By on February 27, 2008

dscf1176.JPGLet's get something out of the way right now: the Yukon Hybrid is over-priced. Our tester stickered at $56k. At that price point, GM's gas – electric SUV competes against BMW's enlarged X5, Audi's Q7 carcoon and Lexus' golf club friendly RX 400h (to name a few). Hybrid or no, the GMC Yukon's not exactly what you'd call an upmarket machine. If The General had taken the hit and offered the Yukon Hybrid for the same price or less than its gasoline equivalent, it would be a far more compelling proposition. But they didn't. So let's press on.

Aesthetically, the Yukon Hybrid is about as bashful as a drunken sorority girl at Panama City Beach Spring Break. The big rig's plastered with no fewer than nine proclamations that it possess a gas-electric drivetrain, including three-foot-long "Hybrid" stickers along its mighty flanks. Custom side skirts, a rear spoiler and good-looking low-weight 18-inch wheels add more not-so-subtle style (and mpgs) to the equation.

Other than that, it's a Yukon: big, bland and boxy. OK, the SUV's creases were sharpened pre-Hurricane Katrina, but the Yukon's looks still aren't going to blow anyone away.

dscf1175.JPGTo drop the Yukon Hybrid's aerodynamic Cd from .39 to .34, GM re-softened those sharpened creases with a slightly reshaped hood and rear hatch, and lost the roof rack. Although the new hood and hatch are fashioned from aluminum, the Yukon Hybrid's batteries and electric motor make it heavier than the standard model. The Yukon Hybrid's heft rises from either 5270 to 5541 lbs., or from 5438 to 5617 lbs., depending on whether you believe GM PR or the GMC website.

GM's new truck interiors may be far better than anything they've ever offered, boasting attractive chrome accents and a real woven headliner. But at $51k (base), the Yukon Hybrid's interior feels cheaper than a Las Vegas motel on a Tuesday afternoon. Fake wood and aluminum abound. Vinyl that tries (and fails) to look like leather stretches across the ample dashboard. The seats are flat and unsupportive, and the optional third row seat is unusable for anyone but Hobbits.

x08gm_yu034.jpgThe Hybrid comes amply-equipped with navigation, rear parking camera, auto climate control and power everything. In complete contrast to the exterior, only a small Hybrid logo, an "Eco" gauge and a Prius-like touch screen drivetrain display remind the driver that they're piloting the world's largest private passenger hybrid.

To maintain the Yukon's cavernous interior, the engineers utilized the undercarriage space for the NiMH batteries. Part of that space was realized (and the beast's weight gain minimized) by replacing the full-size spare tire with a can of sealant– not exactly what you'd expect in a 4×4. Not that you'd ever take those low-rolling-resistance donuts off-road. On the positive side, the Yukon Hybrid 4X4's towing capacity is a respectable 6000 lbs. (down from 8000 lbs.).

x08gm_yu037.jpgWhich may account for GM's decision to equip the Yukon Hybrid with a 332hp, 6.0-liter Vortec engine. In any case, the monster motor becomes a hybrid with the addition of a 300V battery, two 60KW motors in the transmission and some creative software.

I've never driven a full hybrid this seamless in operation. You never notice when the drivetrain changes modes, from electric to gas and back. The electric boost comes on smoothly; the power delivery remains silken as the engine spools-up. When revved hard, the 6.0-liter offered a muted yet spine-tingling burble. Despite the weight, the excellent drivetrain pushes the Yukon from zero to sixty miles per hour in about eight seconds. The system manages a decent-for-such-a-behemoth 20mpg both in the city AND on the highway.

x08gm_yu043.jpgThe Yukon Hybrid's suspension is as ridiculous as the drivetrain is sublime. The steering feels vague at low speeds and darty on the highway. Engaging four-wheel-drive mode makes the rig feel like a forklift, with all four wheels pushing in different directions. The Yukon skitters and wallows during cornering and shudders like a Sebring convertible over rough patches. The massive weight smooths out the ride to decent levels, but the European and Japanese competition put the Yukon to shame in comfort, control and cornering ability.

dscf1166.JPGAs for that highly-touted 25 percent fuel economy improvement, yes, I achieved the advertised mpg in mixed driving. But I wonder how much of that gain's down to the non-drivetrain mods. Equally perplexing: why hasn't GM incorporated them into normal Yukotahburbelades? Is the American automaker shortchanging their gas-powered SUVs to protect the hybrid versions' rep? Clearly, the Yukon Hybrid raises more questions than it answers. Meanwhile, one thing is for sure: at that price, in this market, the Yukon Hybrid will not be flying off the lots.

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82 Comments on “2008 GMC Yukon Hybrid 4×4 Review...”


  • avatar
    shaker

    “Hybrid” is a kind description of this beast; but I think the proper term: “Mongrel” was eschewed by GM brass.

  • avatar
    NickR

    a drunken sorority girl at Panama City Beach Spring Break

    Mike, I am more interested in hearing more about this than I am about this oversized, overpriced clunker.

  • avatar
    SWA737

    SIGH. Yet another example of excellent D3 engineers being forced to build mediocre products by (less than) mediocre management.

  • avatar
    frontline

    I have a 07 Denali for my 4 little urchins that will not do better than 14 MPG around town. I think a 25% improvement is off the hook!

  • avatar

    At 56K, I would buy a slightly used Infiniti M45 Sport and a used Toyota Prius.

  • avatar

    frontline:

    I have a 07 Denali for my 4 little urchins that will not do better than 14 MPG around town. I think a 25% improvement is off the hook!

    So, what if you could get, say 10 percent better mileage without paying any premium? You know, if they smoothed over your truck’s body, put it on skinny tires, lost the spare tire, added skirts and stuff and used the smaller engine?

  • avatar
    Michael.Martineck

    I wonder how many of these are destined for government agencies. Many state and federal fleets are now required to have a certain percentage of hybrids or alternative fuel vehicles in their mix. If you run a state highway, and have to have a hybrid, I guess this is something to think about.

  • avatar
    L47_V8

    Really, why didn’t they use the smaller engine? That seems like a no-brainer to me.

    Or perhaps do something shockingly un-GM and use a V6 or diesel engine?

    As it sits, this thing seems utterly pointless.

