At the rear, there's a convenient and practical step in the center of the rear bumper, sort of a big functional notch. But the twin round taillights stacked over the backup light at each corner are kind of lumpy and googly eyed.

Overall, TrailBlazer looks sturdy and neat, with confident lines that express utility. The pillars and window lines are graceful, while the headlamps and turn signals (split by the grille crossbar) are stylish. Big fender flares visually express the vehicle's boldness, and may be either body color or silver.

Still, the most dramatic feature of the TrailBlazer may be what's under its hood: not a V6, but an all-aluminum, double-overhead-cam, 24-valve engine with variable valve timing and six cylinders lined up straight in a row.

Inline sixes were once the industry norm. An old reliable straight six served as the base-level power plant in Chevrolet trucks (and passenger cars) from 1929 right into the mid-1980s. Jeep still runs a straight six in the Cherokee. BMW and Lexus build some of the most sophisticated sixes in the world, and both companies prefer an inline configuration. An inline six is inherently smoother than most V6s, and simpler as well; whereas a V6 takes up less space, and a 90 degree V6 can be manufactured using V8 tooling, two reasons for the soaring popularity of V6 engines in the 1980s and 90s. Now, however, thanks to advancements in electronics, metallurgy and manufacturing, the straight six is poised for a comeback.

The TrailBlazer's Vortec 4200 is no ordinary straight six. From 4.2 liters, it produces a stunning 275 horsepower, 35 more than Ford Explorer's optional 4.6-liter overhead-cam V8. And it has a very broad torque curve, peaking at 275 pounds-feet, only 7 pounds-feet less than the Ford V8, and 400 rpm sooner. The Vortec also features electronic throttle control, an electrical system using silicon circuit boards (replacing some 1100 feet of copper wire), coil-on-plug ignition (thus no plug wires), and a seven-quart oil pan with a clever tunnel for the front drive axle, which allows the longish block to be mounted six inches lower, contributing to better balance and a lower center of gravity.

Because the engine is so quiet and smooth at idle, a feature called "intellistart" was added which prevents the starter from grinding if the key is turned when the engine is already running. With a mixture of amusement and pride, GM engineers report that this happened to them all the time during development.

Attention to detail in other places is evident, from a battery box that draws in cooling air, to remarkably sanitary wiring under the hood, to rear-seat headrests that conveniently flip down for better rearward driver visibility.

The TrailBlazer's Autotrac system, standard on 4WD models, features four settings: 2WD, Auto4WD, 4HI and 4LO. In Auto, which shifts power to all four wheels as conditions require, the TrailBlazer can be towed without having to disconnect the driveshaft, a very convenient feature. Switching in and out of 4WD can be done on the fly with a flip of the switch, although the transmission must be in neutral to engage or disengage 4LO.

The chassis and suspension are also highly developed, featuring a list of sports car stuff: rack-and-pinion steering, beefy four-wheel vented discs with twin-piston calipers in front, independent front suspension with short/long control arms, solid rear axle using five-link location with Bilstein gas-charged shock absorbers and coil springs, thick antiroll bars front and rear. It was the first truck for the TrailBlazer's chief designer, Ted Robertson, who brought a resume to the assignment that includes the '90s Camaro/Firebird. GM wanted his soul as well as his experience in their midsize SUVs, and they got it. His approach was to put some "sport" in Sport Utility.

The standard-wheelbase TrailBlazer is 8.3 inches longer and 6.9 inches wider than the old Chevy Blazer. The track (the distance between the left and right tires) is the widest in the class, 2.2 inches wider than the Explorer in front and 0.9 inches wider in rear. Still, the TrailBlazer has a very tight turning circle of 36.4 feet, because the suspension and engine design allow for large steering angles.

Finally, the chassis rails are shaped by hydroforming, a process pioneered in the '97 C5 Corvette; it makes the rails stronger and lighter. No less than eight crossmembers contribute to a claimed 260 percent increase in torsional rigidity, and there are 12 tuned body mounts made of urethane.