08' 2WD Chevy Tahoe Hybrid Review by LeftLanenews

[GMusa]

Review: 2008 Chevrolet Tahoe Hybrid two-wheel drive

Although most American buyers are largely abandoning the full-size SUV segment, there are still some that can’t do without the capabilities and size that a truck-based ‘ute offers. For those people, General Motors has created a greener alternative in the form of the Chevrolet Tahoe Hybrid.

What is it?

The same Tahoe Americans have loved for years, only with added fuel-economy and environmental benefits of a hybrid drivetrain. The two-mode Tahoe hybrid gives up little capability to its gasoline counterpart and is currently the only offering in the full-size hybrid SUV segment – save for its twin, the GMC Yukon Hybrid.

What’s it up against?

The competitors for the Tahoe Hybrid include the Dodge Durango Hybrid, Chrysler Aspen Hybrid, Ford Expedition and Toyota Sequoia. While the newest crop of large crossovers aren’t technically in the same segment as the Tahoe Hybrid, we’re sure buyers will likely cross shop the Tahoe Hybrid with the Ford Flex and even some of GM’s own Lambda-based crossovers.

Any big breakthroughs?

Although automakers have put hybrid powertrains in cars and smaller SUVs for years, the Chevrolet Tahoe Hybrid represents the first of its kind – a full-size hybrid. In addition to being the first full-size hybrid on the market, the Tahoe Hybrid is also the first vehicle to use GM’s two-mode hybrid system.

Co-developed with the former DaimlerChrysler and BMW, the two-mode hybrid system allows the Tahoe to travel on all-electric power at speeds up to about 30 mph and also combines the power of the electric motor and gas engine at highway speeds. Regenerative braking is also part of the two-mode package.

The result of the hybrid system is a vehicle that can tow up to 6,200 pounds and still win Green Car Journal’s “2008 Green Car of the Year” award.

How does it look?

From about 50 yards, like a typical Tahoe. But a closer look reveals GM doesn’t want anyone mistaking this hybrid for is gas-only stable mate. Our tester had no fewer than eight hybrid badges and decals adorning the Tahoe’s exterior. In addition to the hybrid badging, the Tahoe Hybrid also has a more aerodynamic front fascia than the standard model, as well as a unique wheel and tire package intended to increase efficiency.

While we’re sure the lower air dam helps eek out just a few more MPGs, it looks to be a little low to the ground for an SUV. We never had any issues with the front end, but the Tahoe Hybrid’s chin looks like it’s destine to meet with some parking ties.

And the inside?

Apart from a “Hybrid Power Flow Display” and a unique gauge set, the Tahoe Hybrid’s interior is pretty much identical to its gas-powered counterpart. Because of the vehicle’s overall size, the interior of the Tahoe Hybrid is extremely roomy – without any intrusion from the on-board battery pack — and we can see why the full-size SUV has become so popular with families over the last few years.

Second road seating has adequate room for three adults, but third row seating proved to be vexing in every way. Access to the third row takes a bit of athleticism and there is virtually no leg room to speak off – making it only bearable for short trips. The third row also impedes on the Tahoe Hybrid’s cargo space and does not fold into the floor. The only solution for more space is to physically remove the seats from the SUV which is easier said than done. The rear bench comes out in two sections, each weighing at least 60 pounds. Unless you have a family of seven or often sever as the neighborhood bus, it’s probably best to take the rear bench out and forget that it ever existed.

The overall fit and finish and look of the Tahoe Hybrid’s interior is good, but the quality of materials aren’t exact up to par for a vehicle costing $50,000. Hard plastics cover the Tahoe Hybrid’s dash and continue on the SUV’s center console and door panels.

The Tahoe Hybrid comes standard with an in-dash navigation system, which we grew quite fond of. Although the system does have a bit of a learning curve, it’s one of the easier ones in the business to operate. In addition to displaying navigation and radio functions, the touch-screen display also keeps you aware of what the hybrid system is doing at any given moment.

HVAC controls are just below the nav screen and are easy and straight forward to use.

The Tahoe Hybrid’s instrument display contains the normal things you would expects to find in a gauge cluster, but also has an ‘auto stop’ meter built into the tachometer and an ‘economy’ gauge. Although economy gauges are nothing new to the industry, we liked having one in plain view as it helped us to keep the hybrid system performing at maximum efficiency.