  • avatar
    RayH

    Changing aerodynamic Cd from .39 to .34 and getting rid of the roof rack seemingly could be called a green “pony” package for $1000. Skinnier tires and lowering the vehicle, in addition to the above, should result in the greatest gains in highway mpgs. The 6.0 v8 gets 27,28 highway on a Corvette, yes that’s less weight, but it’s also a lot less drag.

  • avatar
    GS650G

    At 56K it really doesn’t make economic sense to buy this for the fuel economy, it’s more about saving the planet or whatever. Two questions that come to mind are what is it going to take to fix this thing (not if but) when it breaks and why isn’t this technology being deployed in a pickup truck, something that working people use more. I mean if a small businessman can trim 25% off his fuel costs and drive it 100K in 2 years he might come out ahead financially while saving the planet(or whatever).

  • avatar
    Detroit-Iron

    Why are American men and women so afraid of station wagons? I had a Focus wagon that was bigger inside than a Cherokee, and got over 30 mpg highway.

  • avatar

    I analyzed the price of this one here:

    http://www.truedelta.com/blog/?p=200

    The premium vs. the regular Yukon is over $9,000.

    Concerning the question at the end of the review, nearly all of the fuel economy benefit is from the powertrain. The weight savings likely improve fuel economy by only a few percent. They cost too much to be worth this small benefit, at least on the regular Yukon. On the Hybrid they might keep the truck from entering the next test weight class, and thus might help the EPA numbers quite a bit even if they have just a small impact in the real world.

  • avatar
    92camrywagon

    I love the way the phrase “shudders like a Sebring convertible” links to a Chrysler ad.

  • avatar
    NN

    The powertrain seems impressive in and of itself. They could just put it in the Escalade to justify the price and differentiate the Cadillac from the rest of the GM SUV’s. I guess that wouldn’t sell enough, but I think the long term effects would be better. By the way, lose the hideously garish “hybrid” badges along the flanks have to go. They are insulting to the very customers who are purchasing these things.

    Apparently they are developing this dual-mode for smaller applications, as it is supposed to be put in the Vue next year. But that Vue will probably cost $40k. However, it will likely be applied to other vehicles with the same V-6, such as the Lambda’s, the Malibu, etc…and at some point they should find a good cost & platform combination.

    This hybrid system will be rolled out in the Silverado’s as well. I also worry about the powertrain reliability on these…sounds expensive to fix.

  • avatar
    Cavendel

    Michael Karesh :
    Concerning the question at the end of the review, nearly all of the fuel economy benefit is from the powertrain. The weight savings likely improve fuel economy by only a few percent.

    Dropping the Cd from .39 to .34 would have a huge impact on freeway mileage. Those skinny low rolling resistance tires would also be a boon. Extra weight wouldn’t affect highway mileage, but does affect the city mileage. I wouldn’t be so quick to ignore those non-drive train changes.

  • avatar
    Steven Lang

    I’m also a bit curious as to why they didn’t put this hybrid technology into the Escalade instead.

    The Yukon will have a $2200 tax credit which will bring the premium down to $6800. Different states also have some very unique subsidies, incentives, and taxpayer’s money handouts to help sell this SUV to an oil executive.

    Here’s a few hundred ‘alternative’ hand-out’s…

    http://www.eere.energy.gov/afdc/progs/in_matrx.php

    As far as the Fed’s go the Altima will have a $2350 credit. If someone can explain to me why that model has a larger federal tax credit than the Yukon please let me know.

  • avatar
    KixStart

    GS650G: “At 56K it really doesn’t make economic sense to buy this for the fuel economy, it’s more about saving the planet or whatever.”

    Then it’s about whatever, because it sure isn’t about saving the planet. Saving the planet is riding the bus, biking, walking or, if one must drive, buying a Prius or other small, thrifty car.

  • avatar
    KixStart

    Making an aero package available could be done at a small price. It probably should be optional, as it changes ground clearance and some might actually find that unwelcome (you know, the few people who actually drive these things on something other than freeways).

    And an aero package would make a big difference to the ones that are doing 20 over on the freeway.

  • avatar

    The aero package could be added as a “green option”, but if they made it standard across the entire Yukotahbureblade range, then the cost would be extremely minimized.

    The biggest problem with the aero package would be aluminum paneled SUV’s that would eventually need body work. Aluminum is very hard to work with, ask any Audi A8 owner, their vehicles are shipped off to “Audi Refurbishment Centers” when they get pranged in the side. Someone buying an A8 probably makes enough to not care (that much, as Audi gives them a free Audi loaner).

    Can you imagine your neighborhood Maaco, or other body shop trying to blend an aluminum hood with steel panels without the proper training or aluminum welders? I forsee a lot of goofy looking Yukon front ends in the future.

  • avatar
    nudave

    Hybrid? Mongrel? Perhaps bastard.

  • avatar
    Raskolnikov

    Steven Lang :
    February 27th, 2008 at 11:07 am

    I’m also a bit curious as to why they didn’t put this hybrid technology into the Escalade instead.

    They are. Its coming later this year.

    This 2 Mode Hybrid is an excellent piece. I’m excited to see it used it smaller vehicles.

    Oh, and those tacky “H Y B R I D” stickers are put on at the dealership. You don’t have to have them applied.

    I’m wondering why TTAC didn’t test the rear wheel drive version? It gets better mileage, costs less and weighs less, addressing 3 of the author’s main complaints. Maybe the RWD version would have garnered 4 or 5 stars…………..wtf am I thinking…….this is TTAC!

  • avatar
    gawdodirt

    “Engaging four-wheel-drive mode makes the rig feel like a forklift, with all four wheels pushing in different directions. The Yukon skitters and wallows during cornering and shudders like a Sebring convertible over rough patches”

    I’m going to go out on a limb here and guess that this was assumed to be an “AWD” vehicle. There IS a difference between “4WD” and “AWD.”
    4WD is not for “rough patches.” AWD is.

    Very basic, BUT, Could this generic technical oversight be applied to the rest of the article?

    Mebbe…

    Same reason I don’t comment on Nuclear Submarines…

  • avatar
    Buick61

    Why are people acting like the aero modifications, low-resistance tires, and weight reduction is something new that GM is using as a trick to make the hybrids mileage as high as posssible compared to the non-hybrid?

