Not so, though, the Yukon Denali, which would leave its lesser sibling and all the others in the dust were its driver so inclined. The Denali packs a 380-hp 6.2-liter V8 and six-speed automatic.

Fuel economy is a much better story for the new Yukon. The 2WD and 4WD versions each earn an EPA combined City/Highway estimate of 18 mpg. That's not exactly Toyota Prius territory, but the Yukon's Active Fuel Management system, which shuts down half of the engine's cylinders under light load, puts the 2007 Yukon at head of the class in the fuel economy competition. Both the 2WD and 4WD Yukons best all of the competition in EPA Highway estimates by as much as four miles per gallon.

In towing, the Yukon's 7700-pound rating beats the Toyota's 6500-pound rating, while Ford and Nissan rate their entries at a maximum of 9100 pounds.

From the driver's seat, much of this is not noticed. Power comes on smoothly, with no surges or hiccups and accompanied by a pleasant, dual exhaust-like tone. Transitions effected by the fuel-management system are invisible, with the only indication a telltale in the information display in the tachometer. The four-speed automatic selects gears with little fanfare. The six-speed automatic in the Yukon Denali is even smoother; the new six-speed automatic also has a manual shift function managed by a rocker switch in the handgrip on the column shift lever.

While trucking along twisty, two-lane roads in Georgia and on coastal California roads, the Yukon tracked flat and smooth through 70-mph sweepers marked with 40-mph advisories. The ride was comfortable and controlled on South Carolina freeways, both glass-smooth and buckled from severe winters. For this, credit the rack and pinion steering, which is new for 2007, that delivers sharper, more precise turn in, along with a stronger and stiffer frame; new, coil-over-shock independent front suspension; revised, multi-link, live axle rear suspension; and a wider track, by some three inches in front and an inch in the rear. The turning circle impressed us. It takes less space to make a U-turn in a Yukon than it does in other SUVs in this class; even some relatively small vehicles such as the Mitsubishi Eclipse need more space to turn around than the new Yukon. This is helpful in a world of big SUVs and compact parking spaces.

We found the brake pedal solid and firm, with a prompt and confident response. The new Yukon's disc brakes are larger than those on the previous-generation model, by almost an inch in front and by more than a half-inch in the rear, with dual-piston calipers that are 50 percent stiffer than before.

Abundant sound deadening material mutes road noise, but wind whistle easily leaks around the multiple door seals. That the stereo has to be on for the navigation system to operate is irritating, a strategy shared with expensive Mercedes vehicles. We like that GM vehicles now provide off switches for the daytime running lights and for the inside rearview mirror's auto-dim function.

Summary

The 2007 GMC Yukon has an astonishingly fresh and comfortable interior. Its sleek, new body is mounted on a new, stronger and stiffer frame and there's also a new power steering system, beefed up brakes, new front suspension and re-worked rear suspension. It's easily the best Yukon we've ever driven. With all these improvements, the Yukon is now a strong contender with other full-size SUVs.

[While preparing his report, New Car Test Drive correspondent Tom Lankard drove new Yukon models around Greensboro, Georgia, and Carmel Valley, California.]

Model Line Overview

Model lineup:GMC Yukon SLE 2WD ($33,815); Yukon SLE 4WD ($37,615); Yukon SLT 2WD ($37,995); Yukon SLT 4WD ($40,795); Yukon Denali ($47,115)

Engines:290-hp 4.8-liter V8; 320-hp 5.3-liter V8; 380-hp 6.2-liter V8

Transmissions:4-speed automatic; 6-speed automatic

Safety equipment (standard):dual-stage front airbags; second-row seat child safety seat anchors (LATCH); third-row seat child safety seat tethers; four-wheel antilock brakes with Dynamic Rear Proportioning; Stabilitrak stability control system; tire pressure monitoring system; OnStar emergency notification system with one-year pre-paid subscription

Safety equipment (optional):roof-mounted, full-coverage, side curtain airbags ($350; standard on SLT and Denali); rearview camera system ($195; available on SLT and Denali only); rear park assist ($245; standard on Denali)

Basic warranty:3 years/36,000 miles

Assembled in:Arlington, Texas; Janesville, Wisconsin