2006 NAIAS: Chevrolet Tahoe Two-Mode Full Hybrid

[Northstar]

For release: Jan 8, 2006 at 12:01 AM EST

CHEVROLET TAHOE WITH TWO-MODE FULL HYBRID EXPLOITS FUEL SAVINGS, SUV DRIVING PLEASURE AND PERFORMANCE

DETROIT – The Chevrolet Tahoe full-size SUV has earned its outstanding reputation with independent consumer studies recognizing its sales and quality leadership. With the addition of the world’s first two-mode full hybrid propulsion system, the Chevrolet Tahoe takes its outstanding reputation even further with a 25-percent improvement in fuel economy and a superior driving experience that SUV customers know and love.

“The Chevrolet Tahoe Two-mode Hybrid combines the functionality and comfort of a full-size SUV with a two-mode full hybrid system that optimizes fuel efficiency in both city and highway driving, the way most Americans use their vehicles,” said Tom Stephens, group vice president, GM Powertrain. “The Tahoe Two-mode Hybrid delivers on GM’s commitment to apply advanced technologies where we will realize the most fuel savings.”

The Vortec V-8 powered Tahoe Two-mode Hybrid is expected to deliver a composite fuel efficiency improvement of 25 percent when combined with Active Fuel Management™ cylinder deactivation technology. The Tahoe Hybrid will go on sale next year as a 2008 model, along with the GMC Yukon Two-mode Hybrid. Pricing and production volumes have not been announced.

Design Manager David Smith and his team gave Chevy Tahoe Two-mode Hybrid a distinctive look befitting its unique powertrain, while ensuring a design reflecting that it is still unmistakably a Chevy. The Tahoe Two-mode Hybrid is 10 mm lower in the front and touts additional aerodynamic features compared to the non-hybrid Tahoe. Special features, including prominent hybrid badges and a Glacier Gold exterior finish, complete the look.

“We took the brand-new, next-generation full-size truck platform, which already had segment-leading fuel economy and world-class aerodynamics, and took it to the next level,” said Mark Cieslak, assistant vehicle chief engineer for the Chevy Tahoe Two-mode Hybrid. “This was in addition to maintaining important performance attributes of full-size trucks, such as off-road capability, towing at 6,000 pounds, great 0-60 times and much more. It was understood from the start that we would deliver the goods on fuel economy, with typical full-size truck performance, and provide the integration detail that results in a flawless vehicle. And we have, with confidence.”

GM, BMW and DaimlerChrysler are co-developing the two-mode full hybrid system that will leverage automatic transmission technology and electronic controls in an integrated, powerful and compact system that can be used with both gas and diesel engines.

The Tahoe, the industry’s best-selling SUV, was completely redesigned for 2007 with dramatically increased attention to detail on nearly every aspect of the vehicle. The development team focused on improving ride and handling, quietness, efficiency, and safety and security. They refined the interior and gave it a distinctive, sporty exterior.

“Tahoe is known for delivering what its customers want, whenever they want to do it,” said Ed Peper, Chevrolet general manager. “The Tahoe Two-mode Hybrid offers great performance, 25-percent better fuel economy and all of the kind of utility that our current SUV has.”

The two-mode hybrid system

GM’s two-mode full hybrid system in transit buses has been established as the starting point for the GM-BMW-DaimlerChrysler collaboration. The design integrates proven automatic transmission technology with a patented hybrid-electric drive system to deliver the world’s first two-mode full hybrid.

The two-mode is patented hybrid technology with two modes optimized for city and highway driving. In the first mode, at low speed and light loads, the vehicle can operate in three ways: electric power only, engine power only or in any combination of engine and electric power. When operating with electric power only, it provides all the fuel savings benefits of a full hybrid system. Leaving the engine shut off for extended periods of time and moving under electric power at low speed is key to reducing fuel consumption in heavy stop and go traffic.

The second mode is used primarily at highway speeds. In addition to electric assist, the second mode provides full eight-cylinder engine power when conditions demand it, such as when passing, pulling a trailer or climbing a steep grade.

The second mode integrates sophisticated electronic controls, such as Active Fuel Management, cam phasing, and late-intake valve closure, allowing even more efficient engine operation.