    The Prius does the same thing. The Honda Hybrids, too. What MPG would a Prius get without the aero cheats, low-resistance tires, and weight reduction techniques?

    Why does GM get this reaction all the time to things everyone else does?

  • avatar
    Bunter1

    Somebody should analyze this against the GM product that has already taken the “want a Tahoe” but “want better MPG” crowd.
    Lambda-bigger interior, better driver, lower bucks

    MPG can’t be far off the two-mode and I doubt the towing difference will mean squat to most buyers.

    Bunter

  • avatar
    whatdoiknow1

    I bet NYC has a order out for about 10,000 of these things already. Don’t worry GM will be able to sell each and every one of these things to one government agency or another.

  • avatar
    KixStart

    Buick61, the Prius is a purpose-built car. There’s no sheet-metal tweaks to apply to a conventional clone.

    In this case, GM demonstrated that they can lower the Cx of the Tahoe by quite a bit… why not do it to the regular Tahoe? Better fuel economy at speed would undoubtedly be a big selling point.

    I mean, the work’s already done. Do they leave the conventional Tahoe alone to make the hybrid Tahoe look better? To justify the immense investment both on their end and the consumer’s?

    GM’s public statements… they’re all about applying more fuel efficiency to the big gas guzzlers first. Well, there is some logic in that. However, if the improvements can be spread across the the big gas guzzlers at negligible cost… why not?

  • avatar
    cRaCk hEaD aLLeY

    A 56K 6.0L 332HP 2.5 TON 20MPG nature-loving economy car from the land of the brave and the free. And soon to be bankrupt too.

    Can’t you see
    It all makes perfect sense
    Expressed in dollars and cents,
    Pounds, shillings and pence
    Can’t you see
    It all makes perfect sense

    The monkey sat on a pile of stone
    And he stared at the broken bone in his hand
    Strains of a Viennese quartet rang out across the land
    The monkey looked up at the stars
    And he thought to himself
    Memory is a stranger
    History is for fools
    And he cleaned his hands in a pool of holy writing
    Turned his back on the garden and set out for the nearest town
    Hold on hold on soldier

    When you add it all up
    The tears and the marrowbone
    There’s an ounce of gold
    And an ounce of pride in each ledgers
    And the Germans kill the Jews
    And the Jews kill the Arabs
    And the Arabs kill the hostages
    And that is the news
    And is it any wonder that the monkey’s confused
    He said Mama Mama, the President’s a fool
    Why do I have to keep reading these technical manuals
    And the joint chiefs of staff
    And the brokers on Wall Street said
    Don’t make us laugh, you’re a smart kid
    Time is linear
    Memory’s a stranger
    History is for fools

    It all makes perfect sense.
    [Roger Waters]

  • avatar
    frontline

    Any good manufacturer should build a wide range of vehicles. GM should build a tiny mega MPG city car and a Chevy Suburban. They should sell 60′s style hot rods and a high line electric for the hollywood crowd. 15 years ago I couldn’t understand why I was seeing all these good looking moms driving these ‘burbans. With 4 tiny dudes , I now understand. I know gas is more expensive now but some people still need /want these vehicles. Toyota is building monsters, why can’t GM?

    Facts: My Denali XL listed for 55K I paid 43K new and

    structure does quiver over real rough stuff

  • avatar
    chronoguy

    If this truck meets it’s advertised mileage, then this is quite an IMPRESSIVE feat. You have to consider the heft,size, and displacement of the vehicle to appreciate the improvements over a non hybrid. If you drove 14,000 miles a year, you would 667 gallons instead of 1000 gallons, which would save 333 gallons.

    That is a $1332 savings a year!

    I’ve read the comparisons to other cars and it is quite an improvement. This car gets better mileage than your lux full size sedans. Can you imagine that? Better than a 7 series, or A8.

  • avatar
    Bancho

    This is impressive enough in a way, but would be a more credible effort had they used a smaller engine and worked to get weight down more. With fuel and a driver this thing is about 3 TONS of mass.

    I guess the engine part is a victim of people who want acceleration similar to being shot out of a gun. Funny though, I don’t see that many people pushing the limits of all that acceleration on my commute.

    For government agencies and law enforcement, I can see these things showing up all over the place though. I guess it will be quite the success for GM and that’s a net positive.

  • avatar
    chronoguy

    They didn’t use a smaller engine because of the cylinder deactivation.

  • avatar
    Bancho

    Why not adapt cylinder deactivation to a smaller engine?

  • avatar
    JSForbes

    A reference to PCB in an auto review? I love this site.

  • avatar
    Domestic Hearse

    Don’t miss the point.

    Forget about the Yukon H’s driving dynamics, the cost, the arguable fuel economy improvement.

    Granted, these are the things this website — and all auto reviewers — seek to evaluate, compare and comment upon.

    But that’s not the point.

    This vehicle is a marketing play, pure and simple.

    Look at those over-the-top graphics. H badges everywhere. It’s not so much that this vehicle actually saves the planet, but that GM advertises it will.

    This truck satisfies the affluent buyer’s wish to drive the tank of his/her preference, then flaunt their enlightened world-view — and their deep pockets — all at once.

    It’s also a response to GM’s late-to-the-party green position relative to Toyota. Does GM have a decent small vehicle to into which to drop their (recently reviewed and critically assessed) Hybrid technology)? No. But GM does have trucks and SUVs people still buy (at a declining rate). The logical solution — put their Hybrid system where their buyers are. Trucks.

    So is the Yukon Hybrid (and its sister, the Tahoe H) a pig? In terms of real-world driving and gas consumption, you bet. But the fact of the matter is, this oinker’s got H-lipstick on it. And that marketing/PR twist is the only reason for its existance.

  • avatar
    chronoguy

    So is the Yukon Hybrid (and its sister, the Tahoe H) a pig? In terms of real-world driving and gas consumption, you bet.

    I would have to argue with you.
    I had a Chevy truck from the 80s that did 10-11 mph tops from a 120 hp engine. So in 20 years, they basically double the displacement and efficiency.

    This SUV does better mileage than my real world station wagon with all that heft. I guess you never owned or drove a 5,000 lb SUV before.

    As for trucks, this is coming. However, unlike the trucks – Silverados, F-250s, large SUVs don’t have Diesel. You can get a Silverado in diesel but not a Yukon. The market (apparently) does not want diesel in their SUVs. So who cares if this is a marketing gimmick. It works as advertised and that is impressive in itself.

