Taking the full-sized SUV hybrids to the streets

Not all big SUVs have to get bad gas mileage, according to General Motors. I guess it depends on what you consider bad.

The General is rolling out its latest hybrid system--its first full hybrids--on full-sized three-ton SUVs this fall. The automaker estimates the new Chevrolet Tahoe and GMC Yukon "Two-Mode" hybrid SUVs will get about 20 mpg, city or highway. Indeed, driving around New York city last month, making no attempt at maximizing fuel economy, the trip computer showed 19 mpg. Feathering the gas to maximize driving on the batteries brought that up to an indicated 24 mpg. Our sophisticated fuel economy testing has shown differences between real-world MPG and what trip computers project. Basically, we'll believe it when we see it (or, in this case, test it).

That's not bad for a full-sized SUV, but it's worse than any hybrid we've tested before. When you consider the performance, 20 mpg starts sounding better, though. These are the first hybrids with full-sized towing ability (6,800 pounds--a little less than a typical Tahoe's 7,200-pounds). And GM says they can accelerate from 0-60 in about 8 seconds.

All this is accomplished by GM's new full-hybrid system that uses two electric motors inside the transmission to allow the trucks to shut off and restart the gas engine at stoplights, accelerate from a stop silently on electric power, recharge the batteries while braking, and use the electric power to assist the engine at higher speeds. Like most hybrids, the CVT (continuously-variable transmission) has an infinite range of gear ratios. For heavy-duty work the transmission shifts into a traditional direct drive mode with four stepped gears just like a traditional four-speed automatic. The hybrid system adds 400 pounds to the Tahoe's curb weight. Partially offset by other weight savings, that pushes the Tahoe hybrid's total to about 6,000 pounds.

Unlike other Tahoes, which are mostly powered by a 5.3-liter V8,the two-mode hybrids use GM's larger 6.0-liter gasoline V8 with cylinder deactivation, which shuts off four cylinders when their power isn't needed (this feature is also on the 5.3). The biggest fuel economy benefit on the highway comes from the electric motor keeping the V8 engine operating on four cylinders more than other Tahoes. In other GM trucks and SUVs we've driven with this technology, it's very difficult to keep the engines in four-cylinder mode except when going downhill or decelerating. In the two-mode hybrid, we were able to cruise most of 100 blocks down New York's West Side Highway at 60 miles per hour on four cylinders.

The price premium for the hybrid hasn't been announced. No GMC Yukon Denali or top-level Tahoe LTZ will be available.

If the 20 mpg figure ends up being comparable to our 14 mpg our non-hybrid test Tahoe returned, it will represent a huge improvement. However, most minivans can return similar mileage overall and better on the highway, ride better, and have more space inside. The only real advantage is for buyers who need towing ability and want better mileage than a typical full-sized SUV during most of their driving when they're not towing.

I wonder how many buyers interested in paying a premium to be green will get a thrill from the acceleration. Does the world really need another 6,000 pound SUV that can hit 60 mph in 8 seconds, hybrid or otherwise? And is that what hybrid buyers want?

Post your comments below. We're interested in your take.

--Eric Evarts

Comments

[miniharryc]

I saw two guys racing in 1-ton, dually diesels yesterday--one a Ford Powerstroke, the other a Chevy Duramax. You'd better believe acceleration is important, even if you're driving a Mack.

* * *

If I'm doing my math correctly, that's a 43% increase in mileage. Certain folks will always choose a full-size SUV, and anything that (reliably) brings mileage up that amount can only be a good thing.

[Mark]

This product will be a huge hit. The stigma of Minivans are a non-starter for many. Ecological/Fuel cost concerns are all that hold back the full size SUV market. This is the only one on the market. The mileage is impressive - compare it to the 08 Highlander Hybrid (25 MPG) which is mid-size and "not to be driven off road." Only surprise here is that they did not start at the premium end. Toyota/Lexus has done that with great success. Bad marketing decision there.

[Fred D.]

GM took steps to make the Hybrid Tahoe 300 lbs lighter (before adding 400 lbs of hybrid components), and more aerodynamic.

Do this across the board, GM. Making vehicles lighter and more aerodynamic will be a better net benefit than applying hybrid technology to a small number of vehicles sold. Not to mention that both those techniques result in no added complexity.

[Dave]

Sometimes people need to be able to tow trailers, and having this huge improvement in fuel efficiency for this class/type of vehicle is very impressive.
Give this 2mode and GM the credit it deserves for folks who do need to tow and want this type of vehicle but with substantially better efficiency.
The more 2modes GM sells, the lower the cost/price premiums will be, which will then in turn help make this technology more pervasive (which is a good thing)

[Miles]

20 to 24 mpg for a Full Size SUV!

That is a tremendous improvement in fuel economy. It is much better than minivans and puts the fuel economy in the range of the 6 cylinder auto trans versions of the Honda Accord and Toyota Camry (based on fueleconomy.gov information).

GM should apply this technology to its entire lineup of vehicles.

[Classic Auto Trader]

Of course hybrids won't have the power of straight gas or diesel but are great for around town driving. Good for the environment, a green solution for our planet.

Hydrogen seems to be the fuel source of the future, and it looks like Iceland's renewable energy policy is on the right track.

It sounds like the rest of the world needs to take a page out of Iceland's renewable energy book and do its part in making this world a greener place to live.

[Karsten]

What an oxymoron!

