GM's trusty 5.3-liter Vortec V8, making 310 horsepower and 335 pound-feet of torque, is one of the best V8s around, and when you floor it, it actually feels like it has more horsepower than that, considering the weight of our test vehicle was 5757 pounds. There's a smooth four-speed automatic transmission to go with it, and with all that torque, a fifth speed in the transmission might not be needed, although the big Japanese V8 SUVs all have five-speed automatic transmissions.

If you need more power for towing, you can upgrade to the 2500 (three-quarter ton) chassis and/or the 6.0-liter engine, to get 380 pound-feet of torque. Or the Denali XL, with that Corvette-based 6.2-liter engine making 380 hp and 417 pound-feet.

There's a badge on the rear of the vehicle that says "FlexFuel," meaning the engine can run on either unleaded regular fuel, or E85 (85 percent ethanol and 15 percent gasoline), which burns cleaner and reduces oil consumption.

Active Fuel Management shuts down four of the eight cylinders when they're not needed to save fuel. But there's one big catch: all the cylinders are needed virtually all time, unless you're totally off the throttle, in which case they all basically shut down anyhow. So the amount of fuel saved is questionable and debatable.

Fuel economy is an EPA City/Highway-rated 15/21 miles per gallon. We drove nearly 300 miles in a 2WD Yukon XL in an even split between around town and running 75 mph on the freeway, and averaged 15.8 mpg.

Ride quality is excellent, overall. The suspension seems much improved over undulating roads; wallowing under duress has been a weakness of Yukons and Suburbans in the past. The new fully boxed frame is 49 percent stiffer and 35 percent more resistant to twisting. The front track has been widened by three inches, and the rear by one inch. A new coil-over-shock front suspension, and revised and strengthened five-link rear suspension around a solid rear axle (better for towing) work well with new rack-and-pinion steering.

AutoRide, the optional self-leveling suspension, is a high-tech, active suspension, meaning it electronically adjusts to the road, as read by sensors. It reduces body lean in corners and nose dive under hard braking.

Driving in an estimated 25-mph crosswind on the freeway at 75 miles per hour, our Yukon XL swayed all over the road, because of the billboard-like surface area of the side of the vehicle.

The brakes have gotten a much-needed upgrade. The vented rotors are bigger (13 inches in front and 13.5 inches rear) and the dual piston calipers are stiffer. This adds up to security and safety when you're trying to get stopped with a boat or trailer pushing you from behind. Brakes on these new GM trucks are far better than they were a decade or so ago.