With two body styles, three trim levels, and three basic engine variants, the Yukon's performance envelope could be unmanageable-but all versions have good acceleration and ride quality, light steering, little if any handling feedback (they're huge trucks, after all), and pretty dismal fuel economy.
Standard-issue 2010 GMC Yukons offer a standard 5.3-liter V-8 with 320 hp in the shorter Yukon and 310 hp in the longer Yukon XL. Both of the smaller V-8s have plenty of torque to move the Yukon with authority, even with a full load, and fuel economy is quite respectable for such a huge vehicle, with ratings of 14/20 mpg from the EPA. Jalopnik reports the "Vortec V8 gives you a much power as you need, whenever you need it." ConsumerGuide agrees: "Yukons are muscular off the line and in highway passing/merging with the 5.3-liter V8." A special Yukon XFE edition has the same power output as the smaller base SUV, but with a taller transmission final-drive ratio for better fuel economy, at 15/21 mpg.
The Yukon XL and both Denali editions offer a 403-hp, 6.2-liter V-8, as an option on the XL and standard on either the Yukon Denali or the Denali XL. It's the pick for the toughest towing demands and accelerates smartly with a rich engine note, but mileage will only reach 12/19 mpg at most, even with new cylinder-deactivation technology applied. There's plenty of reserve power for hills, quick passing maneuvers, and full loads. ConsumerGuide doesn't think it's so different from the rest of the Yukon engine lineup; it says the "Denali's 6.2 feels only slightly stronger" than the other powerplants.
A single six-speed automatic transmission is offered across the Yukon lineup, one with "shift lever buttons for manual operation," ConsumerGuide points out. In all applications, the six-speed automatic shifts smoothly but responsively. Kelley Blue Book says its "responses are less harsh than in [previous] models, with less-noticeable delays." ConsumerGuide reports the transmission provides "crisp, timely shifts."
All Yukon SUVs can be ordered with available four-wheel drive. A single-speed transfer case system is standard on Yukons; a two-speed transfer case is an option on Yukon and Yukon XL; and Denali editions come with on-demand four-wheel drive. Cars.com explains the Denali's permanent 4WD is "distinct from the available part-time four-wheel drive on the regular Yukon."
On all versions, the steering feels light but not communicative, and bumps are positively smothered by the massive curb weight and big coil-spring suspension. The Yukon lineup boasts impressive handling for a vehicle of this size and pedigree, although it's not universally praised. Edmunds reports the "Yukon's steering, although precise, is too light for such a large vehicle." Kelley Blue Book contends that "ride quality...is hardly truck-like at all, and it feels secure in curves." ConsumerGuide also praises the "car-like comfort over bumps," and they note "long-wheelbase XL models are slightly more comfortable regardless of tire choice."
The GMC Yukon Denali models all get GM's Autoride electronically controlled damping system, which does a great job bringing good ride comfort and decent steering response through the big 20-inch wheels. Road & Track even reports that the "Yukon Denali [feels] surprisingly fleet of foot," with the "taut, well-tuned chassis [feeling] more car-like than truck-like in operation." Kelley Blue Book calls the 2010 GMC Yukon Denali "by far the best handling full-size SUV ever to wear a GMC badge," though ConsumerGuide isn't quite so impressed with the ride quality, stating that "impact harshness over sharp bumps is exaggerated by the short sidewalls of the available 20-inch tires." Braking is another strong point; ConsumerGuide says the "brakes offer no-drama stopping control with solid pedal feel." Jalopnik confirms "the four-wheel disc brakes worked with aplomb" during their road test. Overall, the Denali isn't tremendously maneuverable, but it handles surprisingly well on back roads; you'll quickly forget that you're piloting a 6,000-pound vehicle that can tow up to 8,600 pounds-"strong towing and hauling capabilities," as Edmunds describes it.