After I started this article, it sat languishing unfinished for quite awhile as other priorities came along. I decided to revisit it and finally hit the Submit button after reading the recent article in praise of the 2000 Chevy Suburban. I’m a little late for this to be a “new vehicle” review since the Yukon was updated for the 2015 model year.
About a year ago now, in the spring of 2014, I had the opportunity to drive a 2014 GMC Yukon for three weeks. It’s not often that I drive a vehicle that doesn’t personally belong to me or my wife, much less for such a long term. I decided to write a review of it compared to our other vehicles.
I was renting the Yukon because my 1994 Dodge RAM2500 with Cummins turbo-diesel (CC here) was in the bodyshop. We had a major ice storm in the winter of 2013-14, and a fallen tree branch caused some minor damage to the roof, hood and windshield. I was hopeful to get a new RAM1500 pickup as a rental, but unfortunately there were none available.
The 2014 Yukon was the last model year of a 7-year design cycle. I found this Yukon looks extremely nondescript; the metallic beige paint doesn’t help either. I much prefer the looks of the previous 2000-06 iteration Yukon, or the next generation Yukon that followed this, or even our 2006 Honda CR-V.
The driver’s seat in the Yukon is quite possibly the most comfortable vehicle seat I’ve ever sat in. Some living room furniture isn’t this good. The seats in our CR-V could possibly feel this comfortable IF they were wider. The armrest in the door and the center console are also at the right height and distance to rest my elbows on comfortably. Initially I felt that the steering wheel was too far away, and was disappointed that the column does not telescope (it only tilts). I got used to it after a few days and found a comfortable way to hold the wheel.
Even when the driver’s seat is adjusted for me, there is still adequate room for another adult to sit behind me in the second row. The middle bench seat has child seat LATCH anchors provided for two seats, the middle and passenger positions. I found the lack of LATCH anchors behind the driver’s seat cumbersome. We installed my daughter’s carseat in the middle location. I have to climb right in to buckle her into the seat.
My son is of booster-seat age. I figured he would enjoy the novelty of riding in the third row, and I was right. The first time he rode in the Yukon, he announced, “When I grow up, I’m buying one of these!” The third row only seems suitable for kids, as it is awkward to climb into and the seat is located right on the floor, with no footwell.
After a trip to Costco, we also found that there was barely room to put our purchases behind the back seat. We flipped one half of the seat down to make room, and our son was surrounded by groceries. If you need three rows of seats AND cargo room at the same time, you’d be better served by the longer Yukon XL/Suburban instead. We like to go on tent camping vacations, and I think I would’ve been disappointed trying to pack all of our gear into this truck.
New SUVs all seem to be designed with a back door that lifts like a minivan. I much prefer barn doors like my old fullsize van had, or a single door that swings to the side like our 2006 CR-V. The large lift-door strikes me as the worst option if one ever needs to carry something oversize that hangs out the back and the door doesn’t fully close. Also, eventually the gas shocks in a lift-door will fail and need to be replaced, like the cap on my pickup, except the big door would be heavy to hold up. I’ll admit that I’m also biased against lift-doors because, when I was a kid, I accidentally slammed my little brother’s hand in the back door of our parents’ Aerostar.
Visibility from the drivers seat is comparable to my pickup and the CR-V. There are no unexpected blind spots and piloting the Yukon feels fairly natural to me. The factory stereo is nice, and I briefly longed for the steering wheel mounted radio station and volume controls after getting back into my own truck. However the Yukon’s HVAC controls are located down low on the center stack, and the center armrest gets in the way when trying to adjust them.
The armrest is quite long because there are three cupholders in the end of it. In addition to those three cupholders, there is also another cupholder built into the door panel, and lots more cupholders for the passengers in the rear as well. The Yukon handily beats all of our vehicles in cupholder availability.
While it’s easy to mock new vehicles for having so many cupholders, the cupholders in our own vehicles are frankly not very good. The two cupholders in my Dodge pickup pull out of the dashboard, and do not support a cup very well. More than once has my travel mug gone sailing out and into the passenger-side footwell where I couldn’t reach it. The CR-V has two cupholders for front seat occupants, placed by your inboard elbow where they are both difficult to use and making shifting the manual transmission awkward. My big old Chryslers don’t have cupholders, but drinking or eating in those cars is verboten anyhow, so it’s a moot point.
