By on May 5, 2020

gm

The revamped, full-size Chevrolet Tahoe and Suburban and their GMC Yukon/Yukon XL twins gain significant length, interior volume, and creature comforts for 2021, but extra MPGs seem to be in short supply.

The vehicles are now even larger than their predecessors, are still heavy, and carry identical V8 engine displacements, so no one should have expected Prius fighters. Still, the changes in fuel economy are worthy of note.

Still unlisted on the EPA’s fuel economy site, the models had their MPG figures released by GM this week. What we can see is that, while efficiency sees a gain in the city, that improvement is offset by decreased thriftiness on the highway.

It breaks down like this: in 5.3-liter, RWD or 4WD, short-wheelbase guise, the 2021 GM full-sizers rate 16 mpg city, 20 mpg highway, and 18 mpg combined. The previous-generation 5.3L short-wheelbase models earned 15/22/18 in rear-drive guise, 15/21/17 with four-wheel motivation.

The lengthier 5.3L models match these figures in rear-drive form, but lose 1 MPG in each driving cycle when equipped with four-wheel drive. EPA ratings for the old-gen 5.3L long-wheelbase models stand at 15/22/18 (RWD) and 14/21/17 (4WD).

gm

Inclusion of a standard 10-speed automatic and GM’s Dynamic Fuel Management helped the V8 manage its thirst around town, but it seems all the new added hardware (tech niceties, independent rear suspension, size) causes the hulking SUVs to imbibe more heavily on the highway. Highways are for AAA, not AA, it seems.

Opt for the 6.2-liter in either the Tahoe or Suburban, and the EPA rating comes out to 16/20/18 regardless of driveline type. No penalty here for going bigger (minus the cost, of course). The new models in 6.2L guise slightly top their predecessors in both city and combined economy.

It all sounds unimpressive, until you consider GM’s decision to offer the company’s new 3.0-liter Duramax inline-six diesel in all such models (including the Cadillac Escalade). Boasting 277 horsepower and 460 lb-ft of torque, the Duramax variants’ MPG rating remains unknown, but one look at the Chevy Silverado’s ratings suggests significant improvements in efficiency for so-equipped models. Chris was pleased with what he saw in a recent test of a new Duramax-powered Silverado 1500.

[Images: General Motors]

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63 Comments on “The Cost of Comfort: GM’s Full-size SUVs Gain Thrift in City Driving, Lose It on the Open Road...”


  • avatar
    zipper69

    It’s hard to discern a game plan here.
    Make them bigger, heavier and with no gain in fuel efficiency, do the Secret Service and Colombian Drug Lords really buy THAT many?

    • 0 avatar
      jack4x

      These are likely the most profitable vehicles sold by any mainstream automaker, what is difficult to understand about the game plan?

      No one buying these cares one bit about size, weight, or fuel economy.

    • 0 avatar
      SSJeep

      Wealthy people buy Yukons and Suburbans now. They are incredibly profitable and they sell fast. Most buyers want a little more size, and wont bat an eye at minor MPG changes. If this new model is incrementally better than the outgoing version, it will be a hit. And the diesel edition will have a lot of people jumping in from other makes. Hopefully GM doesnt mess this up.

    • 0 avatar
      bts

      The old Tahoe was really lacking in cargo and interior room. It was likely the most inefficient use of space in any vehicle.

      The new Tahoe now has about the same interior space as a minivan. But if course the Tahoe has to be several inches larger in all dimensions to have this space inside.

      As crazy as it sounds, I think GM wants these SUVs to be more competitive with the minivans and large crossovers for interior space so they made them bigger.

    • 0 avatar
      indi500fan

      When I was in NYC on vacation last year, there was a United Nations meeting of some sort in town. Many streets were closed to peons but literally loaded with black Suburbans as far as the eye can see.

  • avatar
    Zipster

    Each gallon of gasoline represents an additional 22 pounds of carbon dioxide, or more than a pound per miles. And who among the purchasers cares?

  • avatar
    Menar Fromarz

    Oh GM. Put the 3 pot into it and I would line up to buy one.

  • avatar
    krhodes1

    So with the typical Karen driving these things it will be what, 10 City, 14 Highway? Most of the SUV-driving women I know drive like they are in the Indy 500.

  • avatar
    thegamper

    I have found that most people who own these and similar vehicles will only tell you how efficient they are. Even confronted with an accumulation of real world fuel economy numbers which are significantly lower than the pie in the sky numbers they would recite to friends and neighbors. Nobody wants to admit that they made a narcissistic, sociopathic choice for narcissistic and sociopathic motives.

    • 0 avatar
      CKNSLS Sierra SLT

      the gamper-

      Your post reeks of someone who can’t afford one.

      I drive a 2018 Silverado Crew Cab I bought new.