But does it go?

Don’t let all the hybrid badging fool you. At the heart of this beast is still a 6.0L V8, cranking out a combined 332horsepower and 367 lb-ft or torque. But mashing on the gas pedal of the Tahoe Hybrid gives you the same sensation as if there was a turbocharged powerplant underhood – the electric motor moves the Tahoe off the line at less than a blistering pace, but then the big V8 kicks in, providing enough power to get a bit of wheel spin.

The Tahoe Hybrid’s handling is pretty much par for the segment and is what you would expect from a vehicle tipping the scales at over 5,600 pounds. But despite that heft, the Tahoe Hybrid is extremely maneuverable at parking lot speeds, thanks to a well-boosted power steering system.

Why you would buy it

You’re already in the market for a top-of-the-line SUV but want a vehicle that will save you a little bit at the pump. With a starting price of $49,590, the Tahoe Hybrid commands a few thousand dollar premium over the standard Tahoe, but buyers will actually recoup the difference in gas savings in about five years.

Why you wouldn’t buy it

While driving the Tahoe Hybrid, we couldn’t help but liken it to a high definition VHS tape. Sure it progresses the segment, but is it even something we’ll be using in a few years? We averaged 21.7 mpg in the Tahoe Hybrid (although admittedly in mostly highway driving) – which is very good for the segment – but we could have probably seen just as high or better economy in a Buick Enclave or GMC Acadia.

If you don’t need the ability to tow 6,000 pounds, you’d probably be much happier in a large crossover. In addition to saving you tens of thousands at the dealer, you’ll probably match or beat the Tahoe Hybrid in fuel economy.

Photos at Link: http://www.leftlanenews.com/chevrole...id-review.html

[eurohazard]

See that works for me. I like the little full size Tahoe Hybrid. I think it's funny that they knock the hard plastics in the dash.....at least the dash looks nice. Almost 22 mpg? Hell my Armada might have gotten 17 mpg in that kind of driving.

I'd seriously consider one if:
- My Armada gets totaled
- GM or dealership discounts by $8,500.

I'd love to see:
- Integrated folding 3rd row (removing seats is lame)...but I understand the frame/rear suspension is a limiting factor
- More towing capacity, or real world reports of people towing 6k lbs in a Hybrid Tahoe
- real 6-speed AT

[Tomko]

Strange, but there's no mention of the six speed Hydra-Matic.

[eurohazard]

Originally Posted by Tomko

Strange, but there's no mention of the six speed Hydra-Matic.

Because it doesn't have one. It's a 4-speed AT.........but GM confused folks into thinking it was a 6-speed AT by including the gears for the electric motor, when all added up = 6.

But thanks for reminding me....I'll add it to my wish list!

[mobyss]

Originally Posted by eurohazard

Because it doesn't have one. It's a 4-speed AT.........but GM confused folks into thinking it was a 6-speed AT by including the gears for the electric motor, when all added up = 6.

But thanks for reminding me....I'll add it to my wish list!

Are you kidding about the transmission???

This is the highest-tech fullsize truck GM has ever built and they're not using the real 6-speed from the Escalade and Denali? Why the heck not?

Seems that they could get another 1 or 2 mpg out of it. Oh well - I guess I should have figured they'd find a way to skimp.

I do wish they'd offer this hybrid powertrain in the "base" model - with cloth seats, manual AC, no nav system. It would be nice to get this vehicle for $35k.

By the way - I've noticed that Cadillac in your posts - why did you get the small engine, and not the full-size 500 ci? ;-)

[roteague]

Originally Posted by mobyss

Are you kidding about the transmission???

This is the highest-tech fullsize truck GM has ever built and they're not using the real 6-speed from the Escalade and Denali? Why the heck not?

Who says it isn't. Go back and some searches on the forum, rather than jumping to conclusions.

The system uses an electrically variable transmission with two hybrid modes of operation that optimize power and torque for various driving conditions.

[rob2299usa]

wow except for roteague, you guys really need to do your research... the gm two mode hyrbids may have 4 fixed gear ratios but combined with the electric motors this creates an evt (electrically variable transmission). This basically allows it to have an infinite number of gear ratios between two fixed points.