This Yukon is equipped with a V8 with cylinder deactivation, mated to a 6-speed automatic. The engine seems competent and switches seamlessly between V4 and V8 modes. The truck moves out briskly when flogged, but when you’re pushing it hard there’s sometimes a disturbing amount of preignition rattle from the engine just before it upshifts. Other than that, I found the engine disconcertingly quiet compared to my noisy Cummins, my Chryslers and even the CR-V. Most of the time, I can barely hear the engine in this truck even with the windows open. I like to hear a little exhaust rumble when there’s a V8 connected to my right foot.
Coming off idle from a stop, I never could get used to the tip-in of the (drive by wire) throttle: nothing… nothing… nothing… GO! I believe this is a common complaint among modern vehicles with electronic throttle control. Our CR-V also has electronic throttle however, and I’ve never had cause to complain about it. Perhaps it’s programmed to respond differently because the CR-V has a manual transmission; or else Honda simply did drive-by-wire better than GM.
Once underway, the electronically controlled 6-speed transmission really kills the driving experience. It’s always trying to upshift as soon as possible to get the revs down and improve fuel economy. While it is very comfortable driving on the highway, in any other driving condition the transmission is disappointing. Acceleration is glacial until you press the pedal far enough for a downshift, and there is no engine braking whatsoever when coasting.
I experimented by putting the shifter into manual mode and limiting the top gear to 5th. The notable drawback is that manual mode disables cylinder deactivation, so the engine never goes into the fuel-saving 4-cylinder operating state. And unlike some sportier GM products (and the new 8-speed in the RAM1500), the manual gear up/down buttons can’t be used to force a temporarily downshift when the shifter isn’t in manual mode. Ultimately I found that engaging tow/haul mode when driving around town was the best compromise.
I had an opportunity to drive a familiar road with many short hills, with the cruise control set at about 90km/h (55MPH). On many of the hills, the truck slowed down noticeably as it ascended, then dropped a gear and rocketed up over the crest of the hill, blasting through the speed setpoint before coasting back to the desired speed, only to repeat the cycle moments later on the next hill. It was bad enough in one section that my wife commented, “Are you doing that or is the truck doing it by itself? It’s going to make me carsick.”
There is something wrong when a V8-powered truck can’t take minor hills without better composure. They described a similar problem road-testing the Corvette in the book “All Corvettes Are Red”, which the engineers corrected through software tweaking. Wish those engineers had taken this truck for a drive too!
My average fuel mileage was 14.8L/100km (15.9 MPG-US) according to the trip computer. The reported average fuel usage was 14.7L/100km when I initially drove off the rental company lot, so I’d presume that my results are fairly typical, despite my experimentation and occasional jackrabbit starts. Most of my driving was commuting to work, which is a mix of stop-and-go with highway sections having a 50MPH speed limit.
It’s not too surprising that the suspension is tuned to give a car-like ride, given the typical use of these SUVs. It takes train tracks, potholes, rough roads and sudden steering input with aplomb closer to my big old Chryslers than the stiff ride of my pickup truck. The steering is completely numb but precise, and easy to get used to. Considering what I normally drive, I have no cause to complain about the steering at all. Being able to steer with two fingers on the wheel is a win in my books.
I didn’t get an opportunity to play with the four wheel drive system. I’m not a 4WD fanatic, and if I bought something like this for myself, I think I’d prefer if it was strictly rear wheel drive. Unfortunately, I also didn’t have cause to tow anything with the Yukon. I presume that the fuel mileage would take a significant hit, a definite advantage of my diesel pickup. My brother drove a similar truck to this and said that simply towing an empty car dolly on the highway adds enough resistance that the engine never enters cylinder deactivation mode. (He also had other choice words about the cylinder deactivation system; the reason he had the truck was to repair it.)
The Yukon had some good points and some bad points. While it was fun trying something new, I was mostly relieved to get my own truck back. There was a growing number of things on my to-do list which warranted a pickup truck. I probably wouldn’t migrate to an SUV for a future vehicle purchase, but when I eventually buy another pickup however, it will be a crew cab.
Nice review, although I’m sure you would have preferred to not get your truck damaged and just keep driving it.
I had to ride in the 3rd row of one for a work trip, it was hard to get my tall old self folded back in there with my knees at my ears.
I know that road, my 5-speed Focus takes it just fine in 4th, no shifting required 🙂
Considering the amount of hassle that the insurance company gave me, in retrospect I wouldn’t have even bothered to file the claim at all.