Two-mode system innovations allow for more compact packaging because its compact and powerful electric motors are designed to fit within the approximate space of a conventional automatic transmission – an efficiency advantage compared with today’s typical single-mode systems that rely on much larger electric motors.

A sophisticated controller determines when the vehicle should operate in either mode of the two-mode drive system. Input from the controller determines the necessary torque for the driving conditions and sends a corresponding command to the engine and electric motors. The engine and electric motors transfer torque to a series of gears in the transmission, which multiply torque similar to a conventional automatic transmission to propel the vehicle. But unlike conventional continuously variable transmissions, the two-mode full hybrid’s electrically controlled system uses no mechanical belts or bands. Shifts between the two modes are synchronous, which means no engine speed changes are necessary for the mode shift to occur, resulting in ultra smooth accelerations.

The 300-volt battery pack provides electric power for the system, and while it is larger than a typical automotive battery, it is designed to fit in the vehicle without compromising passenger space. Special converters located under the vehicle’s hood convert the motors’ AC output to DC current and power conventional 12-volt accessories, such as interior lighting, climate control and the radio. The vehicle’s internal combustion engine provides power to charge the battery pack, so the vehicle doesn’t have to be plugged in to keep the battery pack maintained.

Because the architecture can be scaled to fit multiple vehicles and adapted to gasoline or diesel engines, the two-mode full hybrid can be applied globally. In Europe , for example, where diesel engines are common in passenger vehicles, it can provide a significant reduction in fuel consumption, which would help automakers meet the region’s ever-stringent carbon dioxide emissions standard.

“We have several additional proprietary innovations that will make the two-mode system even more capable in high power-to-weight ratio vehicles, such as in SUVs and full-size pickups … innovations that combine our two-mode full hybrid with our extensive capability in automatic transmissions and electronic control systems,” said Stephens. “We believe it is the most efficient full hybrid design for a broad variety of vehicle configurations.”

Designed for efficiency

When it comes to saving fuel, even the most discreet design features can add up to significant fuel savings. Design Manager David Smith’s team used the existing, newly redesigned Chevrolet Tahoe, which already features segment-leading fuel economy and world-class aerodynamics, as a basis for additional aerodynamic refinements aimed at achieving even further fuel savings. Testing was conducted in GM’s aerodynamics laboratory in Warren , Mich.

The front of the Chevrolet Tahoe Two-mode Hybrid has been lowered 10 mm compared to the conventional Tahoe, which provides additional aerodynamic benefits as well as a smoother and sleeker appearance. The hood and liftgate are made of aluminum to trim weight, and the leading edges of the hood have been streamlined.

The Tahoe Two-mode Hybrid retains Chevy’s trademark dual-port grille with Chevy bowtie, but with a larger intake to accommodate the hybrid powertrain’s higher airflow requirement for cooling. The fascias are tuned at the corners and air dam, and the running boards are flared in front in an effort to guide airflow around the wheel openings.

“This truly looks like a special vehicle,” said Smith. “It is packed with details, and every one of them serves a function.”

There’s no mistaking this truck for anything other than a hybrid: Badging appears on the C-pillar, on the rear liftgate and on the hitch cover.

Other aerodynamic refinements include sharpening of the D-pillar rearward, including the taillamps, a CHMSL appliqué detail spoiler over the rear hatch and a closeout panel under the back of the vehicle to facilitate airflow.

Lightweight, aero-efficient wheels with the lowest rolling-resistance tires available for full-size trucks further trim fuel use, and are complemented with a tuned ride to provide the ride and handling performance and attention to detail that customers expect from a totally integrated vehicle.

Chevrolet Tahoe Two-Mode Full Hybrid from MPH-Online

[Derek77]

Thank You GM! Bob mostly.

The could easily use the same parts that are on the Hybrid version on the regular production Tahoes and lower the weight, increase aerodynamics, which all improves mileage.

[Croc]

OK I love what I'm seeing here in CGI...now gimme the real thing!

[Cadillacfan]

Not bad. I like how they give it a style tweaking to differentiate it from the regular Tahoe. I also find the lack of tow hooks in the front amusing.

[pow]

Technology seems solid... have to read more into it... I'm not sure about the looks or the concept, now that the chin is so low. I have a feeling the upcoming Acadia can achieve the Tahoe's utility and get similar MPG just by weighing less.

