Introduction

The GMC Yukon is a full-size SUV, built on a truck chassis, ready to tow heavy trailers, haul large amounts of cargo and/or small busloads of people. And it can withstand the abuse of rough, unpaved roads on a regular basis, something car-based crossovers cannot endure. 

Except for addition of tire-fill alert to the tire-pressure monitor, standard Yukon and Yukon XL models have not changed significantly for 2018. 

Close kin to the Chevrolet Tahoe and Suburban and Cadillac Escalade, Yukon is a big, wholly traditional SUV, though thoroughly modernized. Equipped with a muscular V8, the Yukon unreels sufficient power to perform energetically on the highway, or tow a trailer with ease. 

For 2018, Yukon Denali, the top GMC trim level, adopts a sophisticated 10-speed automatic transmission. Denali appearance has been revised for 2018, but the differences are modest. 

Yukon XL is 20.5 inches longer overall than Yukon, on a wheelbase that's 14 inches longer. Yukon XL offers much more third-row legroom than does the Yukon, making Yukon XL better for large numbers of passengers. The added length of the wheelbase, 116 inches for Yukon, 130 inches for Yukon XL, makes the XL a more stable platform for trailer towing. Yukon is the same length as the Chevy Tahoe, while the Yukon XL is the same length as the Suburban. 

Unlike car-based crossover SUVs, Yukons are built using a separate body and frame and a solid rear axle. While crossovers can transport passengers more efficiently, the Yukon models are more capable of pulling trailers. 

A Yukon can be equipped to tow as much as 8,500 pounds. 

GMC Yukon and Yukon XL come in SLE, SLT, and Denali trim levels, with rear-drive or four-wheel drive. Yukon Denali versions are almost as luxurious as Cadillac Escalade, which echoes the Yukon's construction. Chevrolet has no Denali equivalent. 

In Yukon SLE and SLT, a 5.3-liter V8 develops 355 horsepower and 383 pound-feet of torque, driving a 6-speed automatic transmission. 

Only the Yukon Denali gets GMC's 6.2-liter V8, sending 420 horsepower and 460 pound-feet to the new 10-speed automatic. 

Like its Chevrolet counterparts, Yukon is the last SUV to offer the option of a three-place front bench seat, replacing the standard front buckets. The second row is less spacious. In a standard-wheelbase Yukon, the third row is surprisingly tight, but a Yukon XL third row is friendlier to adults, with 10 inches of additional legroom. 

Yukons with front buckets include a special airbag meant to keep occupants apart during a collision. Several forms of collision-avoidance technology are available, including adaptive cruise control and automatic braking, as well as blind-spot monitoring and lane-departure warning. Low-speed automatic braking is optional for Yukon SLE, but standard on SLT and Denali. Full-speed emergency braking and adaptive cruise control are SLT/Denali options. 

Crash-testing by the National Highway Traffic Safety Administration gave the standard-length 2018 Yukon four stars overall, but five stars in frontal and side impacts, and three stars for rollover protection (a calculated figure). That's no surprise for a top-heavy SUV. The Yukon XL earned only a four-star score for frontal impact. 

Lineup

Yukon XL adds $3,000 to price of any Yukon model. 

Yukon SLE ($49,080) comes with the 5.3-liter V8, rear-wheel drive, cloth upholstery, front bucket or bench seats, three-row seating, automatic three-zone climate control, 18-inch wheels. Four-wheel drive is available ($52,080). Yukon XL costs $3,000 more. (Prices are MSRP and do not include $1,295 destination charge.) An Enhanced Driver Alert package adds automatic emergency braking, forward collision warning, and active lane control. 

Yukon SLT ($57,130), available with four-wheel drive ($60,130), adds perforated leather upholstery, heated front and second-row seats, ventilated front seats, a heated steering wheel, pushbutton start, and power-folding seats. 

