

Furthermore it appears the dual mode has a new size although I am not certain of that fact. It may be entire dual mode unit has been downsized, as well as converted to front wheel drive. I thought the electric motors announced first, were 70 HP units for the Tahoe, where as these appear to be 55 HP. I wonder if the gears and the entire 2 mode transmission is downsized to handle less torque, perhaps making it a lighter unit?

Also the all aluminum 3.6 VVT DOHC engine, has a 3 cylinder on demand system, like the V8s do for four cylinders. This would be the first application on a V6. It is not clear whether the Atkinson cycle is employed, but I see no reason why the modern V6 could not have that feature via valve timing. If it's not there it won't be long in coming.

Another significant engineering advance is all-electric AC and power steering units. But note the various mixed voltage requirements.

The Electrification of Ground Transport is becoming more than mere hope and expectations. It is now coming to the auto showrooms. Albeit in small numbers, so far, with the flood building in the next few years.


Obviously they are trying to justify the V6 by emphasizing the towing capability. Since not many people own boats, I am sure this lame pitch will not work.



No plug, no sale, end of story.

Brian P

I'm not sure about that engine using cylinder de-activation. As far as I can tell, it's the GM "high-feature" V6, same one used in several other premium models. The article itself mentions nothing about cylinder de-activation. The mechanism used on the push-rod V8's to de-activate cylinders won't work on a DOHC engine (although that's not to say it can't be done by other means - just not *that* method).

Are they going to be selling this alongside the "regular" Green Line with the 4 cylinder engine?

I thought Honda's experience with hybrids showed that the people who buy them don't want the big engines. GM seems bent on flogging the biggest engines possible along with the hybrid technology ... Should have done the same thing, but with the Ecotec 4 cylinder ...

no mention of price premium???

Stan Peterson


I agree that the eventual large sedan or small crossover drive train will resemble the Mercedes F700, if hydrocarbon fuel or CO2 continue to be concerns. (But I doubt both assumptions).

On automotive technologies though, I think there are valid concerns about combining selective displacement via cylinder shedding, and turbo-charging.

The turbos will need variable vaning and extensive rapid charge gating to not over stress ICE components when in reduced cylinder operation. I am somewhat concerned with the response time of any turbo to match cylinder shedding and adding, that has become very fast under computer control. The sheer inertia of a column of compressed air, might make employing both together, unfeasible.

It is still in the very early stages of the conversion to Electrification of Ground Transport, but some trends seem to becoming evident. For small vehicles, Series hybrids seem like the Chevy Volt seems to be where manufacturers are going. For mid-size performance vehicles and larger vehicles, 2 mode hybrids with even more gearing may be the choice. I suspect that the Diesel and HCCI will be the eventual re-charging engines of choice.

FCEV don't make much economic sense, I think. Where they do appear, it will where the largest powers will be needed, and costs may not be a major consideration. Will FCEV rail locomotives be the logical entry point?

The HCCI for Series hybrids seems obvious to me, as such configurations allow maximum amounts of operation in the HCCI band and I think HCCI engines can be lighter than diesels. All will go PHEV for the sheer benefits in operating costs.

Over time this may shift as the gating function appears to be battery cost and power. That will improve over time, and shift the choice for series hybrid PHEVS up the size scale, I suspect. Trucks will stay diesel or diesel 2 mode hybrid. That is the easiest way to provide the requisite torque and fuel efficiency.

BEVs will enter at the smallest vehicle end, and migrate similarly up in vehicle size as battery technology and manufacturing costs decline, but I think their acceptance will always be limited until distances per charge get very large. That will take a chemistry more advanced than LiIon.

Once the singular choice of liquid hydrocarbons is bypassed by electrification, than there are many substitutes available that can motivate electrons. They will end with controlled Fusion in the not so distant future. But even the worst, are cleaner than a "clean" ICEs as well as being more efficient.

Efficiency is a big consideration and low energy content sources like solar or wind need prodigious capital investment and inputs to create not much power.

What do you think?


One part of this article that catches my eye is the segment on regen braking. Here's a little more detail on this feature from the ABG article:

Regenerative braking can come in at any speed, and any combination from 100 percent regen to 100 percent friction braking is possible. The percentage of regen depends on the amount of deceleration requested by the driver's brake application and the state of charge of the battery. Under most normal braking situations, the majority of which are less than 0.3g of decel almost all the braking will come from regen. Deceleration beyond about .35g, or when the battery is fully charged will add in friction braking. The regen limit is in part due to the rate at which the battery can absorb energy. In addition to regen blending, the brake system also provides full anti-lock braking, traction control and electronic stability control.

My questions for GM are:

1) Is this a "brake-by-wire" system? Or is there still some sort of mechanical connection extending from my foot to the brakes and wheels? I like having a rugged mechanical backup no matter what (although I guess the parking brake counts).

2) Is this regen and traction control software going to find its way into future vehicles like the Volt?

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