With the debut of the 2021 Yukon AT4, GMC now offers the AT4 sub-brand across its entire model lineup.  -  By Mike Antich

With the debut of the 2021 Yukon AT4, GMC now offers the AT4 sub-brand across its entire model lineup.

By Mike Antich

When GMC revealed the fifth-generation 2021 Yukon and Yukon XL, it also revealed the first-ever Yukon AT4 model, designed to be an off-road capable vehicle with a premium interior offering three-row seating that can comfortably accommodate a six- to eight-person work crew and their equipment.

With the debut of the 2021 Yukon AT4, GMC now offers the AT4 sub-brand across its entire model lineup. GMC’s first AT4 model was the Sierra AT4 pickup and more recently, the Sierra HD AT4, and Acadia AT4.  

All AT4 models include four-wheel drive as standard equipment, with a two-speed transfer case that includes low-range four-wheel-drive gearing when off-road driving conditions turn tough. 

Off-Pavement Work Applications

During off-pavement work operations, the available four-corner air ride adaptive suspension can be raised to offer an additional two inches of ground clearance, which creates a total ride-height adjustment of up to four inches. During higher speed highway driving, the system automatically lowers Yukon’s ride height three-fourths of an inch to improve aerodynamics and fuel efficiency. There is also an automatic self-leveling feature when the vehicle is loaded with cargo or when trailering.

For descending steep off-road grades, Yukon AT4 has Hill Descent Control. This uses the anti-lock braking technology to assist with a controlled descent on uneven terrain by eliminating the need to ride the brake pedal.

Another nice feature of the Yukon AT4 is the magnetic ride control, a technology pioneered on sports cars, that enables precise body control and handling capability. It is a fast-reacting damping system that uses sensors to continually read the road and alter the damping rate of the shocks. It reacts much faster than traditional shock absorbers to reduce bouncing, body roll, and vibrations.

A nice safety technology is the available electronic Limited Slip Differential (eLSD), which preemptively manages axle torque. If wheel slip is detected on either side, the eLSD shifts power to the wheel with better traction.

The Yukon AT4 is powered by GM’s 5.3L EcoTec V-8, which generates 355 horsepower and 383 lb.-ft. of torque. The engine is paired to a new-for-2021 10-speed automatic transmission offering smooth power delivery in a variety of driving situations. The 5.3L engine also features stop/start technology and new Dynamic Fuel Management that enables the engine to operate on two to eight cylinders, depending on demand, to optimize power and fuel efficiency.

In a work setting requiring frequent vehicle ingress and egress, getting in and out of the front or rear seats is easy thanks to the power deployable side steps. Also, a driver-selectable setting lowers the vehicle two-inches to aid passenger entry and exit when parked. When hauling work crews, entering or exiting the third row is easier as the middle seats can tilt forward. 

A big change for 2021 is the switch to an independent rear suspension. This provides a better ride quality, more interior cargo space, and better handling dynamics. Because of the switch to an independent rear suspension, GMC has also been able to improve third-row legroom by 41%  and provide greater headroom. 

With a 4.9-inch-longer wheelbase and 6.1 -inch increase in overall length compared to the prior model, the Yukon offers 66% greater cargo volume behind the third row, amounting to 25.5 cu.-ft. With the second row seat folded flat, there is a total of 72.6 cu.-ft. of cargo volume and 122.9 cu.-ft. with both the third and second row seats folded flat.

About the author
Mike Antich

Mike Antich

Former Editor and Associate Publisher

Mike Antich covered fleet management and remarketing for more than 20 years and was inducted into the Fleet Hall of Fame in 2010 and the Global Fleet of Hal in 2022. He also won the Industry Icon Award, presented jointly by the IARA and NAAA industry associations.

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