From jumbo jets to supersize fries, the United States runs on a principle of "big." Same goes for vehicle selection. For hundreds of thousands of new vehicle buyers, midsize simply doesn't cut it. For people who need maximum everything--from passenger space to towing capacity--the only choice is a large SUV.

Around the turn of the century, large SUVs enjoyed a large amount of success, selling more than 1 million units annually. The market has shifted towards smaller, midsize and crossover-type vehicles since then. Some industry analysts predict large SUV sales will drop, and then hold steady, at less than 700,000 units per year. This is bad news for automakers as these vehicles are typically the most profitable.

General Motors, Ford, Nissan, and Toyota all sell large SUVs. GM and Ford have dominated this segment with combined market share of more than 70 percent. GM's Chevrolet Tahoe and Suburban and GMC's Yukon and Yukon XL, along with Ford's Expedition control the large SUV market, with a combined share of more than 70 percent.

The domestic makers introduced new versions of their large SUVs for 2007. GM's SUVs have a new platform, styling, and interior. Ford's Expedition boasts freshened styling inside and out, and it now offers an extended wheelbase model called Expedition EL. It's 15 inches longer than a standard Expedition and is designed to compete with the Chevy Suburban and GMC Yukon XL.

The only change of note for the Nissan Armada is more power on '07 models (317 horsepower versus 305). Toyota's Sequoia gets standard curtain side airbags on '07 models. They were optional on previous versions.

Under the Skin
Besides brawny styling, large SUVs derive much of their engineering from workhorse large pickups--this means plenty of power, towing, and cargo-hauling capability. They can also tackle tough terrain when asked (and properly equipped).

Most offer a choice of rear- or 4-wheel drive. Unlike many systems found in large pickups, 4WD mode on large SUVs can be left engaged on dry pavement. These systems also include a low-range gear for serious off-roading.

For most folks living in drier climates, a rear-drive version will do just fine. It's usually not worth the added penalties in weight, fuel economy, and sticker price versus a 4WD model. For those living where rain reigns, snow is supreme, or off-road adventure is on-tap, 4WD becomes a needed asset.

But with the benefits of truck-type platform, very distinct drawbacks also arise, regardless of drive wheels. Sloppy handling, a bouncy ride, high fuel consumption, and hefty sticker prices are common criticisms. Manufacturers are working to mitigate those issues as much as possible, while still delivering all the features buyers expect.

One such method to help increase fuel economy is a technology commonly known as cylinder deactivation. Under cruising and light throttle conditions, an engine with this feature will shut off half its cylinders. General Motors employs cylinder deactivation, dubbed Active Fuel Management, in most of its large SUVs, including the 2007 Chevrolet Tahoe and Suburban, as well as the GMC Yukon. Company officials say Active Fuel Management can increase gas mileage by about 7 percent, depending on driving conditions.

You Can Take it With You
Whatever power configuration you choose, any large SUV is designed for maximum versatility. For hauling people, three-row eight-passenger seating arrangements are common. A few, like the Chevrolet Tahoe/Suburban, GMC Yukon/Yukon XL, and Ford Expedition can seat nine when properly equipped. As is the case with a lot of three-row SUVs and minivans, the furthest aft seating positions are best left to children since space there is at a premium.

Should cargo hauling be a top priority, a large SUV can be a good choice. Depending on model, the third-row seat can be folded flat atop or into the cargo floor or removed entirely. Same goes for the second row. Many offer seats that can also tumble forward, increasing cargo space or providing easier access to the third row. When all rear seats have been removed or folded, most large SUVs offer at least 100 cu-ft of cargo capacity.

 A power fold and tumble second-row seat is an industry first for the newly available 2007 Chevrolet Tahoe and GMC Yukon. The 3rd row in the GM SUVs must be removed in order to obtain a flat loading floor. Ford's Expedition is available with a third row that power folds into the cargo floor.

While cargo capacity is slightly less than most minivans, a large SUV boasts more robust towing capability. Be it a party boat, horse trailer, or custom hot rod, a large SUV is geared for heavy duty hauling. A 6500 lb maximum is considered the low end of the spectrum in this class. The highest-rated models can tow in excess of 9000 lb. For more information, consult the specification chart below.

Most large SUVs equip their transmissions (all use automatics) with special "tow/haul" buttons. When activated, the transmission adjusts shift points to cope with a trailer or heavy loads. All models in this class offer as standard or optional a load-leveling suspension. When the rear has a lot of weight, the suspension automatically rises to compensate.