"EVT's are capable of continuously modulating output/input speed ratios like mechanical CVT's, but offer the distinct difference and benefit of being able to also apportion power from two different sources to one output." -Wikipedia

There is a whole section under transmissions at wikipedia about evt's... check it out

http://en.wikipedia.org/wiki/Transmission_(mechanics)

[eurohazard]

Originally Posted by mobyss

By the way - I've noticed that Cadillac in your posts - why did you get the small engine, and not the full-size 500 ci? ;-)

hehe...in case it was a serious question; only the FWD Eldorado had the 500 ci (same engine just a crankshaft w/ more stroke). Later year Caddy's had the 500 ci, but lower compression and hp/torque!

Originally Posted by roteague

Who says it isn't. Go back and some searches on the forum, rather than jumping to conclusions.

The system uses an electrically variable transmission with two hybrid modes of operation that optimize power and torque for various driving conditions.

I think you're the one jumping to conclusions. mobyss was only asking because of the statement I made. But I happen to be more right. There are 4 fixed forward gears. The continuously variable transmission is for the electric motors.
2008 CHEVROLET TAHOE SPECIFICATIONS

Drivetrain Front- or four-wheel drive, gasoline-electric hybrid
Base Engine 6.0-liter V-8, gasoline-electric hybrid
Emissions EPA/CARB Tier 2, Bin 5/LEV
Valves 16
Valve Configuration OHV, variable valve timing
Horsepower @ rpm 332 @ 5100
Torque, lbs-ft @ rpm 367 @ 4100
Transmission Two-mode continuously variable hybrid transmission, 4 fixed gears
Fuel Economy City/Hwy, mpg 21/22 (2WD), 20/20 (4WD)
Cruising Range, mi 525
Cargo Volume, cu ft 60.3 (with second and third row seats folded)
Fuel Capacity, gal 24.5
Towing Capacity, lbs 6200
Curb Weight, lbs 5617
Wheelbase, in 116.0
Length, in 202.0
Width, in 79.0
Height, in 76.9
Base MSRP $55,000 (est.)

This is a straight cut and paster from GM's press literature.

Here's some more from wheels.ca.com: http://www.wheels.ca/Hybrid/article/47557
"Instead of the common hybrid use of a continuously variable transmission, GM uses what it calls a "2-Mode continuous electric ratio hybrid transmission" that has four fixed gears."

Car and Driver says:
"The transmission resembles a conventional four-speed automatic to which two 80-hp electric motors are integrated by marrying them to the transmission’s three planetary gearsets. Despite the two-mode name, the transmission, which fits into the same space as the automatic in conventional Tahoes, seems to operate in three distinct modes."

Originally Posted by rob2299usa

wow except for roteague, you guys really need to do your research... the gm two mode hyrbids may have 4 fixed gear ratios but combined with the electric motors this creates an evt (electrically variable transmission). This basically allows it to have an infinite number of gear ratios between two fixed points.

"EVT's are capable of continuously modulating output/input speed ratios like mechanical CVT's, but offer the distinct difference and benefit of being able to also apportion power from two different sources to one output." -Wikipedia

There is a whole section under transmissions at wikipedia about evt's... check it out

http://en.wikipedia.org/wiki/Transmission_(mechanics)

Boy this is fun....everyone is challenging me today it seems. Ok rob......I read http://en.wikipedia.org/wiki/Transmi...28mechanics%29, did you...or did you only cut and paste the last sentence? Just because the "transmission" of the electrics motors is EVT, doesn't make the "real" transmission to the vehicle a CVT. Hell you want a good reference for the 4-speed AT GM uses on its 2-mode Hybrid....check out: http://www.gm.com/shop/vehicle.jsp?y...1650&pvc=11651, click "view details at Chevrolet.com", click "standard and optional", then click "specifications", then click "transmissions". In black and white are 4 ratios! First gear = 3.69, Second gear = 1.70, Third gear = 1.00, Fourth gear = 0.73. And reverse isn't mentioned.....which makes sense because I read somewhere that the electric motors (and those crafty EVT transmissions) power the vehicle in reverse.

[rob2299usa]

It would make a lot of sense for me to read it before just blindly posting something, so yes I did read it... but I really didn't have to since I actually KNOW how the thing works. You'll notice in my last post that I agreed to it having 4 fixed gear ratios.

