Naturally, we wouldn't be this complimentary had complaints not remained few and far between. Our biggest gripe was one that persisted from start to finish and involved the odd combination of a relatively small fuel tank and less-than-desirable fuel economy. While the 2021 GMC Yukon AT4 came with an EPA rating of 15 city, 20 highway, and 17 combined, we never really got there. Throughout the year, we managed between 13.5 and 14.5 mpg in combined driving, and it wasn't until our final week with the Yukon that we broke the 20-mpg barrier on the highway. And for those wondering, we don't drive fast or aggressively, so there's not much room left for improvement. When combined with the small-for-its-size 24-gallon fuel tank, we found ourselves filling up about every four days during the busy driving season. Even worse, when towing at full capacity we would need to stop for fuel about every 150 miles.

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Because we managed to log more than 7,000 miles since our third long-term report, we were due for another oil change at the 22,500-mile mark. In taking the Yukon to our local GMC dealer we had an unusual encounter that's worth noting. Upon seeing the license plate on the Yukon and noting that it's a GM-owned vehicle, our service technician (not knowing we were watching) increased the price of the oil change manually. This certainly left us with a dirty feeling, especially after waiting nearly two hours for a simple oil change.

On the flipside, we also had our first flat tire of the year two weeks prior to the Yukon's retirement. As always happens, late at night in the bad part of town, we had the TPMS warning light illuminate. Thankfully the rate of pressure decline was slow enough that we made it safely off the freeway. Taking the vehicle to the local America's Tire (known as Discount Tire in most of the country), we had the flat fixed. The company always fixes flats for free, so after getting a plug and having them show us the tiny screw that was removed, we were on our way. Sadly, we walked out to the Yukon the next morning only to find the tire flat again. Another trip to America's Tire revealed a much larger gash in the middle of the tread. Apologetic for missing the issue the day before, the crew at America's Tire had a fresh Goodyear tire rushed in the next day, installed it quickly, and had us back on our way in no time. In contrast to our experience at the GMC dealer, the America's Tire crew was top-notch and went above and beyond to make sure we were taken care of and satisfied.

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During this final quarter, we set out on a 2,500-mile road trip with the Yukon through California, Arizona, Utah, and Nevada, towing our 21-foot toy hauler trailer. As we've noted in previous reports, this trailer is right at the maximum of what the Yukon AT4 is rated to tow. Despite this, we found the Yukon to be an exceptional tow vehicle. Even with the smaller 5.3-liter V-8 engine we never had issues with large grades or sustained wind. Our only issue came while traversing the salt flats west of Salt Lake City, Utah, in a windstorm. We, along with everyone else on the road, were forced down to about 40 mph while contending with broadside gusts of more than 50 mph. That was a bit of a white-knuckle experience that wouldn't have been as harrowing with either a smaller trailer or larger tow vehicle. Even still, the Yukon plowed ahead with relative ease. Really, the only pitfall of towing 8,000 pounds with the Yukon through such varied terrain was the 8.46-mpg average fuel economy.

We also made sure to get out and log more dirt miles under the Yukon's Goodyear Wrangler TrailRunner AT tires. We managed to wheel on a pretty diverse mix of terrain, with everything from sandy beaches to mountain trails, forest roads, massive sand dunes, desert washes, and even the Bonneville Salt Flats. The Yukon AT4 continued to amaze us with its off-road ability right up to the very end. Entering off-road mode ensured that the adaptive air suspension remained in its higher off-road setting as well as adjusting the transmission shift points and throttle mapping for better response. In each of these situations the Yukon performed admirably, got through any obstacle with ease, and took us deeper into the backcountry than a three-row family SUV ought to be able to.

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All things considered, we definitely shed a tear or two when the Yukon AT4 was taken home. Small quibbles aside, we had no real issues and we had gotten used to receiving compliments everywhere we went. We found the 2021 GMC Yukon AT4 to be incredibly well-rounded, good at just about everything, and comfortable in every situation, both on- and off-road. It was indeed one of the best.

Report: 4 of 4

Previous reports: February 2022, May 2022, August 2022
Base price: $64,800
Price as tested: $75,605