    $56,000 is really small change for a Yukon.

  • avatar
    quasimondo

    Why not adapt cylinder deactivation to a smaller engine?

    I did some searching and the general consensus is that with the 6.0 engine, the additional torque allows it to run in four-cylinder mode longer than you would with the 5.3 engine.

  • avatar
    seoultrain

    It’s pretty funny that the article makes fun of the Sebring in this article, and there’s a mouse-over ad on “Sebring convertible”.

    TTAC: “Hey Chrysler, your car sucks, but thanks for the money.” *cha-ching*

  • avatar
    blautens

    People are going to buy SUVs whether they are gas or hybrid (well, at least GM hopes they do). Why not offer a full size SUV in this format?

    What if all the GMT900 SUVs out there could improve their overall MPG by 50%? That would be great, right? This is a tiny, small start. Refine the technology, learn, apply it to other platforms…

    I don’t see quite the downside to this that others see. I’ve driven both the extended GMT900s and the extended Ford (well, the Lincoln) SUVs for a couple of weeks each as rentals. I wouldn’t necessarily buy them myslef, especially as strictly kid haulers, particularly the GMT900s, because the live axle compromises third row packaging, but if you’re like my neighbor and tow a large boat and pack the SUV with people, why not buy one and make it the hybrid version?

    Options are good, right?

  • avatar
    Jordan Tenenbaum

    Robert Farago :

    So, what if you could get, say 10 percent better mileage without paying any premium? You know, if they smoothed over your truck’s body, put it on skinny tires, lost the spare tire, added skirts and stuff and used the smaller engine?

    I’m waiting for the moment someone does this, as I have a feeling they could achieve close if not the same mileage as the Hybrid.

  • avatar
    James2

    and the optional third row seat is unusable for anyone but Hobbits.

    Professional grade or not, Hybrid or not, this is just poor engineering at its finest, considering the size of this beast.

  • avatar
    KixStart

    In re, “Why the 6.0?”

    I think GM also did the late-closing valve trick on this engine, so that you get somewhat improved efficiency. I could easily be wrong but I could swear I read that somewhere.

    Of course, the question is still, why not use the smaller engine and apply whatever trickery to it seems appropriate? Less weight, etc, etc, and get any extra torque that you might need from the electric motor only when you need it.

    Ideally, if they can get cylinder deactivation working on their 6.0, roll it down to the other motors. Ditto the late-closing valves (if I’m right about that; it is definitely a trick Toyota is using).

  • avatar
    revved

    I consider the interior outstanding. Even better then my Audi TT.

    I have removed all of the exterior Hybrid stickers on mine, and think it looks even better then the Danali.

    The bigger engine is used because it can spend more time in 4 cyl. mode then the smaller 8 can, which is why it gets better highway mileage then the 5.3, which “gives better economy” I’d like to know when it gets better economy.

    The weight savings methods are not used on the standard Yukons because they do not get the $2200 federal tax credit to help offset the extra cost.

    Oh, and most of the local dealers have 6-8 week waiting lists…

  • avatar
    Edward Niedermeyer

    chronoguy: The market (apparently) does not want diesel in their SUVs.

    Bingo. Put the new Duramax diesel in there, and your fuel efficiency is comparable to the hybrid with a good couple grand off the stickershock. Maybe GM thinks (bio)diesel hurts its illogical marriage to ethanol… honestly, I don’t understand it. Sure diesel costs a little more per gallon, but once the government starts handing out tax credits for clean diesels like the Duramax, you’ll see it in the Yukotahburbleblabla.

  • avatar
    Kman

    LOL @shaker! “Mongrel” certainly is the more accurate descriptor.

  • avatar
    Kman

    It’s the price-point. Here’s a direct competitor that negates the existence of this Yukon Hybrid:

    The Mercedes-Benz GL320CDI

    Priced around 53-57K, it is rated at 18/24 MPG, provides true seven-passenger seating, and interior packaging that any body-on-frame can only dream of. My quick search of its towing capacity found either 5,000lbs or 7,500lbs, either way within the same region as the Yukon’s.

    So, let’s add this one to TTAC’s de-facto running list of “what’s the point of this vehicle?” vehicles:

    - GMC Yukon Hybrid
    - Lexus LS600hL
    - Cadillac Escalade EXT
    - Lincoln Mark LT
    - Hummer H2 SUT (‘Slut’)
    - Lexus RX400h

    … which ones am I missing?

    On that note, I submit the Infiniti EX35. As sexy and luxurious as it is, it’s an SUtilityV with a rear-seat smaller than an Aveo’s.

  • avatar
    crf450

    Just to let ya’ll know, their is another article on the Tahoe. When they test drove that, it was getting around 26mpg.

  • avatar
    crf450

    Those of you commenting on the engine being heavier, thats false. The engine is an aluminum block v8. So its much lighter than the iron block 5.3

  • avatar
    crf450

    “I guess the engine part is a victim of people who want acceleration similar to being shot out of a gun. Funny though, I don’t see that many people pushing the limits of all that acceleration on my commute.”

    Well when you have a vehicle thats 5,000+lbs, it needs that power to accelerate decently and tow a hefty load. But it is in no way considered fast with an acceleration of 8 seconds 0-60. A car that weighs 3400lbs with a similar powered engine can do that in 5 seconds. A sub 3500lbs car with a 200hp engine can do 0-60 at around 7 seconds.

    People, just because this has a 300+hp v8, doesn’t mean it going to accelerate like a hotrod.

  • avatar

    I have amended the review and deleted the following text.

    Which may account for GM’s decision to equip the Yukon Hybrid with a gargantuan, 332hp, 6.0-liter Vortec engine (the 5.3-liter powerplant revs easier, weighs less and gives better economy).

    Thanks to our readers for keeping us honest.

  • avatar
    frontline

    “Put yourself in their shoes” C’mon guys ,its real when I’m talking about needing room in a vehicle. Hecht, the Tahoe is really too small for a family with 4 children and friends or in-laws. I bought the biggest Thule they make for my Denali XL for the trips to the beach and I use every cubic inch of space. Sure I could have bought a minivan but 2 or 3 more MPG ain’t enough to compromise.