Our CR-V takes that road in 5th gear without any drama either. I’m not sure if the section pictured is the exact portion that caused my wife to complain, but I got tired of retracing the entire journey to my inlaws’ via Google Streetview. 🙂
The backseats in these really aren’t meant for regular use. I think a center front seat is far more versatile, but those are rare these days.
HOW can a boxy, truck based vehicle NOT have enough room behind the seats to store groceries?
WHERE does all that length/space disappear to?
I’ll tell you: BOF construction (and 4WD option) requires a high floor, & the long, macho engine compartment for the RWD V8 reduces useful longitudinal space.
I’m appalled too. Yet I think the Yukon is all that will fit in many garages.
You have to keep in mind that the third row in these, like in most all SUVs, is only meant for occasional use. If you need that third row seating on a regular basis you’d go with the Yukon XL.
We were referring only to the cargo space •behind• the seats, not the seats themselves. But since you brought it up, I don’t recall being impressed by the legroom even in the 2nd row of a Suburban because, again, of that high floor. I think (with a little uncertainty) that old full-sized station wagons were better there, maybe someone with more recent experience than mine can chime in. Of course station-wagon 3rd-seats were no comparison.
My point is that you needed cargo space and seating at the same time, you would buy a Yukon XL. If you have the 3rd row out on these there is plenty of cargo space and you still have seating for up to 6 without them.
I find the second row of Suburbans/Tahoes quite comfortable. 3rd row is cramped. But so is the 3rd row of our minivan.
BOF doesn’t equal to high floor and roof. BOF traditional sedan/coupes are longer, wider and lower than any European cars ( maybe except few Soviet ones ) even though most of them comes with unibody.
Even unibody SUVs have lousy space utilization, so you may have a point there. Why then must the floor be so high if my reason is incorrect?
Ground clearance and full size spare tire.
Full-sized spares used to fit in the rear quarter of big Country Squires et al., protected from the elements.
Not tires this size. And not with the ground clearance this has.
Nonsense. BOF construction has nothing to do with the length of the vehicle. Having a V8 up front isn’t the cause in this situation either. Take a look at the Trailblazer, it can house the same engine family under a much shorter hood.
The reason there isn’t a lot of room behind the 3rd row is because GM needed to create a significant difference between these and the Suburban to give people a reason to spend more money on the Suburban.
Nonsense. The Tahoe didn’t debut with a third-row and didn’t get one for several years. The Tahoe is preferred by those with a couple of older children, the Suburban is preferred by those with several smaller children and their seats. I know several people who would NEVER buy a Suburban (large size) but are REPEAT Tahoe buyers. So your theory fails. Sorry!
You are correct that Ford caught GM with their pants down when they put a 3rd row in the Expedition. So they cobbled one together for the Tahoe, but this generation was always available with a 3rd row.
How does my theory fail, GM doesn’t want the Suburban and Tahoe to be too close together so they can charge more for the Suburban. Yes there are those that prefer the smaller Tahoe and wouldn’t consider a Suburban and there are also those that prefer the Suburban and won’t consider a Tahoe.
I won’t be engaging any further beyond this, because you are sorely…. misguided (what you say doesn’t even make sense). Ford caught GM with their pants down when Ford put a third-row in the Expedition? HUH? GM had the Suburban for Oh…”a few years” beforehand.
Please continue on with the GM Hate-orade that runs so prevalent here. I will move on elsewhere. Thanks!
Don’t let him get to you; he gets a check from Ford every month 🙂
The Suburban is much longer, so yeah Ford caught GM with their pants down when they put a 3rd row in the much shorter Expedition. They then did the same thing when they put a 3rd row in the Explorer.
GM wanted to preserve the reason to step to the Suburban and pay more for it. So they kept the Tahoe to two rows until Ford forced their hand.
I have to agree that Ford really out-did GM to put the third row in Expedition. Sure, GM had Suburban, but that is an 18+ft long vehicle. Nothing special compared to cars of yesteryear, but a nightmare to drive and park in euro-sized towns and cities (I know you have them in US too) The Tahoe is about 16.5ft and Expedition 17, so the latter can still be used as a daily driver and fit in the standard parking spaces.
I think an even more of a pants-down moment was the 2003 redesign, which made the 3rd row seating room of the Expedition comparable to much longer Suburban, not to mention the fold-flat function.
The 3rd row of the 2014 Yukon sill looks very similar to what Ford came out with in 1997. So 3rd row seating clearly isn’t a priority for GM in the SWB BOF suvs.
