This year brings a new line of sport utility vehicles from General Motors. Developed on a clean sheet of paper, the 2002 Chevrolet TrailBlazer, GMC Envoy, and Oldsmobile Bravada are longer, wider, and more sophisticated than the namesakes they replace.
The most significant development is a new engine. Instead of the V-6 or V-8 found in Ford’s Explorer and Mountaineer SUVs, GM opted for an all-new in-line six-cylinder. Many of us grew up around straight sixes. Chevy trucks used a reliable straight six in the old days, and Jeep has long used a basic straight six in the Cherokee. An in-line engine is, in fact, inherently smoother, simpler, more durable, and more fuel-efficient than a V-6. But the in-line configuration is also longer and, until recently, has been stuck in a cast-iron shell. Advancements in electronics, metallurgy, and manufacturing methods, however, have enabled GM to make this proven design sing a new high-tech song.
The new 4.2-liter in-line six, called the Vortec 4200, uses an aluminum block and head, double overhead cams, four valves per cylinder, variable exhaust-valve timing, electronic throttle control, and coil-on-plug ignition (no spark-plug wires). An advanced powertrain control module (a.k.a. computer) manages all of the engine and transmission functions for optimum performance and shifting. A 7-quart oil pan features a clever tunnel for the front drive axle that allows the long block to be mounted 6 inches lower in the engine bay, contributing to better balance and a lower center of gravity. It’s so quiet and smooth at idle that an interlock was added to keep people (including GM engineers) from grinding the starter when the engine was running. This engine is nearly 50 pounds lighter than existing V-6 designs.
But what about power, you ask? The Vortec 4200 generates 270 horsepower?30 more than the Explorer V-8. (And there’s easily another 30 horsepower available just by adding aftermarket dual exhausts, according to GM engine designer Ron Kociba.) More important, the Vortec 4200 offers a very broad torque curve that peaks at 275 foot-pounds.
The Chevy TrailBlazer 4WD is rated to pull a 6,200-pound trailer. That’s a bit less than the Explorer 4×4 V-8’s 7,000 pounds. In response to this, GM’s marketing people point to their six-cylinder engine’s flatter torque curve and the live rear axle used in place of Ford’s new independent rear suspension. Tow ratings don’t tell the whole story, they say. “There’s no industry standard on calculating towing capacity,” says Doug Lease, assistant brand manager of marketing for the Chevy TrailBlazer. “GM’s towing capacity ratings are the most conservative in the industry.” An independent rear suspension squats down when heavily loaded, he explains. Real trucks use solid rear axles.
Maybe there’s something to that. In theory, a live rear axle offers a more stable platform for towing, better offroad capability, and better durability. An independent rear suspension, on the other hand, excels at ride quality and on-road handling. In any case, rear suspensions are a key engineering difference between GM’s TrailBlazer, Envoy, and Bravada and Ford’s Explorer and Mountaineer. My TrailBlazer LTZ was equipped with the standard 3.73:1 rear end differential, but two other ratios are available: 4.10 for better towing and 3.42 for better gas mileage. All three trucks come standard with a transmission oil cooler, a Class III receiver integral to the frame, and a seven-wire plug with cover conveniently located next to the receiver.
As for handling and ride quality, the TrailBlazer swings into tight parking spaces easily, a benefit of the narrower straight-six engine, which gives engineers room for more flexibility with wheel angles. In fact, the turn radius is 6 feet tighter than that of the old Blazer, which is shorter and narrower.
Though the Chevy TrailBlazer, GMC Envoy, and Oldsmobile Bravada look radicaally different, they are nearly identical mechanically. They use the same engine, transmission, chassis, and suspension. From a practical standpoint, there are three key differences that give the TrailBlazer and Envoy the edge over the Bravada.
First, the traditional rear axle and suspension of the TrailBlazer and Envoy are better suited for bouncing around in rough terrain than the standard load-leveling suspension of the more luxurious Bravada. (I have to admit that this system provides an outstanding benefit. A 22-foot air hose that attaches to the suspension’s silent air compressor through a small valve hidden inside a cargo area compartment can be used to reinflate tires.)
Second, the TrailBlazer and Envoy have drivetrains more appropriate to the needs of hunters and fishermen. All three SUVs can be ordered with either four-wheel-drive (GM’s Autotrac system) or two-wheel-drive (the latter with traction control). However, 4WD TrailBlazers and Envoys come with a rotary switch allowing the driver to select among four settings: 2WD, Auto 4WD, 4HI, and 4LO. Under normal driving conditions, the Auto 4WD mode directs 95 percent of the power to the rear wheels; it automatically directs more power to the front wheels whenever it detects rear wheelspin. The Bravada does not come with the switch; it’s always in Auto 4WD. You cannot shift the Bravada into low range.
Third, the Bravada will likely be the last all-new vehicle from Oldsmobile. GM intends to retire America’s oldest mass producer of gasoline cars within three years. Though Oldsmobile is going away, the brand is offering longer warranties, which GM will have to honor.
All three trucks come standard with all-season tires. Optional 17-inch BFGoodrich tires are designed for better traction offroad. A locking rear differential is also available for $270?an important option that transfers traction between the right and left wheels. Ground clearance is just 8 inches, more than an inch less than the Explorer’s. Order the optional skid plates if you plan any offroad driving.
The new models are considerably larger than the versions they replace. The TrailBlazer, for example, is 6.8 inches wider and 8.5 inches longer than the Blazer; its 113-inch wheelbase is 6 inches longer. This gives the new models far more interior space.
Taking advantage of that cargo space is as easy as folding the seatback down and flipping the seat forward. As on the Tahoe, the headrests fold up as the seat is folded down. This reveals a relatively flat cargo floor. Cargo capacity is rated at 80.1 cubic feet, and shoulder harnesses are used at all five seating positions.
Like the other new GM trucks, the TrailBlazer comes with daytime running lights, but pressing the dome light four times turns them off. An auxiliary power receptacle is just inside the rear cargo door, conveniently located for running compressors and other outdoor accessories.
Prices for 4WD models (including destination charge) start at $27,980 for a TrailBlazer LS and top out at $34,330 for leather-lined LTZ models. The 4WD Envoys run $31,645 to $34,420.
Now armed with great midsize SUVs, GM will be fiercely competing for your business at a time when sales are leveling off. Outdoorsmen planning to buy one of these SUVs will surely benefit.