    Revved, I’m with you man . I drove 1,000 miles to Florida and my big Hoss was like a freight train and burned less fuel per person than Jet Blue.

    The new small Duramax is coming to the 1/2 ton platform any minute now and it is awesome!

  • avatar
    ctoan

    I think the big engine thing is probably a way of completing the image that this vehicle represents: You can have a hugeass vehicle and still be green(ish), without any compromises.

    Had they put a smaller engine in, it would have diluted that image.

  • avatar
    Bancho

    The new small diesel V8 would have been the superior engine by far. Even sans the hybrid system it would be more efficient. With the hybrid system it owuld be pretty impressive. I’m sure this would have taken the price from “really high” to “simply ludicrous”.

    The price on these things is nuts though. I’ve got two newer vehicles (’06 Frontier XE and ’08 xB) that together cost about 60% what this thing lists for (and yeah, I realize no one pays MSRP for a domestic).

  • avatar
    rudiger

    shaker:“Hybrid” is a kind description of this beast; but I think the proper term: “Mongrel” was eschewed by GM brass.”Reminds me of the sixties when Pontiac’s ad agency wanted to refer to the GTO as a ‘Goat’ in an ad (the ad’s captian was “A Boy and His Goat”).

    The GM execs were incredulous, saying that they couldn’t call one of their cars a ‘Goat’. They had no idea that Goat was not a dissmissive term but simply the normal street-slang for the GTO.

  • avatar

    RF,

    I DID mean the 5.7 from the Corvette and other applications, not the 5.3 from the regular Yukon. The 5.3 is much heavier than the 6.0, and does not rev easier… its an ancient engine, and not suited to this application. The 5.7 is probably GM’s best design at the moment, and since the cylinder deactivation isn’t very hard to do, they can easily adapt that to the hybrid.

  • avatar
    smokeyburnout

    @ Mike Solowiow:

    You are mis-informed on several counts. The 5.7L engine in the Corvette has not been produced since the C5 (2004 model year). The current Corvette base engine is a 6.2L (and before that, it was a 6.0L).

    I don’t understand what you mean by an engine “revving easier”- these engines are all the same basic geometry, primarily just a displacement difference. The higher the displacement, the easier it should rev (more torque = faster 0-60 = faster engine revving).

    Also, GM makes an aluminum block 5.3L, which should be close in weight to the aluminum 6.0L. They also make iron block versions of both displacements, which are virtually identical, just with a different block material. Not ancient engines at all.

    Also (mistake #3)- the hybrid DOES have cylinder deactivation.

    Please do some research before you go spouting off incorrect facts.

  • avatar

    Smokeyburnout:

    I appreciate the effort to keep me honest, it’s readers (and commentators) that aren’t afraid to take-on the reviewer that make this site great, but lets address the mistakes.

    1. I have never driven the 6.2L, so I cannot speak to it. I have driven the 5.7L in several different machines (Corvette, GTO, etc….) and am always impressed by it. GM can easily resurrect it. The 5.3 in the regular Yukon is iron, heavy, and ancient. Non-ancient would be the Northstar… but GM killed it.

    2. High displacement usually means more difficulty in reaching upper revs. More torque helps, but that torque must also overcome the greater reciprocating mass, whether GM enhanced the stroke, or bore. If higher displacement meant an easier time reaching higher revolutions, then 4-cylinders should have a much harder time reaching the 5500rpm’s the V-8′s usually redline at (referring to domestic).

    3. I know the 6.0L features cylinder deactivation. In the previous post, I meant the GM should find it easy to add cylinder deactivation to the 5.7L, since it was never offered with it, and they offer it on nearly all the rest of their current V-8 lineups.

    Keep reading the site, and I expect all the readers to try to find flaws with my work. After all, if you don’t seriously address your own faults, how can you criticize the work of others?

  • avatar
    crf450

    Their is an aluminum block 5.3 used in the Silverado/Suburbans and their GMC counterparts I believe, but their not used in other vehicles. I think the 5.3 A/B LS4 used in the Monte Carlo SS and other cars of the same platform was a different engine, since those cars were fwd.

    I think GM went with the 6.0 for more torq, so that makes it easier to run on 4 cylinders.

  • avatar

    crf450:

    Your research is correct. GM currently offers 4 versions of the current 5.3L, two iron-blocks, and two aluminum. And I believe GM used the 6.0L to offer more towing capacity, not to keep in 4-cylinder mode more often, but I’m not a GM engineer/head honcho, so only they know for sure.

    Here’s the breakdown of the GM 5.3L offerings:

    At present, four versions of the 5300 are in production: 2 iron block versions (LY5 and LMG) and 2 aluminum block versions (LH6 and LC9). All versions feature the Active Fuel Management system.

    The LH6 (Aluminum) with Active Fuel Management replaced the LM4 for 2005, and was the first of the Generation IV small block V8 truck engines to go into production. It is the aluminum block counterpart to the LY5.

    LH6 applications:
    2005-2007 Chevrolet TrailBlazer including EXT
    2005 GMC Envoy XL
    2005 GMC Envoy XUV
    2005-2007 Buick Rainier
    2005-present Saab 9-7X
    2007 Chevrolet Silverado 1500
    2007 GMC Sierra 1500

    Introduced in 2007, the LY5 (iron-block) Vortec 5300 is the replacement for the LM7 Generation III engine. For SUV applications, it is rated at 320 hp (239 kW) and 340 ft·lb (461 N·m) of torque; for pickup truck applications, it is rated at 315 hp (235 kW) and 338 ft·lb (458 N·m) of torque.

    LY5 applications:
    2007-present Chevrolet Avalanche
    2007-present Chevrolet Silverado 1500
    2007-present Chevrolet Suburban 1/2 ton
    2007-present Chevrolet Tahoe
    2007-present GMC Sierra 1500
    2007-present GMC Yukon
    2007-present GMC Yukon XL 1/2 ton

    The LMG (iron-block) Vortec 5300 is the FlexFuel version of the LY5. Horsepower and torque ratings for SUV and pickup truck applications are the same as each application’s LY5 rating.

