General Motors must be hoping history doesn't repeat with the launch of its all-new do-or-die group of 2007 GMT900 SUVs. When Gas Crisis I sucker-punched the Big Three in 1973, GM's U.S. market share was more than 43 percent, most of it based on big, full-size V-8 cars. (GM's market share is now in the mid-20s). Some 33 years later, General Motors says its big sport/utilities sell nearly 750,000 units annually, with 6.5 million owners, and that it owns 62 percent of the segment. So with GM profits far below expectations, the GMT900s were pulled forward, rushed to market six months early, arriving just in time for Hurricane Katrina to mess with our oil supply, driving gas prices (at one point) up to $3.50 per gallon.

Against this backdrop, even the most optimistic GM insiders must be concerned that the troubled giant's future hinges largely on the success of the big Chevrolet Tahoe, Suburban, and Avalanche; GMC Yukon, Denali, and the XL versions; and Cadillac Escalade, ESV, and EXT in 2006. The 116-inch-wheelbase Tahoe, Yukon, and Escalade launch within weeks of each other in the first quarter; the others, the larger 130-inch-wheelbase models, launch in the second quarter.

The good news is the GMT900s are vast improvements over the aging 800s. Precise, responsive rack-and-pinion steering with the best feel and feedback in the segment, plus pushrod V-8s with variable valve timing and fuel-saving Displacement on Demand cylinder shutoff, distinguish the GM models over other big SUVs. The automaker expects combined EPA fuel mileage of 20.5 mpg for its 5.3-liter V-8 rear-drive models, and 20.1 mpg for 4x4s. A two-phase hybrid will be available in 2007.

Fit and finish is excellent on the new models. Small, tight panel gaps and one-piece front fascias eliminate the big, gaping openings endemic to GM products. The new interiors are improved, with GM's new chrome-ringed dials and quality switchgear, good leathers, and no more mouse-fur headliners. The Cadillacs, at least (and we expect the GMC Denalis) should have real-wood accents (like Mercedes, BMW, and Audi) beyond simple steering-wheel details. Most important, though, the interiors equal those of the competition. A power-operated flip-and-fold second row is optional, and power hideaway runningboards will be available several months after launch.