Driving the 2015 Chevy Tahoe, Suburban and GMC Yukon, kings of the SUV hill

While the weather that recently terrorized California was a headache for the locals, it proved to be a stroke of luck for those test driving General Motor’s latest line-up of full-size SUVs during the last week in February. As we made our way from Lake Tahoe in the Sierra Nevada mountain range to Napa Valley in the heart of tranquil wine country, the climate changed from a driving snowstorm with high winds and white-out conditions, to a mix of sleet and rain, to pouring rain with patches of dense fog, and finally to beautiful clear skies and sunshine. We couldn’t have asked for a more diverse variety of climes under which to push these extra-large people movers to their limits.

For the first time since 2007, GM is completely overhauling its line-up of full-size SUVs -- namely the Chevy Tahoe; its long-wheel based cousin, the Suburban; and the GMC Yukon. (The all new Cadillac Escalade is not due till later this year.)

Updating these big gas-guzzlers might sound like a fool’s errand; full-size sport-utes have lost considerable market share to smaller, more efficient vehicles like the Ford Explorer and Toyota Highlander, and that trend appears irreversible. But GM executives say there will always be a need for extra-large people movers as long as there are large families that like to hike, bike, and tow stuff.

It's also no secret that full-size SUVs are the automaker’s most profitable category. The Tahoe, Yukon and Suburban account for more than 70 percent of the big SUV market, and since the profit margin on these mighty machines is 10 to 20 times greater than more popular offerings like the Chevy Malibu, full-size sport utes account for almost 20 percent of the company’s gross profits.

They also suggest that GM cannot screw up this redesign – the profits only come in as long as the vehicles continue to sell.

All three ride on a similar — but not the same — chassis as the new Chevy Silverado pickup. While GM was careful to keep the basic look, it made subtle variations in the sheet metal so people could better tell the big people movers apart. The Chevy Tahoe and Suburban feature a boxier, more in-your-face front-end design with stacked projector beam headlamps that wrap that around the front fenders like cat eyes. The overall look works on the larger Suburban but not on the Tahoe; it makes the smaller SUV appear to have disproportionately bigger upfront.

The GMC Yukon and Yukon XL have a more aerodynamic hood with a mesh grille and matching head and tail lamps front and back. The top-spec Denali versions get their own unique grille, HID headlights, Denali-specific 20-inch wheels, and illuminated power-retractable running boards. The look is definitely more visually appealing than the Tahoe/Suburban.

All three vehicles feature new door designs to lessen noise within the cabin. Doors are now tucked up tight into the body, instead of wrapping up into the roof, and the windows have an acoustic laminate layer. The result is a cabin that is whisper quiet like a luxury automobile.

Overall, these full-size people movers look familiar – tall and upright with lots of hard, straight edges – yet somehow the subtle modifications come together to achieve a modern look that's sportier than the outgoing models.

While the new wrappers are impressive, the filling is to die for. GM has given each a more luxury car-like interior, complete with upscale materials, lots of soft-touch surfaces and enhanced ergonomics. In the more rarified trims (LTZ, SLE, and Denali), the sport-utes have also been outfitted with a host of driver assist features.

The most noticeable upgrade arrives in the dashboard, transformed from its bland predecessors to a modern style. The different gauge clusters (Tahoe and Suburban were identical, while the Yukon was different, bit more configurable) were easy to read and provided a lot of customization. And the center console sports several useful storage compartments, including a pocket for a laptop computer. One of the most welcome features in the 8-inch color touch screen with MyLink infotainment system, mounted in the center of the dash. It synched seamlessly with my iPhone 4S and was easy to use, relatively speaking, without being too distracting.

Up front, the bucket style seats are more supportive yet somehow softer and less fatiguing, with more headroom. The second row seat also offers 2 inches more legroom, and is also easier to enter and exit — as is the third row — thanks to shifting the B-pillar forward.

But the biggest, most welcoming, change in terms of seating is that the third-row bench is no longer removable. Instead, it’s fold-flat. While you lose almost 14 cubic feet of storage between the old and new models in this configuration (with the second row seats folded flat, you’ll have only 94.7 cubic feet of storage to work with), you gain much more in terms of convenience. That third row bench seat was a hassle, at best, to remove and store. Plus, thieves loved to steal them and sell them back to desperate owners on eBay. The models we drove at the press preview were equipped with a power auto-folding third row and flip-and-fold second-row captain’s chairs.

We left Lake Tahoe in a driving snow storm in a Tahoe LTZ with 4WD. The white stuff had been falling for hours, so the roads were slick, but passable, and visibility was less than ideal. As we climbed into the Sierra Nevada mountains towards Sacramento, the conditions worsened – the snow became heavier, wind blew harder, road became slickerand visibility was reduced to less than a quarter mile. Even so, the four-wheeler (price as tested $66,645) powered through it without hesitation, handling the wet and sloppy with aplomb.

GM’s all-new EcoTec3 5.3-liter V-8, which develops 355 hp and 383 lb.-ft. of torque, is standard equipment on the Tahoe, Yukon and Suburban. Though the big V-8 provided plenty of motivation and confidence as we climbed up and down the mountain, it seemed to be a little uncomfortable doing so. Below the frost line, the 5.3-liter was more than up to the task of propelling the Tahoe and Suburban forward.

Transferring that power to either the rear or all four wheels (four-wheel drive is optional) is a six-speed automatic transmission carried over from the out-going model with a Tow/Haul mode, with up to 8,500 lbs. of towing capacity.

A 420-hp, 6.2-liter V-8 is also available for the GMC Denali trims, and this engine turned the big vehicle into a locomotive. Press the accelerator and you get more power than you need, with a cherry exhaust note to match. With it, the Denali sprints from 0 to 60 mph in 6 seconds; the 5.3-liter is about a second slower.

Each of these full-size SUVs features cylinder deactivation, giving their V-8 engine the ability to drop to four-cylinder status under a light load. Both engines slip in and out of four-cylinder mode with no indication beyond the readout in the instrument panel. Consequently, the 2015 Chevrolet Tahoe and Suburban and GMC Yukon and Yukon XL get an EPA estimated 16 mpg city/23 mpg highway in two-wheel drive varieties, losing one mpg on the highway with four-wheel-drive. The Denalis with the 6.2-liter V-8 get 15 mpg/21 mpg in two-wheel-drive.

Ride and handling were also much improved. Even though the electric power steering was somewhat numb, it was accurate and responsive. GM also improved the truck's magnetic ride control, the adaptive suspension system. It is standard on the Yukon Denali, Chevy LTZ, and GMC SLE trims, and softened the bumps, keeping these hefty bricks on wheels from feeling top-heavy.

But the sticker shock remains intact. Base prices begin at $45,595 for a rear-drive Tahoe LS, rising to $60,490 for the LTZ. The Suburban starts at $47,300 for the LS with a similar escalation. And the GMC Yukon starts at $46,335 for the SLE with the Denali XL landing at $65,390 before options. (Adding four-wheel drive to any trim level is an additional $3,000.)

The Tahoe LTZ that we tested sported a window sticker in excess of $66,000 and the Suburban LTZ topped $70,000. The Denali XL we tested cost more than $77,000. You can haul your family up a lot of mountains in the new Tahoe, Suburban or Yukon — if you can ascend those daunting summits first.

Disclosure: The manufacturer provided transportation and lodging for this review