      Listed $52,000.00 PAID $43,000.00

      Around town it gets 15mpg. Ask me if I care…….

      • 0 avatar
        Zipster

        Slt: You fit the Gomper’s description. As a sociopath you don’t care about the billions of people and animals who will suffer grieviously because of your need to affirm to yourself that you are, indeed, someone to be reckoned with.

        • 0 avatar
          28-Cars-Later

          So… am I a sociopath for fantasizing the President truly is crazy and one night wakes up and on a conference call with Premier Xi and President Putin agree to launch a strategic nuclear strike against the Third World… or am I pragmatic?

        • 0 avatar
          SSJeep

          No one really cares about fuel economy unless gasoline gets expensive. Heck one of my boats (454 I/O) probably gets 2mpg when at cruise. Ive put 220.00 in it before. I still dont care.

      • 0 avatar
        thelaine

        Dang, 15 mpg! Not bad, my old Dodge gets 12. Best vehicle I have ever owned. Luckily, “peak oil” was a hoax, and hydrocarbons are plentiful.

    • 0 avatar
      monkeydelmagico

      Not a single person who owns one of these cares about fuel economy. They never stand around at parties waiting for someone to confront them with fuel economy numbers. I suppose if some droll wretch did decide to point out their eco-transgressions they would recite anything that got them away from said dork expeditiously. Seriously who does that? They certainly are not “sociopaths” for having chosen a vehicle that does not conform to the agenda.
      Most are just happy to have a bit of disposable income and/or corporate tax shelter status in order to enjoy the finer things in life. A Suburban just happens to be one of them.

    • 0 avatar
      ajla

      I would argue that aesthetics are evidence of neither narcissism nor sociopathy.

    • 0 avatar
      Art Vandelay

      Yes. He should buy a Tesla. No narcissism whatsoever in that buyer base. Just ask them.

  • avatar
    APaGttH

    Some of the exact same members of the B&B that screamed CAFE was tyranny, unfair, putrid, and impossible to achieve are now condemning a vehicle that ignores CAFE.

    A vehicle that remains tops in its class year after year after year after year after year…

    It is quite the paradox.

    Down with CAFE!!!

    These MPGs suck!

    Har! Har! Har! Har!

  • avatar
    Master Baiter

    Currently on a road trip cross country in my X7, getting about 20MPGs on the highway at 85MPH indicated (probably 82 actual). Just paid $1.79/gallon for premium in Texas. Long live the ICE.

  • avatar
    Vulpine

    Wanna bet they changed the final drive ratios to somewhere around the mid-2.xx range? Those 10 gears are probably at such a close ratio that on the highway it’s turning 2300 revs or higher at cruising speed. That big, flat, grille isn’t going to help matters any, either.

    • 0 avatar
      jack4x

      This got me wondering. The 2020 model top gear is 0.63 and offers 3.08, 3.23, and 3.42 ratios.

      70 mph through a 32″ tire is 735 RPM at the wheel.

      The standard 3.08 axle multiplies out to ~1425 RPM in 10th. 2.XX probably makes top gear unusable below 75-80 MPH. I really hope they didn’t do that.

      If anything, they should offer a deeper gear for better performance when towing. Even 4.10 would be under 1900 RPM at 70 mph in 10th.

      • 0 avatar
        Vulpine

        @jack4x: Have to wait and see. I think I got mine backwards and meant what you just said. I do know back with Ford’s Ranger in ’97, gearing was such that the little guy got 20mpg with the 4-banger 5-speed in town and 27 on the highway but the gearing was such it had literally no oomph for acceleration even in first gear (the guy I sold it to does second-gear starts every time.) I do know it had their ‘economy’ final gear of the time and that 3.23 sounds right.

        I do think those 10 speeds in the tranny are very close ratio with quick shift points to keep the revs down while accelerating, but then that means the rear end would force high revs on the road by comparison. My ’19 Colorado only has the 3.6 V6 under the hood and while it has a lot of oomph for get up and go, the in-town mileage runs between 16.5-17.5 while highway still exceeds 26-27mpg.

  • avatar
    Hummer

    Holy Bologna I’ve never seen so many GreenPeace douchebags in one thread, do you enjoy the smell of your farts?

    • 0 avatar
      Zipster

      Hummster:

      Still guzzling the bleach? Have any government agents come to take away your AR-!5?

      • 0 avatar
        Hummer

        Guzzling the bleach? Sounds like your guzzling fake news, explains why you still believe in phony prophecies 30 years after everyone else left the ranch.

        • 0 avatar
          Zipster

          Hummster

          Your terminology is certainly getting dated: “dauchbags,” “fake news.” Don’t they teach you anything original to say in troll school?

    • 0 avatar
      thelaine

      I’m gonna go out back and burn some tires while watching the hippies form a drum circle.

    • 0 avatar

      Thank you for saying it.