Ford outdid GM? GM outsells Ford 3 to 1 with their full-sized SUVs. I have nothing against Ford (I don’t know why Ford was brought up), I simply despise the anti-GM ignorance the vast majority here spew.
Now Europe is being brought into this? Please. These mammoths are made for America where we have wide-open spaces and modern three-stall garages.
Simple reason why Ford was brought up because they have more room behind that 3rd row that is actually useable by people with legs than GM has in the Tahoe. Yes the Tahoe currently outsells the Expedition but when the Expedition was launched it sold like hotcakes. Around here it replaced the Grand Cherokee as the vehicle to be seen in dropping your kids off at soccer or school and was far and away the most seen vehicle in those situations and in the Costco parking lot in the middle to upper class areas around here. How much of that was due to the fact that it put a 3rd row in a vehicle of a more manageable length certainly is debatable. GM obviously thought that the 3rd row was of sufficient interest and had a high enough take rate at Ford that they felt compelled to offer it in the Tahoe.
However they had to be careful to preserve a spot for the longer and more expensive Suburban.
WELL, considering that this IS the length of a big sedan, WITH a third-row of seating, where exactly do you expect the plethora of rear space to be? Put a third-row of seating in a big sedan and come back to me on that one.
These are vehicles based on truck frames, dimensions and ride-heights. As such, they are compromised in terms of space efficiency. The swb Tahoe and Yokon were never designed to be genuine three-row vehicles; the third seat was added because of competitive pressure. The Tahoe/Yokon were always generally the shortest of the SUVs in their class, precisely because the lwb Suburban/Yokon XL was also available. Most of the truck-based SUV tend to be longer then the Tahoe, in order to split the difference, and have more room for the third seat. If one really wants a third seat and space behind it, the Suburban is your (GM) vehicle.
The large three-row FWD CUVs are more space efficient because they were designed from scratch to be just that; they don’t have to be compromised because they have to also use the same frame and drive train for HD trucks and 4×4 trucks and such.
These are trucks, fundamentally, and with that come certain compromises.
Take a look at the current Expedition, it’s frame from the A pillar back is specific to it and they included an IRS to help get decent 3rd row accommodations and because they initially weren’t trying to keep a larger vehicle relevant they actually included space behind that 3rd row. Of course the Excursion came along but it was aimed at a slightly different market being based on the Superduty line it was intended more for working like towing a really big trailer than for dropping the kids off. The EL of course also came along but by the time those made it to market they had already set the precedent of how much room should be in the back and probably feared that returning customers would balk if they took it away. The also had the Explorer which from 02 up was a dedicated SUV that again was designed with an IRS to accommodate a decent 3rd row. They have a similar distance between the back of the 3rd row when up and the tail gate as a Tahoe. So the Expedition had to be bigger than that. Of course the Expedition and Tahoe are wider than the Explorer.
I’m not quite sure what your point is, but the Tahoe didn’t debut with a third-row and didn’t get one for several years. So the Tahoe began with “lots of room”.
Yeah but compared to its competition the Expedition it does not have a much room whether behind the 1st, 2nd or 3rd row. The fact that GM didn’t put a 3rd row in the original Tahoe is irrelevant since it has been redesigned since then and it still does not have a 3rd row that is usable by anyone with legs.
2007 models
Legroom, 2nd row
Tahoe: 39″
Expedition: 39.1″
Cargo Capacity, all seats up:
Tahoe: 16.9 Cubic ft
Expedition: 18.6
Cargo Capacity, all seats down:
Tahoe: 108.9
Expedition: 108.3
Again, the Tahoe seats up to 6 comfortably without that third row of seats and is plenty spacious. Just like the side-facing seats in the old Panther wagons, the third row is not meant to be used on a regular basis or by adults. But it’s better to have the choice than to not in my opinion.
Solid Rear Axle- that’s where a lot of the space goes. Ford uses an independent rear suspension in the Expedition that makes for a lot more room- at least height-wise. Lengthwise I’m not sure. If you want a garageable three-row SUV with better space efficiency GMC offers the Acadia with notably better space than the swb Yukon.
GM puts the care and engineering into these that they used to put into their B-C-D body offerings, and it shows.
Two of my co-workers had this vehicle; both complained about how small they were inside. They were both gone within 2 years.
I always thought they were exaggerating. Perhaps not?
