Many have asked how many platform-sharing vehicles can General Motors keep coming up with. Certainly, the GMT 360 platform (Chevy TrailBlazer, GMC Envoy, Oldsmobile Bravada, and Buick Rainier) has been quite versatile and could spawn even more variations. Now the stretched versions (GMT 365) of the TrailBlazer and Envoy (called the EXT and XL, respectively) are out, offering 16 more inches of wheelbase and overall length; however, the most significant benefit is a decent- size third-row seat. The newly designed tumble-forward second-row seats allows for easier rear cargo or third-row-seat entry. In addition, there's about 20 extra cubic feet of interior cargo capacity when the second- and third-row seats are folded flat.

The extra wheelbase required engineers to re-tune the steering feel (slowing it down just a tad) to allow the longer vehicle to maintain its softer road manners. Our guess is that there will be many SUV buyers looking for the added space and seating capacity but don't want to jump into the larger categories of the Suburbans or Expeditions.

Engine options will begin with the Vortec 4200 straight-six, but will eventually include the new all-aluminum Vortec 5300 V-8 at a later date.

Of note, the extra 16 in. of the EXT adds about 400 lb, allows for 200 extra lb of payload capacity over standard-length TrailBlazers, yet offers less overall trailering capacity (6400 versus 6000 lb). What does it all mean? Maybe little, other than GM is hoping there are people who want to stay out of minivans so badly, they're willing to pay the extra money for a stretch midsize. To us the proportions seem a bit out of whack, but the idea has potential. Look for EXTs to go on sale later this year and start just under $30,000.