Yukon Denali ($66,165), available with four-wheel drive ($69,165) includes the 6.2-liter V8 and 10-speed automatic, along with 20-inch alloy wheels and a magnetically controlled suspension. A new Ultimate Package adds power-retractable side steps, 22-inch wheels, and adaptive cruise control. 

Walkaround

Still unabashedly boxy-shaped like its predecessors, the Yukon boasts chiseled styling, highlighted by cleanly conservative body lines. Cutting down on curves, GMC manages to give the Yukon a sense of flair, without making it seem trucklike. 

SLE and SLT trim levels differ little visually. Swept-back headlights complement the boxy grille. Large LED taillights dominate the simple, squared-off rear end. 

Every Yukon conveys a look that suggests a comparatively high-end vehicle. For better or worse, the GMC Denali is ladled with an abundance of chrome. 

Interior

Yukon cabins are handsome and luxurious. Regular-length Yukons aren't as spacious as might be expected. 

Deliciously curvaceous and carlike, the symmetrical dashboard looks like it might belong inside a luxury-level sedan. An 8.0-inch touchscreen sits high, above logically laid-out controls that convey a hint of truckiness. Easy and quick to use, the infotainment system includes Apple CarPlay and Android Auto connectivity. 

SLT and Denali editions feature impressively-grained leather upholstery. Soft-touch materials abound, even in SLE trim. 

All seats are comfortable. While the second row gives two passengers some elbow room, it's wide enough to accept a third rider, at least for shorter trips. In standard-wheelbase Yukons, the third row is best for youngsters. In contrast, the XL provides ample stretch-out space as well as 39.3 cubic feet of cargo room. With its third row upright, cargo volume is only 15.3 cubic feet in the regular-size Yukon. 

Relatively high liftover can make cargo-loading a bit of a chore. Folding second- and third- row seatbacks expand cargo space to almost 95 cubic feet in the standard Yukon, versus 121 cubic feet in XL models. 

Driving Impression

Both engines promise strong performance, even when towing. Acceleration is well beyond adequate with the standard 5.3-liter V8, while the Denali's 6.2-liter V8 delivers remarkably eye-opening response to the gas pedal. Considering that a Denali weighs about 5,500 pounds, that's quite an achievement. 

SLE and SLT versions provide the most comfortable ride, due in part to their high-sidewall tires. Even with its bigger wheels, the Denali also satisfies in ride comfort. 

The Yukon's weight is most noticeable on curvy roads, especially in Denali trim. Fortunately, steering is direct and accurate, and the body doesn't lean too much when cornering. Magnetically-controlled shock absorbers in the Denali help counteract the effect of its bigger wheels. Smaller bumps are absorbed effectively, for a luxurious feel, but the suspension firms up when needed. 

Sound emanating from the standard V8 is muted and refined. Both engines can run on half their cylinders in light-load usage, to help reduce fuel consumption. 

No Yukon functions as a serious off-road vehicle, but optional four-wheel drive includes a low range that helps maintain traction on unpaved roads and trails. 

For such sizable SUVs, fuel economy is reasonably good with the 5.3-liter engine, if more troubling with the Denali. Rear-wheel-drive regular Yukons are EPA-rated at 16/23 mpg City/Highway, or 19 mpg Combined. Four-wheel drive lowers those figures to 16/22/18 mpg. 

With rear-drive, the Yukon Denali's 6.2-liter V8 is EPA-rated at 14/23 mpg City/Highway, or 17 mpg Combined. Four-wheel-drive, short-wheelbase Denalis are EPA-rated 14/22 mpg City/Highway, or 17 mpg Combined; but 14/21/16 mpg for the Yukon XL Denali. 

Summary

Denalis are the top sellers, despite their startling prices. Every Yukon is well-equipped, while the Denali approaches luxury grade. For most families, a crossover might make more sense; but many drivers still favor the feel of a big, rear-drive, traditional SUV. 

Driving impressions by Andrew Ganz, The Car Connection. James M. Flammang contributed to this report.