Video: 2021 GMC Yukon AT4 First Off-road Review! SUV vs Truck!

They take on Tombstone Hill !

2021 gmc yukon at4 off-road trail review silverado chevy

How does the all-new 2021 GMC Yukon AT4 stack against the most off-road capable Chevy pickup truck – the Silverado Trail Boss? You might be surprised to find out!

2021 GMC Yukon AT4

The Yukon is all-new for this year. The AT4 off-road model is a first-ever for the Yukon lineup. The new Yukon AT4 is a close relative to the new 2021 Chevy Tahoe Z71. This AT4 has nearly every available option. It includes the dynamic and height-adjustable air suspension, skid plates, all-terrain tires, and an electronically-controlled Limited Slip Differential (aka. eLSD or Active Response 4WD) in the back. Final manufacturer suggested price for this Yukon AT4 stands at $77,055.

This premium SUV has four-corner air springs. The driver can select between four distinct ride heights: entry/exit, normal, off-road 1, and off-road 2. The highest off-road 2 height is only available in 4LO transfer case setting. It’s meant for slow-speed off-road driving. The SUV is equipped with Magnetic Ride Shocks that are dynamically adjustable to terrain, speed, and driving style.

Under the hood is a 5.3-liter V8 (355 hp and 383 lb-ft of torque) engine that is mated to a 10-speed automatic transmission. Currently, a 6.2-liter V8 is not available in the Yukon AT4 off-road models.

Chevy Silverado 1500 Trail Boss

2021 chevy silverado 1500 trail boss yukon at4 review off-road

The truck is our long-term Chevy Silverado 1500 Trail Boss. It has the same 5.3-liter V8 engine and the 10-speed automatic like the Yukon, but similarities end quickly after that.

While the Yukon and Tahoe are based on the new T1 pickup truck chassis – the big SUVs have a modified frame in order to accommodate an independent rear suspension. The Silverado still has a solid rear axle. The Yukon’s wheelbase that is shorter than that of the short-bed Silverado crew cab. The Yukon weighs significantly more than the pickup truck. The Trail Boss weighs around 5,500 lbs with the RoofNest tent and ThuLe rack in the back. The fully optioned Yukon AT4 weighs about 6,000 lbs.

The Trail Boss has a mechanically locking limited slip differential (aka. G80 or “mLSD“). The differential locks automatically based on wheel slip. There are no switches to push or knobs to pull.

Which Is Better? eLSD vs mLSD

Which design will work better to go up the mountain? Nathan and I first drove the Trail Boss and the AT4 up the trail in 2WD. The Silverado’s mLSD did the job, it locked up – the lack of weight in the rear prevented the Trail Boss from finding grip on loose dirt. The Yukon AT4 went up the entire trail in 2WD with the rear eLSD working seamlessly and quickly. This very impressive.

Next, we switched both truck into 4-Lo and went up the trail again. Trail Boss and the Yukon made it up without much trouble. However, the G80 mLSD in the Silverado often needs one wheel to spin several revolutions in order to lock. This can make for a jerky movement once in a while. The eLSD and the extra weight in the rear made the Yukon AT4 silky smooth and very capable during our test.