      I get so sick of the environmental anxiety / hand wringers, aka little socialists dictator wannabes. Who know better how everyone else should be living and just want a dictatorship where they’re in charge and can save the world. Oh we won’t go into how capitalism is responsible for every wrong in the world. Their utopian dream is all of us in tiny homes, vegetarian, using solar, walking or bicycling everywhere and never traveling. I dunno doesn’t seem like a vision of the future I’d want.

      Besides they’re living the dream now with carona. They’re getting paid to stay home by the government and to do nothing. Which is what they’ve wanted all along. Someone to give them minimum basic income so they can live off the welfare of others.. once carona is over I suppose those they’ll have to back to living off their parents in their tiny home behind their parents house.

      These little socialists who really want to save the earth should do so by not having children. The worst thing for the environment is more people.

      • 0 avatar
        Zipster

        The Castle:

        Like so many other republicans lackey’s you don’t know the meaning of “socialism” but you use this as a general term of derision when trying to make a feeble point. By the way, why aren’t your working?

        • 0 avatar
          28-Cars-Later

          Whoa hold on, the newb is gonna school us on Republicans.

          • 0 avatar

            Just stating I’m tired of the environmental alarmism / hand wringing in all of the car mags recently. Just talk about the cars. Leave the green-peace to wired, and the right wing to brietbart.

            The suburban is a not a great vehicle, I’d never buy one. I’m always amazed at how GM can build a vehicle that is so big with yet so little interior space.

        • 0 avatar

          Socialism or, as Marx termed it, the first phase of communist society, can be viewed as a transitional stage characterized by common or state …

          In other words a transition to communism and central planning where a group of elites aka dictators tell the populace how it is they should live.

          • 0 avatar
            thelaine

            Exactly, castle. They just use whatever issue is at hand as a lever to gain more power. Apocalyptic Global Warming is a perfect example. What do you think “never let a crisis go to waste” means?

        • 0 avatar
          Art Vandelay

          Funny @zipster how one troll drops off the forum and all of the sudden…BAM…Here you are with the same views and caustic style. Wierd how that works.

          • 0 avatar
            Vulpine

            @Art Vandelay: …. Ummm… No, Art. Zipster may have the same views but he is clearly not the same person. The writing STYLE is quite different.

  • avatar
    thelaine

    I think the Lincoln Navigator is still the best looking of these big SUVs. I have always liked the GMC Yukon, but the photos here show the big door/small window/high “beltline” look that I have come to despise. For this kind of money, I would want to really enjoy the way it looks. Are safety regulations really causing all of this ugly?

    I would love an article on how safety regulations affect style.

  • avatar
    Art Vandelay

    I feel like people like Zipster are trolls past such as BAFO, P71Silvy, and BIGTRUCKS that got banned so they got a new username and doubled down. C’mon mods…let’s get this place back to where it was.

    • 0 avatar
      Hummer

      Big trucks was not that bad, he was loud and abrasive but he didn’t hide behind any user names nor could he with his personality.

      BAFO has gone through at least 3 name changes, which is ironic as he insisted that myself and DenverMike were the same person and demanded that our IP address get checked, probably 6-7 years ago. Didn’t pan out for him…

      • 0 avatar
        el scotto

        Didn’t BIGTRUCKS think he could win a fight with one of editors? @Hummer, you are correct sir; BAFO tried to use another name(s) and was called out by many on here. You and Denver Mike look at two completely different mountain ranges. BAFO would have replied with a comment about Lake Michigan or the Gulf of Mexico. I understand that P71 actually threatened someone and was banned at the corporate level.
        PCH101 quit commenting, lost Tresmonos some where along the way, and I hope Old Man Pants is doing OK. Did Deadweight give everyone two raised middle fingers and ride off in the sunset?

        • 0 avatar
          28-Cars-Later

          Tres commented a while back because we discussed something, maybe a few months ago. Not sure about The Deadweight and I haven’t seen PCH in years.

          • 0 avatar
            Hummer

            I think PCH dropped in for a comment or two either late last year or early this year.

            I think BTSR butted heads with a couple people but I don’t think he was ever outright banned He went away for a couple months (year?) came back for a year or two and then left completely.

        • 0 avatar
          Hummer

          There was also several people that were unfairly banned, I can’t remember either of their user names off hand but I almost quit both times because they were both very unnecessary bans that made the mods look like they were PMSing, one was last year and the other one was probably 4 years ago.