To understand how it works you must know how a planetary gearset works. Since it is very difficult to explain in typed words, I will let howstuffworks.com explain it. The example they use is a prius but the two mode works in a very similar fashion.

http://auto.howstuffworks.com/hybrid-car7.htm


When accelerating in a tahoe hybrid it performs very similarly to a traditional cvt (it hits about 4.5-5k rpms and just sits there as you continue to accelerate).

Originally Posted by eurohazard

Hell you want a good reference for the 4-speed AT GM uses on its 2-mode Hybrid....

I hope you don't actually think that the transmission in this thing is an off the shelf 4-speed that GM just had lying around.

[Squashman]

I have a 2WD Yukon hybrid. Over my first 2100 miles, I averaged 21.9 mpg. On the highway cruising at 60-65, I usually get 24-25 mpg. Truthfully, I don't care if it has 4 sp, 6 sp, or 21 speed like my bike. I just know my Yukon's mileage is as good as my wife's 4 door sedan with a 5 speed auto.

On a side note, the vehicle is unbelievably quiet.

[Quickening]

It has 4 fixed gears and then two CVT like gears is my understanding. Even if that isn't quite right, its a different transmission than the old school 4 speed or the new 6 speed they are putting in everything.

[HEVguy]

Just to chime in, from an educated perspective, rob2299usa is absolutely correct, and eurohazard is completely oversimplifying, at best. At worst, eurohazard, you really do have no idea what a 2-mode eCVT is, in order to have 6 'fixed mechanical' gears, it would need 3 modes, which isn't necessary! This IS GM's MOST ADVANCED TRANSMISSION out there. Not only that, but it is MORE ADVANCED THAN THE PRIUS' eCVT, since it overcomes the Prius' requirement for higher speed motors for highway driving speeds, AND the consequantial Prius' compromises necessary for highway speed operation.

As far as the article. It seems like a pretty good review, focusing in on the details for those needing this kind vehicle, but staying true to the current question the US society is asking... why does everyone else need a vehicle like this? I didn't realize the Tahoe 3rd row was still difficult to configure, that is too bad.

[eurohazard]

Originally Posted by HEVguy

Just to chime in, from an educated perspective, rob2299usa is absolutely correct, and eurohazard is completely oversimplifying, at best. At worst, eurohazard, you really do have no idea what a 2-mode eCVT is, in order to have 6 'fixed mechanical' gears, it would need 3 modes, which isn't necessary! This IS GM's MOST ADVANCED TRANSMISSION out there. Not only that, but it is MORE ADVANCED THAN THE PRIUS' eCVT, since it overcomes the Prius' requirement for higher speed motors for highway driving speeds, AND the consequantial Prius' compromises necessary for highway speed operation.

So break it down for me genius. I KNOW I am not the only one confused by how the transmission in a Tahoe Hybrid works. How does the power from the gas engine's flywheel go through the transmission? And do me a favor, there's no need to compare to the Prius (unless you want to)...I am not here to convince someone Toyota's way is better.

[rob2299usa]

Relax eurohazard... nobody is claiming to be a genius here. We just think you are misinformed and should not be going around making claims about technology that you clearly do not grasp completely. I think you should check out the link I posted in my last post. If you don't understand that, then there is very little that anyone can do to help you understand how it works. Remember this is very new technology for the masses and most will have trouble comprehending how it works. Let me know if you have any specific questions.

[eurohazard]

Originally Posted by rob2299usa

Relax eurohazard... nobody is claiming to be a genius here. We just think you are misinformed and should not be going around making claims about technology that you clearly do not grasp completely. I think you should check out the link I posted in my last post. If you don't understand that, then there is very little that anyone can do to help you understand how it works. Remember this is very new technology for the masses and most will have trouble comprehending how it works.

I tried clicking the link before, but swear something else came up....but it works now. It's a very good read.

Originally Posted by rob2299usa

Let me know if you have any specific questions.

1) Can you make any sense of this statement?..."Not only that, but it is MORE ADVANCED THAN THE PRIUS' eCVT, since it overcomes the Prius' requirement for higher speed motors for highway driving speeds, AND the consequantial Prius' compromises necessary for highway speed operation."

2) The article was good........but that's talking about an inferior (according to rob) product. How does GM's 4 gears play into how their system works?

p.s. If it appears I was spreading false information......and that's not my intent (you guys may or may not know that).