    LMG applications:
    2007-present Chevrolet Avalanche
    2007-present Chevrolet Silverado 1500
    2007-present Chevrolet Suburban 1/2 ton
    2007-present Chevrolet Tahoe
    2007-present GMC Sierra 1500
    2007-present GMC Yukon
    2007-present GMC Yukon XL 1/2 ton

    The LC9 (Aluminum) Vortec 5300 is the FlexFuel version of the LH6, and is found in 4WD models. SUV applications are rated at 310 hp (231 kW) and 335 ft·lb (454 N·m) of torque.

    LC9 applications:
    2007-present Chevrolet Avalanche
    2007-present Chevrolet Silverado 1500
    2007-present Chevrolet Suburban 1/2 ton
    2007-present GMC Sierra 1500
    2007-present GMC Yukon XL 1/2 ton

  • avatar

    This vehicle concerns me. I like the 20 mpg rating, definitely. But there are two things I don’t understand about it.

    First, there are lots of other SUVs that get 20 mpg, and most have some or all of the traits in this vehicle. You have the RAV4, which has three-row seating, a lower price, better reliability, and probably more offroad ability simply because it’s smaller and easier to maneuver, as just one example.

    The second reason I don’t like this is because it calls GM’s attention away from its terrible small trucks and SUVs like the Chevy Colorado and Equinox. As long as these little trucks get the same fuel economy as the other trucks in their class, there’s little reason for them to exist, since the others are so much better in nearly all regards. This technology would help, but I don’t know if GM is putting enough effort into getting those vehicles more fuel-efficient powertrains. The fact that they’re putting so much into this while Colorados still do without V-8s or even V-6s makes me doubt that they’re even considering a hybrid (or much of an update) for either the Colorado or the Equinox.

    I suppose the question is, why did they bother with this while their other vehicles are struggling so badly? Green cred aside, what’s the point?

  • avatar
    crf450

    “Mike Solowiow: And I believe GM used the 6.0L to offer more towing capacity, not to keep in 4-cylinder mode more often, but I’m not a GM engineer/head honcho, so only they know for sure.”

    Very plausible point. My side of it was, since it’d turn off 4 cylinders, the others would have to work harder thus burn more gas to turn the dead mass in the other half of the engine. The extra displacement of the 6.0 would help alot in that department, it wouldn’t have to work as hard as the 5.3.

  • avatar
    smokeyburnout

    Mike- thanks for the prompt and well researched response! I have no more issues with your facts, but want to question your opinions from your previous post.

    1. You say the 5.3L iron block is is heavy and ancient. Yes, it is heavier than an aluminum block. But there are versions of aluminum 5.3L that GM makes, and puts in trucks (even in the Yukon!). Also, I’d be interested to see the weight comparison between an iron block pushrod engine and a DOHC aluminum engine. Those three extra cams and larger heads add alot of additional weight.
    As far as the 5.3L being “ancient” – you seem to imply that the 5.7L is superior, and GM should use the 5.7L, but add cylinder deactivation. The 5.7L is a “Gen3″, whereas the 5.3L in the Yukon is a “Gen4″. I am familiar with both of these engines, and there are not very many major differences between them – both are OHV, pushrod, etc. It was an incremental upgrade (Gen 4 essentially added cylinder deactivation, changed the cam sensor from the rear to the front, etc). Therefore I don’t quite understand your reasoning. Maybe I’m reading too much into your love of the 5.7L?

    How can you compare a 5.7L engine in a car, to a 5.3L engine in a truck? The weights are vastly different. An engine with the same power/torque in both a car and truck will feel much more powerful in the car, as it is lighter.

    And your comment: “If higher displacement meant an easier time reaching higher revolutions, then 4-cylinders should have a much harder time reaching the 5500rpm’s the V-8’s usually redline at” – If you were to put a 4 cylinder in a truck, I can assure you it would have difficulty reaching the 5500 redline you mention. As the engine speed is related to vehicle speed (through the transmission), the faster you can propel the vehicle, the faster the engine rev’s will rise. More torque will make the vehicle go faster, and therefore the engine’s rev’s will rise more quickly. If you were to do a drag race between a 5.3L and a 6.0L GM truck, the 6.0L would “rev faster” as well as win the drag race.

    I am probably babbling at this point, but I think you get my point. Compare engines between vehicles of similar mass. It is difficult to compare a 4 cyl Subaru WRX engine to a V8 corvette engine to a V8 truck engine. Different Hp/weight ratios, etc.

  • avatar
    crf450

    The Luigiian, the colorado’s are indeed crap trucks, mostly because of the poor choice going with a inline 5cyl instead of a good v6, or maybe even a v8. Hell, GM built an SS Colorado concept, that had the 400hp LS2 and the T56 6 speed tranny. They made a huge mistake scrapping that idea, cause it would have sold like hotcakes to those who want a high performance truck. I like the looks of the colorado, but its current power train sucks. Its base 4cyl motor is really good though compared to other 4cyl equiped compacts.

  • avatar
    smokeyburnout

    @ crf450:

    The higher displacement of the 6.0L engine would allow it to stay in 4 cylinder mode longer than the 5.3L engine. It would have more torque, when the 5.3L “runs out” of power, the 6.0 has more in reserve. This may actually allow it to be MORE fuel efficient than the 5.3L engine – only GM’s engineers know for sure.

    But I’m sure towing capacity was considered as well. People buying this vehicle aren’t interested in compromising their vehicle’s capability just to get better fuel economy. They still need to tow boats, campers, trailers, etc.

    Also, to respond to your previous comment, the FWD version of the 5.3L engine is very similar to the truck version. A few changes to the water pump/etc to allow it to fit between the fenders were necessary, but the internals are the same. Note the FWD engine has cylinder deactivation as well.

  • avatar

    Smokeyburnout:

    The weight difference between the iron and aluminum blocks (5.3L) is 60lbs (according to the GM Performance website), which is quite significant. The 6.0L weighs only 22lbs less than the 5.3L. I can’t find the corresponding transmission weight differences. A OHV compared to a OHC is about 100lbs (in favor of the OHV, Vortec vs Triton)

    I have driven a Gen-1 5.7L in a GMC Sierra, and really liked it, and was even more impressed in the GTO application. I like the 6.0L even more, and the 6.2L makes angels descend from heaven.