The concept of a clean SUV is beyond silly. If you care about gas mileage, don't get a vehicle that weighs this much, has such lousy aerodynamics, and is basically not designed for efficient or ecologically intelligent high speed travel. If you drive a hybrid SUV you are just trying to get away with feeling better while doing basically the same than before: Wasting resources and being too lazy/convenient/inflexible/shortsighted to really change your life and habits. You should be ashamed, just like you should be ashamed for driving a regular SUV. Obviously, this will change. It has to change just because there are not enough resources to continue doing this. Stop "green-washing" yourself - instead do something that really makes a difference. And please snap out of this adolescent mind-set that cars are something sexy and that power and acceleration matter when it some to automobiles.

[Caroll]

The only good thing about SUV's is that I can tell who the morons are so I watch out for them when I'm driving. One person in a 6000 lb tank is just stupid, and don't give me that safety crap. Look up the specs on NTSB deaths per million vehicles and you'll see that the Audi A4 is safer than the Tahoe. The only thing SuuuVeeess (calling hogs) are good for is melting them down to make electic cars and fence posts. If you have a 5000 lb boat chances are it only gets used a couple of times a year and you would use it more often if you would just keep it at a Marina and let them take care of it for you.

[Dan]

We have been looking to replace our 2000 Ford Excursion V10 with a slightly smaller, more economical SUV. I had a chance to test drive the GMC Yukon Hybrid today (5/12/08). Frankly, I was not impressed. It was easy to 'fool' the system into shutting the engine off and on, this caused a slight jerky feeling in the seat. I also noted some serious hesitation when starting from a dead stop to WOT. I would say from the time I hammered the throttle to when the engine actually started was about 1 to 1.5 seconds, and from that point until the engine actually reved up and you could feel the acceleration was over 3 - 4 seconds. Great if you never need to get out of the way of something quick. For the slight improvement in city mileage over say a Ford Expediton, I'll stick with something that MOVES when I ask it to. Besides they only offer a 7 year 100,000 mile warranty on the hybrid section of the vehicle, I can only imagine how much the battery is. The salesman even told me the vehicle will NOT run if the hybrid section fails, it must be TOWED to a DEALER!!
Give me a break GM...no wonder you are loosing money!

[Randal]

To clarify for Classic Auto Trader ... the Toyota Highlander Hybrid, at least, has more power than its gas-only sibling, as the electric drive motors on the wheels add to the combustion engine output.
For Kartsen and Caroll ... We are getting about 25-26 mpg in our Highlander (with two kids in car seats, a dog and the corresponding loads of "stuff" to haul), which beats pretty much anything else with that kind of capacity on the roads. Our last car was a Mazda Protege, so we've done the small/efficient thing, but it's not practical for a growing family. And in snow country, some ground clearance and the AWD are excellent, commonsense safety features I'm not going to find in a little urban minivan (we test drove a couple before buying the Toyota, and if we still lived in the city probably would have got a Mazda 5). So thanks for your vitriol about hybrid SUVs, but we'll keep our "silly" ride, thanks.
And finally to Dan ... what in god's name would you have to get out of the way of that quickly if you're driving one of those things the size of a small school bus, anyway?
It must have been an interesting test drive

[Burt Masepohl]

Your auto reports increasely relie on personal tastes. Please return to just the facts and let us, as consumers, determine the vehicle we are interested in. I am not interested in your opinion of hood design (Chrys Sebring) or where a bad fit is seen that it is assumed to apply across the line.

[Jeff Bartlett - Consumer Reports]

Burt - Our road tests remain as objective as ever. They can be found on the model overview pages (accessed via the pulldown menus or ratings charts). The full tech reports can be accessed in the New Car Buying Kits. Here in the blog, the Cars staff does balance our testing and survey findings with our own insights, offering some personality to compliment the objective data. Such opinion pieces are always attributed to a specific author.

In the case with Eric's blog, part of the goal was to garner feedback from readers like yourself.

On this topic, our First Drive on the Tahoe Hybrid can be found at:
http://www.consumerreports.org/cro/cars/new-cars/first-drives/chevrolet-tahoe-hybrid-suv-first-drive/overview/chevrolet-tahoe-hybrid-suv-first-drive.htm

[Jason]

I agree with Burt, I could not get through the article for the personal bias. I choose CR because they are neutral. I am not sure this type of blog helps. Save the lecture for the class room.

[mike]

We are in the process of looking for a new vehicle, due to situations within the family we need to purchase an suv...we looked into the Denali hybrid...for the high price tag we found that the front seats were a step down from the regular Denali 6 way vs 10 way, the rear lift gate does not work off the remote as in the regular Denali, the window and tail gate are one piece, so to access the rear you have to open the whole tail gate everytime. THe biggest down fall of this vehicle is it does not have a spare tire or jack and there is no room to put one because of the batteries and muffler location underneath...instead it comes with its own built in generator to plug and seal the tire...which is okay for a small puncture but incase of a blowout you are stuck with no spare tire. If you have ever had a flat tire you know how important that spare tire can be.... Of course none of the salesmen that we talked to at the different dealerships ever mentioned it....we found out by reading the small print in the vehicle booklet we got on the hybrid from the dealership...After reading Dans blog about the battery and having to be towed to a dealer this suv is not going to be sitting in our driveway....

[Adam]

I want to buy a full size SUV hybrid, I just dont know which to purchase. They have all been out for awhile, whats the best now?