Great review. I’ve driven one of these and agree with your observations. The ride is very absorbent on rough roads but the side to side head toss in the Yukon is worse than in my Sierra. Apparently the 2015 Yukons ride quite stiffly even with Magnetic Ride. I didn’t like the small rear doors, they leave very little room to swing my feet in and out. Blame it on the solid rear axle. The transmission downshifting is typical GM, long pause then abrupt lurch.
Cruise control on certain GM cars doesn’t just behave well. My ’95 LeSabre does that all day long even on flat road around 70mph making me sort of carsick. I can’t do anything mechanically about it because the other LeSabre in the showroom felt exactly the same.
But after driving that car for a while, tricks could be learned anyway about throttle and cruise control.
As for the cruise control, my 1996 Saturn SL2 also did that very thing.
Very interesting to read. I have not driven anything by “modern” GM, so this is helpful.
2 points. First, the engine/transmission characteristics do not seem very pleasant. My Kia Sedona is seamless, and reminds me more of an old Torqueflite than the constantly gear-hunting 6 speeds I keep reading about. This truck sounds like it is starting down the road we went down in the early 80s with tall gearing that could not climb hills in overdrive (I’m thinking of YOU, 1985 Crown Victoria).
Second, The Tahoe has always been a mystery to me – It is wide, tall and cumbersome, and gets shitty gas mileage – just buy the Suburban. My sister bought a Tahoe to replace a XJ Cherokee when her 2 kids got a little older. I asked why not the Suburban. Within 2 years, the Tahoe was traded on a Suburban, after she got done grousing about the lack of cargo room.
Well the Suburban is almost 2 feet longer. That makes a big difference in garages and parking lots. It’s also about $4K more expensive. It’s nice to have choices.
Both of our current vehicles, 2009 Highlander and 2011 Mustang, have six speed automatic overdrive transmissions, and both will downshift from 6th to 4th (the Toyota will sometimes grab 3rd) when going up grades. This is more noticeable when using the cruise control than not. We just got back from a 2500 mile road trip in the Highlander and there were times I had to disengage the cruise control and just drive it “old school”. This was more noticeable in the mountains but even a slight upgrade would sometimes occasion a downshift to 4th gear, with the increase in RPM that entails. Other than that I have no complaints with the transmissions in either vehicle; the ratios seem to be well chosen for the engines and the transmissions shift positively and firmly. My brother has a late model Silverado with the six speed GM auto and, in the few times I’ve ridden in it, I did not notice any particular transmission issues.
I do prefer the behavior and feel of the 4-speed in my ’06 F-150 compared to the 6 and 8 speeds in newer trucks. However I’d take the 20+ MPG economy of the new ones every day of the week. An acceptable tradeoff IMO.
It’s amazing in retrospect how bland these look for how much “fat” is in them (meaning content not weight), and surprising that post-crisis GM didn’t take the opportunity to lean out the current generation – fewer differences between divisions and from the pickups, just for a start – although they did seem to build in more flash for the effort with the latest models.
I still hate SUVs
Yep.
The description of the truck’s powertrain behavior raises some interesting and uncomfortable questions about the relevance of big V-8 engines in the modern world. If you’re buying a big American V-8 (what, 5.3 liters in this case?) with an automatic transmission, you expect effortless torque and seamless response — not necessarily blazing performance, but no fuss. However, if the the gearing is so tall and the transmission and throttle programming so deliberately subdued that you have to drive it like the “gutless little four-bangers” V-8 lovers used to disdain, what’s the point?
I don’t expect a big truck to outrun sports cars, but if I’m living with this kind of fuel consumption, I’d certainly expect to be able to be able to climb grades without having the engine screaming along in third gear like an old-school econobox or having to second-guess the transmission.
I think the engine is simply too small, big as 5.3l may be compared to your average one in a half ton sedan’s I4 or even V6, it’s not exactly big in a 6000lb brick. That kind of power to weight ratio on top of a poorly geared transmission/bad programming wouldn’t be particularly effortless and seamless on even the best most modern 4 cylinder sedans.
That explains why they put an InTech V8 in Navigator to replace the regular Modular V8. For a Mustang Cobra/Mark VIII, 4.6 version of InTech V8 was fast enough but a bigger one on a Navigator is just capable for such a big truck.
5.3 too small? This will do 0-60 in about 8.5 seconds. They are not underpowered. The gearing is simply a product of trying to gain economy, and trucks are hardly the only vehicles that suffer from excessive shifting these days.