    However, if you’re only aim is economy, the 5.7L with Gen IV technology should have been the engine to use. It has a better reliability history than the 5.3L (opinion only, but the 5.7′s used by Occidental Petroleum in the Permian Basin lasted much longer than the 5.3′s), and with the Corvette flywheel and transmission components (from the C5), it would have a much better time coping with the hybrid drivetrain, and the off-on-off-on city driving.

    GM currently doesn’t offer the aluminum 5.3L in the Yukon or Tahoe, they only offer it in the Suburban/Yukon XL (only talking SUV’s). I have no idea why.

    And all the Vortec’s really are ancient designs. OHV in the 21st century? Come on! The only reason I see staying with a push-rod would be towing and low-end torque, but Ford has proven this wrong with their OHC Tritons. The 5.7 is less ancient than the 5.3 in that it incorporated a modern intake design, advanced combustion chambers, and several other goodies.

    As for the torque vs. reciprocating mass argument, the 4-cylinder was an extreme argument, so lets use a scenario I’m very familiar with.

    The previous gen BMW M-3 used a straight-6 design. It was well known for its free revving nature. The current gen-M3 uses a V-8. The cars are within a couple hundred pounds of each other, with horsepower differences of 60bhp (approximately). A different application than small-block V8′s I know, but bear with me.

    Even with the power advantage, BMW had to significantly lighten the S65 V-8 engine components to maintain the signature M3 feel, a free-revving, high rpm autobahn burner. Even though the v-8 had a lot more torque, and just as much weight to pull around, the V-8 just simply didn’t sing like the straight-6, so they lightened the pistons, crankshaft, and adjusted the VANOS to compensate.

    All things being equal (including horsepower), the larger the displacement, the harder it is to rev, simple physics of mass. The only way correct the problem is a lot more horsepower (and not just 10 or 20bhp), whether forced induction, variable intake/exhaust, or the tooth fairy. So if you don’t want to drastically increase the power (and reduce your mpg’s), you go with a slightly smaller, more rev happy engine, a la 5.7 vs 6.0.

    Opinions really, but I could argue cars all day (and all night apparently), which is why I love TTAC. Where else can you argue semantics with the authors? C&D would laugh at you!

  • avatar
    crf450

    Mike, that remainds of the post I made for the ZR1 Vette.

    “Awsome post phil! I completely agree about the hp/L arguments, its a ricer argument for those tuner boys that dont know much about engine physics and such.

    The reason that smaller v6’s and 4cyl make good power for their size is

    1:Good flowing cylinder heads using DOHC design.
    2:High revving rpms with the smaller displacement.

    GM could also use the DOHC design and get much higher output from their v8’s. Problem is, the engine will be much bigger and heavier than a smaller, lighter, and more compact pushrod v8.”

  • avatar
    Paul Milenkovic

    The hybrid technology by itself is no magic bullet and was never intended nor expected to get leaps of gas mileage all by itself. That the Prius gets such high (cough, EPA numbers) is a combination of the hybrid drive, the hard skinny tires, electric power steering, goofy styling but ultra-slippery aerodynamics, the hot water bottle engine preheater, and driving it in low-intensity stop-and-go where the hybrid drive is optimized. When my brother in Florida bombs along at 80-per with the rest of the traffic to take the kids and mother-in-law to Orlando, he gets pretty much the same mileage as I get out of the old Camry he sold me when I drive legal speeds under the watchful eyes of the Wisconsin State Patrol, making sure those Illinois people don’t get ideas. A Corolla gets x-MPG and a Prius gets x-MPG plus some increment epsilon (sorry, math talk). A Yukon gets Y-MPG and a Yukon hybrid gets Y-MPG plus epsilon. I guess we can argue until the cows come home (Wisconsin talk) about whether a Yukon is a vehicle anyone would want to drive or whether everyone in the market for one should downsize into an Acadia (or even a Prius for that matters). But whether an SUV Yukon makes any sense to anybody given that there is the the CUV Acadia is a completely different issue than the hybrid drive. Maybe the issue everyone is getting at is that if you gorge yourself on a high-calorie “King’s cut” prime rib dinner, saving calories by getting the low-cal ice-milk dessert is a false economy.

  • avatar
    EJ_San_Fran

    With compromised towing capacity of only 6000 lbs what’s the point of a heavy body-on-frame SUV?

    Note the way GM calculates towing capacity: it includes all passengers and cargo inside the vehicle. So, if you have 1000 lbs of passengers and cargo the towing capacity is really only 5000 lbs.

    That’s the same towing capacity as a Toyota Highlander CUV, which is listed as 5000 lbs, excluding passengers and cargo.

    So, this large hybrid has the towing capacity of a mid-sized SUV, less seating comfort and interior space than a minivan, uses a lot more fuel than other hybrids and is very expensive without being a luxury vehicle.
    Is that supposed to turn on a lot of soccer moms?

  • avatar
    BEAT

    Smokeyburnout

    Aluminum Block engines are a little noisy. I noticed that with my 4B11 engine. It is light weight but with a little noise in the cabin. especially for the driver.

    Probably it’s so light weight that the noise coming from the piston can be heard.

    I’m just wondering with the V8 Aluminum block it might be louder than the original big block engine.

  • avatar
    jthorner

    $56K for a pickup truck with the bed swapped out for seats? They lost me right there.

  • avatar
    jthorner

    In the truck markets where they are available diesels are VERY popular. Ford claims to have sold well over 1 million diesel Super Duty in just the past six years.

    The reason nobody buys diesel SUVS or standard sized pickup trucks is because they are not available, yet.

  • avatar
    quasimondo

    Why, oh why are we still doing apples/oranges comparisons between a Highlander and a Yukon? This makes as much sense as comparing a Civic Si to a Corvette Z06.

    Note the way GM calculates towing capacity: it includes all passengers and cargo inside the vehicle. So, if you have 1000 lbs of passengers and cargo the towing capacity is really only 5000 lbs.

    Whoever gave you that information is incorrect.

    The figure you want to look at then is the Gross Combined Weight Rating (GCWR) which is gross vehicle weight rating (GVWR) + maximum towing capacity.

    For a Tahoe, the GCWR 13,700 lbs. With a curb weight of 5835 lbs, a GVWR of 7700 lbs, that leaves and additional 7783 lbs remaining for available towing. That means, even with a maxed out trailer, it’s still rated to carry over 1500 lbs of passengers and cargo. Somebody correct me if my math is wrong.

