First Test: 2009 GMC Yukon 2 Mode Hybrid

Likewise, GM engineers wanted to remove as much mass from the vehicle as possible. Outside, a new aluminum hood and liftgate replaces the steel units. A fixed rear glass gate saves weight as well as does the complete removal of a spare tire and jack. Thinner-profile front seats save 10 pounds each and give second-row passengers 1.5 inches of added knee room. Aluminum wheels, a slightly smaller fuel tank, and a 42-volt power steering unit also help save weight.

Perhaps more impressive than any of these details, especially to the bigger families and weekend warriors who gravitate to vehicles of this size, our GMC Yukon 2-Mode Hybrid sacrifices little towing, payload capability, or passenger space. The Yukon still can carry up to eight people, tow a 6100-pound boat, and tote more than 1400 pounds of gear. And at the track, the system, with a slightly larger engine, proved faster in almost every way. We're usually skeptical when it comes to "no-compromise" solutions, but after driving this fuel-efficient full-size SUV, it looks as close as it gets. GM knows this is a long-term investment so it's willing to keep costs reasonable for now (some speculate GM is subsidizing between $8000 and $10,000 per vehicle), with the hope that the same windfall that blew over Toyota with Prius, might happen for the General. In the meantime, 2WD Yukon Hybrids will start at $50,945, with 4WD models $2810 more.

Cadillac's Escalade 2-mode hybrid

With all the attention on the Chevy Tahoe and GMC Yukon 2-Mode Hybrids going on sale in January, some might wonder where the Cadillac Escalade is in all this. Isn't it supposed to be the technology leader within GM? Although Cadillac says the Escalade was part of this rollout plan from the beginning, it won't be getting this hybrid system until the summer, almost six months after Chevy and GMC. But don't expect to find any of the same aero, body, or physical changes on the Cadillac that are part of its Chevy and GMC brothers. Cadillac says it's not about compromise, so the Escalade will keep its full-size spare, steel rear hatch, glass release, and standard hood as well as all those cushy interior seats. However, it'll most likely carry the bigger premium price-tag Cadillac buyers will be more willing to pay. There seems to be something about this luxury class that loves being environmentally friendly. No word yet on pricing, but we'd expect Escalade 2-Mode Hybrids to start around $60,000.