Wide open throttle speed doesn’t equate an effortlessly livable engine, even back in the Muscle car days performance engines of less than 350 cubes could be dogs in a heavier car, the 5.3 is no different, it’s got impressive peak power because it’s making that power at an impressive(for a pushrod V8) RPM. Pretty much all other engines, whether I4, V6, V8, now a days are the same, which gives them favorable volumetric efficiency to impress reviewers and get slightly better mileage at steady state cruising, but in non WOT situations, like driving down a hilly highway with cruise on, the low end suffers and you need a bazillion speed transmission to constantly compensate for it.
I disagree. My F-150 with the 5.4 and 4 speed is of about the same power and weight as this. It does not hunt for gears or shift excessively. It pulls a 6,000 pound trailer with little effort.
That hunting in the Yukon is a product of the ratios in the 6 speed transmission and the electronics behind it. It is NOT a shortage of power or torque. And as mentioned by the author, the main issue here to begin with would seem to be the rather the poor performance of the cruise control.
I wasn’t implying that the engine was short of muscle, because it’s obviously not. My point is that if a big (and 5.3 liters is big in modern terms) V-8 basically has to be fed the electronic equivalent of horse tranquilizers to keep its official-cycle fuel consumption and emission under control and still only returns 15 mpg in the real world, it no longer makes much sense. At that point, why not just buy a smaller engine (perhaps with forced induction) that could at least be geared and programmed less stingily? Even if it wasn’t any quicker in absolute terms and returned no better real-world economy, it’d be nice to not feel like the powertrain is narcoleptic.
It used to be that big, normally aspirated engines had some clear real-world advantages over smaller, more high-strung and/or boosted engines, but I’m not so sure that’s realistically true anymore.
(And yes, I’m well aware that this is by no means the only many-speed automatic that’s programmed for the EPA or ECE cycles rather than real-world drivability, but even so — why buy a V-8 if the vehicle is programmed to never really let you use it?)
These engines have plenty of power for these vehicles. Modern cars and trucks are all optimised for fuel economy. They go for the lowest gear as soon as they can, and if the transmission doesn’t kick down quickly enough, they can seem like slugs. Modern GDI technology gives great efficiency as they allow stratified charge and reduced pumping losses, as well as better ping resistance.
Bazillion speed (and CVT) transmissions are not going away.
Ate Up With Motor: Well that’s been Ford’s approach with the 3.5 and now the new 2.7 twin turbos. I really like that 2.7, it offers better performance than my 5.4 and returns minivan mileage. I don’t know if they are any more tractable though. And only time will tell how reliable such a small twin turbo direct injected engine will be in the long run.
> If you’re buying a big American V-8 (what, 5.3 liters in this case?) with an automatic transmission, you expect effortless torque and seamless response — not necessarily blazing performance, but no fuss. However, if the the gearing is so tall and the transmission and throttle programming so deliberately subdued that you have to drive it like the “gutless little four-bangers” V-8 lovers used to disdain, what’s the point?
My thoughts exactly. I suspect that it’s tweaked to perform well on fuel economy testing, but the real-world driving experience suffers.
Part of the problem on hills / using the speed control could be how far the speed is allowed to fall from the setpoint before the computer decides to take action. Even if it had downshifted from 6th to 5th sooner, the transition wouldn’t have been so jarring. Isn’t that the point of modern transmissions with more gears, to keep the engine in its ideal torque band?
Alternatively, if the computer was programmed to recognize that this happened once and now was slowing down again on the next hill, it could recognize “We are probably driving over a series of short hills now, I’ll change the way I shift to accommodate.” so the nauseating behaviour didn’t happen repeatedly. I’m sure that the ECM in this truck is capable of implementing such an algorithm.
A big part of the problem is the cruise control programming. When the cruise commands a down shift it is usually way late and is then held for much longer than absolutely necessary. Turn off the cruise in the hilly area give it a little gas before you start up the hill and let it gain a little speed on the way down and you usually won’t end up with the downshift and you’ll get much better mpg overall.
i really hate this kind of “new normality” which is why i am generally put off by European and Japanese cars (even though i live in Europe). That you buy a new or relatively newish car and then actually find out that due to all the fuel saving features it drives worse than your old car and it is impossible to get it to drive normally (i.e like a V8 mated to a 4-speed circa 1990s). With the Yukon there is at least the option of engine and transmission calibration (either factory or aftermarket)
It is lucky that tow/haul mode makes it somewhat drivable. My mother once had a top of the line gasoline Citroen with an automatic, which had a sport-mode for the transaxle. It didn’t make it faster, though. It just made it sound worse.