    Towing capacity is not compromised by extra cargo.

  • avatar
    Skooter

    “Note the way GM calculates towing capacity: it includes all passengers and cargo inside the vehicle. So, if you have 1000 lbs of passengers and cargo the towing capacity is really only 5000 lbs.”

    Flat out wrong. Yukon Hybrid trailering capacity is 6,000 lbs period. Combined weight rating is 12,000 lbs.

  • avatar
    Skooter

    …and by the way, the Toyota Highlander hybrid max tow capacity is just 3,550 lbs. Please examine the facts before making declarations.

  • avatar
    IronEagle

    # jthorner :
    February 28th, 2008 at 3:02 pm

    In the truck markets where they are available diesels are VERY popular. Ford claims to have sold well over 1 million diesel Super Duty in just the past six years.

    The reason nobody buys diesel SUVS or standard sized pickup trucks is because they are not available, yet.

    I don’t know about that. I had my folks pick up a CRD Liberty Diesel which gets 26mpg on the highway and was the best SUV value of the past 10 years. You got the Venturini italian built 2.8 CRD with a variable geometry turbocharger and the Ram’s 5 speed “Orion” transmission for only $1200 more. Daimler-Chrysler blew it when they moved the CRD to a V6 in the $42k Cherokee then didn’t offer it in any of the more affordable trim levels.

    The Cummins Turbo Diesel with only a 4 speed auto vs 5 speed Orion in my Hemi Ram was an over $5000 upgrade. Not worth it to me as I still got the Heavy Duty frame, Dana rear end, 14 inch 4 wheel disc brakes etc. Plus just the Cummins is over 800lbs heavier than the Hemi.

  • avatar
    L47_V8

    KixStart :
    February 27th, 2008 at 5:57 pm

    In re, “Why the 6.0?”

    I think GM also did the late-closing valve trick on this engine, so that you get somewhat improved efficiency. I could easily be wrong but I could swear I read that somewhere.

    Of course, the question is still, why not use the smaller engine and apply whatever trickery to it seems appropriate? Less weight, etc, etc, and get any extra torque that you might need from the electric motor only when you need it.

    Ideally, if they can get cylinder deactivation working on their 6.0, roll it down to the other motors. Ditto the late-closing valves (if I’m right about that; it is definitely a trick Toyota is using).

    To my knowledge, the 5.3L V8 in the trucks doesn’t use variable displacement, but the 5.3L V8 in the cars (Impala SS, Grand Prix GXP, LaCrosse Super) does have this system, so although it’s applied differently, GM has already implemented this system on smaller V8s.

  • avatar
    Buick61

    L47_V8:

    “To my knowledge, the 5.3L V8 in the trucks doesn’t use variable displacement, but the 5.3L V8 in the cars (Impala SS, Grand Prix GXP, LaCrosse Super) does have this system, so although it’s applied differently, GM has already implemented this system on smaller V8s.”

    It’s been covered in the comments already, but, yes, the 5.3L V8 in GM trucks has cylinder deactivation. They first had it in August 2004 on the 2005 GMC Envoy and Chevrolet Trailblazer extended wheelbase models with the V8.

  • avatar

    @detroit iron

    hear hear! but it seems as if the automakers have no room for the station wagon anymore. mazda scrapped its pleasing 6 wagon, ford chucked the focus and taurus wagons. there are a few wagons remaining – the saabs, the volvos, the audis – but few can be had for below $35k.

    the trend definitely is to phase out the wagon in favor of the SUV or the odd-looking and hardly more fuel efficient “car-UV,” though with current and forecast fuel prices, i bet both consumers and the manufacturers will regret leaving the wagon behind. instead consumers are faced with monstrosities like this yukon abomination.


    # Detroit-Iron :
    February 27th, 2008 at 10:28 am

    Why are American men and women so afraid of station wagons? I had a Focus wagon that was bigger inside than a Cherokee, and got over 30 mpg highway.

  • avatar
    doctor olds

    There is NO vehicle competitive with the Yukon (& Tahoe)Hybrid when capability is weighed in. These trucks meet the needs of active families and save far more fuel compared to traditional powertrain equivalents than small hybrids cars. There are NO hybrid vehicles that pay for themselves, however, even at today’s gas prices. I noticed no comments about the high price of the Toyota Sequoia, at $15,000 more than this remarkable hybrid!

  • avatar

    @ Doctor Olds,

    The Sequoia is only $4K more than our Yukon Hybrid as tested, not $15K, and that was the most expensive model. Add in a few more options on the Yukon, and they reach parity, yet the Sequoia has more “toys” (disregarding the very good hybrid powertrain). Factoring in base prices, the Sequoia and Yukon (non-hybrid) are almost the same.

    And there are many vehicles competitive with the Yukon Hybrids. If you want the space and towing capactiy, get an Audi Q7. Want more luxury for the same price, get a BMW X5. Want a hybrid thats built better and gets fantastic mileage, while still having about 70% of the space, get a Lexus RX400h.

    The Yukon is a good car, not a great car. But GM should not have passed on the development cost of the hybrid powertrain onto the consumer. That puts the build quality of the Yukon in a realm it cannot compete in, and a demographic that doesn’t care that much about gas prices other than a warm, fuzzy feeling that they are “saving the planet”.

  • avatar
    vap3

    well said mike solowiow, you even got the dimensions right! haha

    I wonder those who bought one if they are happy with the vehicle, and if anyone really tried to get the best tank with it. I heard slapping it in N forces auto stop but you can still coast, if that’s the case I don’t understand how you can take advantage of physics and get kick ass mileage! THAT”S BIG TO BOOT!

  • avatar
    jstnspin82

    This is what happens when engineering goes down the drain. Either costs are cut and the engineers are limited to what they can or can’t do so they don’t waste time trying and therefore poorly engineered vehicles are marketed and sales go down because for the same price as this piece of crap you can buy a finely engineered BMW X5, AUdi Q7, Toyota Sequoia, or a Lexus RX 400h. Then GM has the intelligence to hybrid such a heavy gas guzzling SUV. They engineered the Escalade to so you can be cool and think you are saving the planet to. What’s next for GM, are they going to hybrid a Tank?

  • avatar
    jstnspin82

    What is GM’s next move, are they going to Hybrid a tank and sell it to the Army?


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