Edited January 8, 2006 by empowah

[jbartley]

that's fantastic, GM put effort into this! buyers will be fighting eachother for full size SUV's that get 20/26.

the market is perfect. the avg mom that wants an SUV doesn't need to go off-road and stuff, but does want the size and fuel eff.

..and now they have it! amazing.

GM will sell every single one!!

[pow]

that's fantastic, GM put effort into this! buyers will be fighting eachother for full size SUV's that get 20/26.

the market is perfect. the avg mom that wants an SUV doesn't need to go off-road and stuff, but does want the size and fuel eff.

..and now they have it! amazing.

GM will sell every single one!!

Thing is... there's this particular minivan that gets even better mileage, fits just as many people more comfortably, accelerates just as quickly, probably handles better, and is a lot cheaper. Now I realize the Tahoe is a lot cooler, can tow more, and maybe go off-road, but IDK. The hybrid system will be more logical in a Silverado or crossover, or even a Tahoe without the body modifications. The changes seem to detract from its appeal of being strong, elegant, and so on.

Edited January 8, 2006 by empowah

[Guest Josh]

People want to buy American.

[Ghost Dog]

Hmm Trying hard to fight off a wisecrack about the Rationality.

[chevynj]

Can't wait for GM to sell these and show that they can make a good hybrid too. They just have to avoid all of the first year bugs and prove that this new system is as good as Toyota's which i believe is going into variation 3 or 4. But this looks excellent. Hopefully this hybrid will really deliver!

[AAS]

Thing is... there's this particular minivan that gets even better mileage, fits just as many people more comfortably, accelerates just as quickly, probably handles better, and is a lot cheaper. Now I realize the Tahoe is a lot cooler, can tow more, and maybe go off-road, but IDK. The hybrid system will be more logical in a Silverado or crossover, or even a Tahoe without the body modifications. The changes seem to detract from its appeal of being strong, elegant, and so on.

True, but do you see everyone driving that mini-van instead of the current Tahoe? So why wouldn't they be driving the next gen., hybrid Tahoe?

[Imaj]

GM is genius for giving the hybrid a different treatment, cuz part of what sells hybrids is the image

[mustang84]

I'm genuinely impressed by some of the new products I'm seeing come out of GM and Ford. I really like how they're avoiding the quirky looks that normally ensue with hybrids (Civic's moon-rover hubcaps/rims, Prius's egg shape). They are giving me a lot of hope for 2006. 25% better gas mileage sounds great!

[sciguy_0504]

I think it looks like a stripper Tahoe, probably because it doesn't have the roof rack. I'm not really into that.

The idea/powertrain is what I am into. Congrats, GM! Welcome to the major league. The setup sounds good, though I doubt a 3-ton + SUV is going to run on electric power only for any period of time, and I think people will be falling head over heels for it.

Just hope it meets the EPA estimates mileage numbers. :AH-HA_wink:

[Cory Wolfe]

Interesting... sounds awesome and love how it's different.

[Cadillacfan]

I think it looks like a stripper Tahoe, probably because it doesn't have the roof rack.  I'm not really into that.

The idea/powertrain is what I am into.  Congrats, GM!  Welcome to the major league.  The setup sounds good, though I doubt a 3-ton + SUV is going to run on electric power only for any period of time, and I think people will be falling head over heels for it.

Just hope it meets the EPA estimates mileage numbers.  :AH-HA_wink:

I think the reason for that is to improve aerodynamics. Another reason why they took off the side plastic.

[Clownzilla]

I'm genuinely impressed by some of the new products I'm seeing come out of GM and Ford.  I really like how they're avoiding the quirky looks that normally ensue with hybrids (Civic's moon-rover hubcaps/rims, Prius's egg shape).  They are giving me a lot of hope for 2006.  25% better gas mileage sounds great!

Also remember that it's 25% above an already improved engine! Great job GM!!!!

[FUTURE_OF_GM]

I think it's awesome.... Looks and all.

Of course, I'm a fan of lowered vehicles. And I like how the new grille picks up the influence of the SEMA vehicles of this past year.

Overall, a compelling effort! I think it'll do well!

[91z4me]

Looks like an SS stance, just needs a new bumper and chin spoiler. Also 25% of 20 mpg is 5mpg. So realistically this could get 25+ mpg on the highway!

