This mid-size SUV shares platforms with the GMC Envoy, Buick Rainier, and Saab 9-7X. It features body-on-frame construction and is available in LS, LT, and high-performance SS versions, with the latter offering a 6.0-liter, 395-horsepower V-8 engine and other functional and cosmetic upgrades. Base models are powered by a 4.2-liter in-line six-cylinder engine offering 291 horsepower, with a 5.3-liter V-8 optional. All engines are paired with a four-speed automatic transmission, but SS models get a heavy-duty version. Other SS-specific features included a lowered suspension, 20-inch wheels, and heavy-duty brakes with larger 12.8-inch front discs. The SS is available with either rear- or all-wheel drive. Major options on the TrailBlazer for ’07 include a Sun, Sound, and Entertainment package, which combines a power sunroof, rear-seat DVD entertainment system, Bose premium speaker system, XM Satellite Radio, and an AM/FM stereo with six-disc CD changer. Adjustable brake and accelerator pedals, head side-curtain airbags, inside rearview mirror with temperature gauge and compass, leather seating surfaces with eight-way-power driver and passenger seats, sunroof, and both factory- and dealer-installed running boards may also be ordered. StabiliTrak stability control is standard on all trims; curtain airbags are optional.