Safety First
Just because these SUVs are large doesn't mean they skimp on safety features. Antilock brakes are pretty much standard across the board, as are curtain side airbags that are designed to protect passengers in all three seating rows. On the base models of the Chevy Tahoe and GMC Yukon, the latter are disappointingly optional. For the peace of mind curtain airbags offer, we strongly urge you to not have a vehicle without them.

So that those airbags may never need to be used, large SUVs incorporate some other mechanical safety features. Most notable is stability control, also known as an antiskid system. Antiskid systems are designed to keep a vehicle on an intended path on slippery roads. Some antiskid systems also incorporate sensors that can detect an impending rollover. Since large SUVs are heavier and often have higher centers of gravity than midsize SUVs or cars, this technology is something well worth considering.

As always, though, these safety features are designed to be used in conjunction with safe, prudent driving. Just because a vehicle is equipped with four-wheel drive and stability control doesn't make it invincible.

Little Things in Big Packages
With robust capabilities, large SUVs can also pamper drivers and passengers alike with a variety of luxury and convenience features. Things like leather upholstery and individual climate controls for front and rear passengers are common. Other available features on most large SUVs include navigation systems, rear DVD entertainment, and power-adjustable pedals. Most offer power tailgates and rearview cameras. The rear glass is power operated on the Toyota Sequoia for added convenience.

Costs of Ownership
Large SUVs aren't cheap, from any standpoint. Their sticker prices tend to be much higher than comparable minivans or midsize SUVs. Further, repair costs can be high, especially on four-wheel-drive models. Since demand is dropping, resale values will suffer. And last, but certainly not least, there's these vehicles' hefty appetite for fuel.

In spite of all this, if the idea of owning a large SUV is appealing to you, the choices in this class are excellent overall. The key players have done admirable jobs creating vehicles that live up to what buyers should expect from vehicles in this class.

Ford has innovative features, like its power-folding third-row seat. GM's Tahoe and Yukon enjoy the largest market share and offer smooth, powerful engines. Nissan's Armada is near the head of the class in towing at 9100 lb. Toyota's Sequoia rides very well and comes in a slightly smaller and more maneuverable size. Check out the full Consumer Guide(r) reviews for more details, and be sure to test drive all of them to see which one most suits your needs.

Chevrolet Suburban Base Price Range: $36,860-$41,605 EPA MPG Range: 14-21 Body Style: 4-door wagon Chevrolet's 2007 redesign of this large SUV addresses the most egregious flaws of its predecessor: sloppy steering and subpar interior appointments. For smooth power, utility, and surprising overall refinement, Suburban is a Best Buy value among large SUVs.

Chevrolet Tahoe Base Price Range: $33,855-$38,420 EPA MPG Range: 15-21 Body Style: 4-door wagon Chevrolet's 2007 redesign of this large SUV addresses the most egregious flaws of its predecessor: sloppy steering and subpar interior appointments. Third-row accommodations are still best suited to children, but for smooth power, utility, and surprising overall refinement, Tahoe is a Best Buy value among large SUVs.

Ford Expedition Base Price Range: $29,175-$42,575 EPA MPG Range: 14-20 Body Style: 4-door wagon Expedition is an excellent vehicle for those who genuinely need the power and space of a large truck-type SUV. Interior materials trail those of some competitors, but for useful power, cargo space, passenger room, and surprisingly adept handling, this Ford is a Recommended pick.

GMC Yukon and Denali Base Price Range: $34,565-$50,185 EPA MPG Range: 13-22 Body Style: 4-door wagon All of GM's redesigned 2007 large SUVs improve on their 2000-2006 predecessors in handling, refinement, comfort, and interior design. Yukon is pitched as an upscale alternative to Chevrolet's Tahoe, and Denali is positioned just below Cadillac's Escalade.  Despite having more power and luxury touches than Yukons, Denali doesn't deliver enough of either to justify its higher base prices and thirst for premium-grade fuel. A carefully optioned Yukon SLE or SLT are our Best Buy values in this GMC lineup.

Nissan Armada Base Price Range: $34,950-$43,050 EPA MPG Range: 13-19 Body Style: 4-door wagon Armada doesn't lead the large-SUV class in any area. It also trails key rivals in 3rd-row comfort and ease of entry/exit. Still, engine performance is laudable, and prices generally undercut those of similarly equipped competitors. Despite quality gaffes in some of our test models, Nissan does have a good reputation for mechanical reliability.

Toyota Sequoia Base Price Range: $33,160-$45,660 EPA MPG Range: 15-18 Body Style: 4-door wagon Sequoia suffers the usual big-SUV vices, but it merits our Recommended badge as a refined, well-equipped Toyota. Still, top domestic-brand rivals match it in many ways while typically towing more than Sequoia's 6500-lb maximum. They usually carry bigger price discounts, too.