2021 GMC Yukon AT4 Off-Road Driving and Towing: Long-Term Report 3

gmc yukon Full Overview

It is always good when we get to this point in the life cycle of a long-term test vehicle and have nothing of major importance to report. Such is the case with our award-winning 2021 quad bike 2021 GMC Yukon AT4. After 9 months of traveling and more than 16,000 miles, the Yukon is still rock hard, and we are as fond of the vehicle today as we were the day it was left.

During the first half of the year, we spent a lot of time with a trailer on a trailer. With 355 hp and 383 lb-ft of torque from the 5.3-liter V-8 engine and a respectable 8,200-pound towing capacity, the Yukon AT4 has proven to be a competent towing rig. One area that we are not so sure about is the adjustable air suspension when towing. The system has a number of positive features, the most useful being automatic load balancing and the ability to raise and lower the vehicle’s height when coupling. At the back there are several small bugs that we have encountered that we feel need to be addressed.

The same automatic load balancing capability that we enjoy on the road has on many occasions made it difficult to disconnect, especially when the trailer is not level with the vehicle, as it will continue to adjust even when the vehicle is off. We also have the setting activated which automatically lowers the vehicle down to the lowest entry level when it is placed in the Park. This is fine, except when trying to couple a trailer. We wish there was an easy way to lock the air suspension when towing, as it would be very helpful to have full control of the suspension without the vehicle doing anything automatically. In addition, we received a strange error message when we towed side by side on our trailer. The full load was about 5,000 pounds with about 500 pounds heavy, well within the Yukon’s limits. Upon arrival in the desert and disconnected from the trailer, the vehicle flashed “Height adjustment not available, air suspension overloaded.” It took several miles of driving and key cycles to get this done and allow us to encounter the higher off-road suspension settings. We had not seen this before, and have not since, so we will be looking for it in the last quarter.

Speaking of the 2021 GMC Yukon AT4’s air suspension, we drove some incredible off-road tracks this quarter and had a chance to use all of the vehicle’s off-road hardware. With the Yukon’s transfer case moved to the low range, we were able to raise it to the highest suspension setting, giving an impressive 34.5-degree approach angle, 22-degree angle of refraction and 10-inch ground clearance. We waded through two feet of water, drove through soft sand, climbed up steep hills, crossed rocky riverbeds and blasted down graded roads. About the only thing we did not do was hardcore rock crawling … for obvious reasons.

We still appreciate the Yukon AT4’s electronic rear limited-slip differential, which works quite well when traction begins to wane. Selecting the “terrain” driving mode (Yukon AT4 has Normal, Towing / Off, Off-Road and Sport driving modes) improves gas mapping and gearbox shifting when tough. And the Yukon AT4’s standard ground control is really useful for those who choose to use it. Like most air suspension-equipped off-road vehicles, we have noticed that the Yukon AT4’s ride quality deteriorates significantly the higher it is raised (it is still better than most, however, thanks to the active ride control dampers). Although the extra 2 inches of ground clearance is good when driving over large obstacles, we have found that the normal ride height is the most comfortable for most general terrain scenarios. Unfortunately, it looks like we are going another year without the opportunity for snow or mud on the west coast. While we’re confident in the Yukon’s snow ability, we would do our best to avoid deep mud holes, but it’s more of a personal preference nonetheless.

What’s hot, what’s not

  • Warm: Wonderful styling continues to attract attention, 5.3-liter V-8 engine is very powerful, all seven seats are comfortable for adults
  • Not: Panoramic sunroof is good for looking at the car wash brushes and not much more, fuel economy is still on the low side, wireless Apple CarPlay has become a bit buggy

When you move back inside, the interior continues to prove to be a comfortable fortress of solitude for the most part. If we were to specify the Yukon AT4 again, we can say that we would now find a way not to have the panoramic sunroof. Personal preferences play a big role in this; However, we have discovered that the glass roof and fabric cover let in a lot of heat and noise. Unfortunately, the sunroof is grouped together with the AT4 Premium Plus package, so it would require some smart options to get the features we love without the glass roof. Another polarizing feature we love is the head-up display. We leave it on speed for the most part, but it has the ability to display terrain data, stereo information and navigation. It has become such a useful tool that we do not know how to live without it when the Yukon is gone.

We have put adults in all three rows of GMC Yukon AT4 and have not had a single complaint. The captain’s chairs in the middle row both tilt and slide, while the third row now has much improved legroom thanks to the Yukon’s new independent rear suspension. There are even USB-C charging options for everyone except the rear center passenger, which is quite impressive.

As we enter the final quarter of evaluation, we are unhappy with the proposal to return the 2021 GMC Yukon AT4 to its rightful owner. After just completing the second scheduled service at 15,000 miles, we do not anticipate a new dealer visit. So all that remains for us to do is to enjoy our remaining months with the big SUV. We stick to the plan that has worked so far, we have more off-road driving, towing and road trips on the books. Here we hope for another hassle-free quarter when we send off the Yukon AT4 in style.

Price: 2021 GMC Yukon AT4

Long-term number

Miles since last report: 4,718

Average mpg (this report): 13.58

Test best tank (mpg): 18.78

Test worst tank (mpg): 9.28 (pull 8,000 pounds)


This period: oil change, tire rotation, air filter, fluid replenishment (15,000 miles), spare camera recall

Logbook quotes

  • “I’m really glad the Yukon has a small gas tank now, because it takes two short sweeps if I let it go under a quarter of a tank … yikes.”
  • “FINALLY we have found a good use for the sliding center console! It perfectly holds the giant bathtub with cheese puffs for snacks on the road trip!”
  • “Compliments continue to pour in for the Yukon AT4, from the old man at the gas station to the parents at Disneyland and everywhere in between.”
  • “Just went through a deep water crossing in our AT4 factory while laughing at all the equipped jeeps that followed.”

Options tested

  • AT4 Premium Package ($ 9,145)
  • Cayenne Red Tintcoat Color ($ 645)
  • Second Row Heated Buckets ($ 370)
  • Power Sliding Center Console ($ 350)

More information: 2021 GMC Yukon AT4

Backcountry exploration is really what the GMC Yukon AT4 is best suited for. Getting out and finding abandoned mines and ancient relics from previous centuries is one of our favorite pastimes, and the Yukon AT4 is one of the most comfortable and capable SUVs for the activity.

We would still love it if GMC could find a way to package the amazing 3.0-liter Duramax diesel I-6 engine from Yukon Denali in AT4. Allegedly, the AT4’s front ski plate interferes with the diesel engine’s charge air cooler. Still, the prospect of 460 lb-ft of torque with 26 mpg on the highway is quite enticing.

The combination of our Yukon AT4’s Cayenne Red paint, dark chrome, front ski plate and off-road tires gives the vehicle a rather sinister look. And it has attracted attention everywhere we go. People simply love the Yukon AT4.

This little block here, at the front of the center console, contains the SUV’s cordless phone charging pad. Just drop your device on the tablet and it will start charging automatically. The problem is that our standard size iPhone is not large enough to stay centered and would often lose charge just by sliding to one side or the other. Needless to say, this place now only collects rubbish.

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