  • avatar
    el scotto

    From the top (and I’ve said this before) GM Truck Division is a corporate backwater for GM’s management. Their “rising stars” don’t go there. Bowling Green is its own little fiefdom. Either way, both use GM special sauce by the tanker full. The Escalade is the most “Cadillac of Cadillacs”, brash and unapologetically American. Onward to Suburbans. Sometimes you need a vehicle that can easily and luxuriously haul four golfers, four golf bags(the tour kind with room for your spikes, a rain jacket, and extra golf balls)and a beer cooler that holds at least two cases of beer. Or haul four bird hunters, four shotguns, and two dog crates comfortably. Really wanna mess with a tree hugger? https://www.sierraclub.org/sierra/pittman-robertson-wildlife-conservation-fund, that usually shuts them up. You can also tell Dylan or Colby that most sportsmen are staunch conservationists, gotta save this so there will be more. Suburbans/Navigators are also used as boat/jet ski/horse trailer haulers. Sold in upper trim levels. I know they sell LS trim Suburbans, never seen one in the wild.

    • 0 avatar
      28-Cars-Later

      “GM Truck Division is a corporate backwater for GM’s management. Their “rising stars” don’t go there.”

      So the part of the company that makes all the profit is a backwater? How interesting.

      • 0 avatar
        Hummer

        28, I actually think he’s on to something there, it used to be the premier division, I think it’s where all the misfits are sent now.

        The division has some large cracks forming.

        • 0 avatar
          28-Cars-Later

          Hmmmm, so the division making all the money is the Island of Misfit Toys these days? When should we start the death watch?

          • 0 avatar
            Hummer

            I mean what do you think?

            When the K2XX hit the streets in 2013? It was widely critiqued, a rushed refresh was completed which may have helped. The LT engines have had teething problems that are unacceptable given the high mark that the LS left off on. GM can’t decide if they want an 8 speed or 10 speed while evidence suggests that fuel economy figures have actually dropped with the new transmissions

            The new trucks are absolutely botched, the exterior is horrendous, the interior is barely even changed from the outgoing trucks, the materials feel cheap, trims levels have had their content cut in order to justify higher trim levels. No refresh is going to fix this generation of trucks. I would call this a swing and miss but the bat swung out of the batters hand upon pulling the bat up to setup a swing.

            Rumors are the GM 4 cylinder Colorado, which has proven to be the most reliable truck drivetrain currently offered is going to be cut.

            The BOF SUVs have been neutered to be BOF minivans.

            GM has the capability to be top of the field, but they have the management of a school supply chain organization.

          • 0 avatar
            el scotto

            @ 28-Cars-Later my information is dated by at least 30years. Fraternity brother’s dad was a high mucky-muck at GM Truck and Bus. He’d smile and tell us, “trucks don’t change that much and we meet sales quotas every year. I don’t have to come up with a new car and all that goes with it every year” then he’d grin wider and say “the hotshots go other places.” The GM Truck and Bus guys can say on a daily basis; this is proven, this is true. Said in that context, the fast movers/hot shots can’t/won’t/don’t come in and invent The Next Big Thing.

          • 0 avatar
            28-Cars-Later

            In my mind, based on awful product decisions GM already should have been toast or on their way out yet they persist and I thought I saw even posted a Q1 profit. Depending on how China recovers should determine GM’s short to medium turn fate, since it is a Chinese focused and probably soon to be Chinese owned company.

            I haven’t followed the C8 since launch and didn’t quite think the direction they went in was wise, but they may have proven me wrong. But besides it, the Tahoe/Suburban/Slade, and the LSx motor, what is GM anymore? They nixed Opel/Vauxhall, Holden, and a number of US marques but kept Daewoo, I think their Brazil operations, obviously what’s left in the US/Canada/Mexico with a large number of operations in China. I’m not sure who or where the new designs are coming from and I wonder if they know themselves? GMNA? PR China? The fact they are shipping the misfits to the truck division suggests either completely incompetent management *or* perhaps a long term plan to get off of truck reliance. The attitude may be, no matter how bad we frack up the trucks they still sell but we may get to a point where we cannot rely on truck profits alone to survive let alone grow (Ford is in a similar boat IMO).

            In any event, GM is no longer an American company and I think no longer a serious automobile manufacturer given all the slips of the past ten years.

          • 0 avatar
            Hummer

            Regardless of the outward perception, if the truck group stinks of a bunch of misfits, none of us can definitively point to a well polished team in any other division.

  • avatar
    PrincipalDan

    Is there still gonna be a “Custom” trim of the Tahoe?

    Give me a Custom, with the 5.3, 4×4, and towing package. I don’t need the third row and I’d prefer the front bench.

  • avatar
    RSF

    No one cares about a MPG rating on these. What matters to me, much more than ever, is how much of this thing consists of Chinese parts.

  • avatar
    Jerome10

    Do I have it right that these went from AFM (4 or 8 cylinder only) to DFM (any cylinder combo from 1-8 at any time) and went from 6 speed to 10 speed transmissions….

    And got basically zero MPG improvement?

    If so why bother?

    And if this isn’t an indication we’re scraping the bottom of the barrel when it comes to ICE and transmission efficiency gains I’m not sure what is.

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