[Ultra Magnus]

As much as I like it, I hope its not too little too late. I think if they would have these things out by march, people would really take notice. Its a great effort, dont get me wrong, but the pricing and availability needs to be there now not later.

[w00t_man]

Someone said that the Tahoe Hybrid has been removed from the show floor. Anyone know any details about this?

[john1701a]

Help me verify the accuracy of this illustration...

THIS WEBPAGE ...provides a larger version on a downloadable document.

I'm also searching for any technical detail you may have available. I don't want to misrepresent this "full" hybrid design. So whatever feedback you can provide would be greatly appreciated.

JOHN

http://john1701a.com

[siegen]

That's the last thing we need, more SUVs! Damnit, get these things off the road! I can't see around them in my lowered import!!!!

20/25 isn't good enough, even if it does manage to achieve those numbers (I don't think you'll see 25mpg on the freeway, too much wind resistance and weight). The Odyssey gets 20/28 right now with a gasoline only engine, better handling, safety features, equal room, and a better resale value! Oh crap, you can't put 24 inch dubz on the Odyssey though, I guess you got me there! (/sarcasm) Who's going to be towing a boat with a hybrid SUV anyways? People that own boats don't have money to spend on anything other than their boat (it's true), specially not the premium price of a hybrid vehicle.

FLAME ON!

[pow]

Heh, I don't know why, but the upcoming Escalade Hybrid just seems more appropriate than this Tahoe Hybrid.

[Cadillacfan]

That's the last thing we need, more SUVs! Damnit, get these things off the road! I can't see around them in my lowered import!!!!   

20/25 isn't good enough, even if it does manage to achieve those numbers (I don't think you'll see 25mpg on the freeway, too much wind resistance and weight). The Odyssey gets 20/28 right now with a gasoline only engine, better handling, safety features, equal room, and a better resale value!    Oh crap, you can't put 24 inch dubz on the Odyssey though, I guess you got me there! (/sarcasm) Who's going to be towing a boat with a hybrid SUV anyways? People that own boats don't have money to spend on anything other than their boat (it's true), specially not the premium price of a hybrid vehicle.

FLAME ON!

People should be free to drive what they want. If the government starts forcing us to drive compact cars because environmentalist groups don't like them.. then why don't we just let them make all of our decisions for us.

You're entitled to your opinion.. but people in the US and Canada are free to drive whatever the hell they want.. even if you don't like it.

Beauty of democracy.

Back on topic... GM should keep pumping out hybrid SUVs.. and not just for the GMT900. Give the trailblazer a little boost in sales before it goes bye-bye in a few years. The Equinox would do well with the same hybrid system the VUE has. The Torrent.... well.. the Torrent can burn in hell!

If you can't tell.. I'm not a fan of the torrent. It's badge engineering at it's worst.. and before people ask... yes.. I have sat in it and driven it.. and it's exactly the same as the Equinox in the flesh with the exception of the red gauges.

Edited January 20, 2006 by Cadillacfan

[pow]

If you can't tell.. I'm not a fan of the torrent.  It's badge engineering at it's worst.. and before people ask... yes.. I have sat in it and driven it.. and it's exactly the same as the Equinox in the flesh with the exception of the red gauges.

Still, Pontiac fixed all the complaints I had with the Equinox, notably the chintzy silver trim, the ugly HVAC knobs, the nasty steering wheel, the dreary grey interior (replaced with black), the blingy front grille, and the dated gauges. It's still flawed engineering-wise, but at least they got the aesthetics right.

[thegriffon]

Help me verify the accuracy of this illustration...

THIS WEBPAGE ...provides a larger version on a downloadable document.

I'm also searching for any technical detail you may have available.  I don't want to misrepresent this "full" hybrid design.  So whatever feedback you can provide would be greatly appreciated.

JOHN

http://john1701a.com

See this brochure from Allison Transmission for details.

http://www.allisontransmission.com/servlet...et=SA3592EN.pdf

More detailed information on its operation is available in filings with the patent office.

Edited January 20, 2006 by thegriffon

[BuddyP]

Someone said that the Tahoe Hybrid has been removed from the show floor.  Anyone know any details about this?

It was at the show on Monday the 16th

[ToniCipriani]

The windshield decal looks tacky though.

Otherwise very nice.