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

gmc yukon Full Overview

It’s always good when we get to this point in the life cycle of a long-term test vehicle and have nothing serious to report. Such is the case with our award-winning 2021 GMC Yukon AT4 2021 ATV. After 9 months on the road and more than 16,000 miles, the Yukon is still rock solid, and we’re just as enamored with the vehicle today as we were the day it was left.

During the first six months we spent a lot of time with a trailer in tow. With 355 hp and 383 lb-ft of torque from the 5.3-liter V-8 engine and a respectable towing capacity of 8,200 pounds, the Yukon AT4 proves to be a capable towing rig. The one area we’re not so sure about is the adjustable air suspension when towing. The system has a number of positive features, the most useful of which is automatic load balancing and the ability to raise and lower the height of the vehicle when connected. On the flip side, there are several small quibbles we’ve encountered that we feel we need to address.

The same automatic load leveling capabilities that we enjoy on the road have 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 turned off. We also have the setting activated that automatically lowers the vehicle to the lowest entry level when placed in Park. This is fine, except when trying to hitch 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. Also, we got a strange error message when towing a side by side on our utility trailer. The full load was about 5,000 pounds with about 500 pounds of curb weight, well within the Yukon’s limits. Upon arrival in the desert and disconnected from the trailer, the vehicle flashed “Height adjustment unavailable, air suspension overloaded.” It took several miles of driving and key cycles to get this to work and allow us to bump into the higher off-road suspension settings. We hadn’t seen this before, and haven’t since, so we’ll keep an eye out for it in the final 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, yielding an impressive 34.5-degree approach angle, 22-degree break angle and 10 inches of ground clearance. We waded through two feet of water, drove through soft sand, climbed steep hills, crossed rock-strewn riverbeds and blasted down graded roads. About the only thing we didn’t 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 starts to wane. Selecting the “off-road” drive mode (the Yukon AT4 has Normal, Tow/Tow, Off-Road, and Sport drive modes) improves throttle mapping and transmission shifting when the going gets rough. And the Yukon AT4’s standard hill control is certainly useful for those who choose to use it. Like most off-road vehicles equipped with air suspension, we’ve noticed that the Yukon AT4’s ride quality degrades significantly the higher it’s raised (it’s still better than most, though, thanks to the active ride control dampers). While the extra 2 inches of ground clearance is nice when driving over large obstacles, we’ve found the normal ride height to be the most comfortable for most general off-road scenarios. Unfortunately, it looks like we’re going another year with no chance of snow or mud on the west coast. While we’re confident in the Yukon’s snow capabilities, we’d do our best to avoid deep mud holes, but that’s more of a personal preference anyway.

What’s hot, what’s not

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

Moving back inside, the interior continues to prove a comfortable fortress of solitude for the most part. If we were to spec the Yukon AT4 again, we can say that we would now find a way to not have the panoramic sunroof. Personal preference plays a big part 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 bundled with the AT4 Premium Plus package, so it would take some clever 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 most of the time, but it has the ability to display terrain data, stereo information and navigation. It has become such a useful tool that we don’t know how we will live without it when the Yukon is gone.

We’ve stuffed adults into all three rows of the GMC Yukon AT4 and haven’t had a single complaint. The middle-row captain’s chairs both recline and slide, while the third row now has much-improved legroom thanks to the Yukon’s new independent rear suspension. There’s also USB-C charging capabilities for all but the rear center passenger, which is pretty impressive.

As we enter the final quarter of the evaluation, we are unhappy with the proposal to return the 2021 GMC Yukon AT4 to its rightful owner. Having just completed the second scheduled service at 15,000 miles, we don’t foresee another dealer visit. So, all that’s left for us to do is enjoy our remaining months with the big SUV. In keeping with the plan that has worked so far, we have more off-roading, towing and road trips on the books. Here’s hoping for another trouble-free quarter as we send the Yukon AT4 off 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 (towing 8,000 pounds)


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

Quote about log book

  • “I’m really glad the Yukon has a small gas tank now, because it takes two short swipes if I let it go under a quarter tank… yikes.”
  • “FINALLY we found a good use for the sliding center console! It perfectly accommodates the giant tub of cheese puffs for road trip snacks!”
  • “The compliments keep pouring in for the Yukon AT4, from the old man at the gas pump to the parents at Disneyland and everywhere in between.”
  • “Just went through a deep water crossing in our factory AT4 while laughing at all the equipped Jeeps that followed.”

Alternative as tested

  • AT4 Premium Package ($9,145)
  • Cayenne Red Tintcoat paint ($645)
  • Second-row heated buckets ($370)
  • Power Sliding Center Console ($350)

More information: 2021 GMC Yukon AT4

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

We’d still love it if GMC could find a way to pack the awesome 3.0-liter Duramax diesel I-6 engine from the Yukon Denali into the AT4. It is claimed that the AT4’s front skid plate interferes with the diesel engine’s intercooler. Still, the prospect of 460 lb-ft of torque with 26 mpg on the highway is pretty enticing.

The combination of our Yukon AT4’s Cayenne Red paint, dark chrome, front skid plate and all-terrain tires gives the vehicle a pretty wicked look. And it has attracted attention everywhere we go. People simply love the Yukon AT4.

This little nub here, at the front of the center console, houses the SUV’s wireless phone charging pad. Just drop your device on the pad and it will start charging automatically. The problem is that our standard size iPhone isn’t big enough to stay centered and would often lose charge just by sliding to one side or the other. Needless to say, this place now just collects trash.

Looks good! More details?

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