Driving Impressions

General Motors introduced its 2002 midsize SUVs (Oldsmobile Bravada, GMC Envoy, and Chevrolet TrailBlazer) to the international automotive press in Los Cabos on the tip of the Mexican Baja peninsula. We were able to clock about 100 miles of driving on rough and fast Mexican two-lanes-flat and climbing, straight and twisting-and a few laps around an off-road course with steep climbs and descents and 50-mph washboards. Mostly, we were dazzled by the Vortec 4200 engine. The new Vortec 4200 engine is highly sophisticated: an all-aluminum, double-overhead-cam, 24-valve inline six-not a V8. If a straight-six engine is good enough for BMW and Lexus sedans, why not an Oldsmobile truck? From 4.2 liters, it produces a stunning 270 horsepower, 35 more than the Jeep and 30 more than an Infiniti QX4, Acura MDX or Nissan Pathfinder. It incorporates state-of-the-art engine construction and electronic management, and yields an estimated fuel mileage of about 15/21 mpg city/highway. It features variable valve timing, electronic throttle control, coil-on-plug ignition 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. It's so quiet and smooth at idle that a feature called "intellistart" had to be added to prevent drivers (initially GM test drivers and engineers) from grinding the starter by turning the key when the engine is already running. And the faster it goes, the smoother it gets. With an official Mexican Highway Patrol escort along on the test drive, we felt free to squirt up to 100 mph, and found much to our pleasure how silky the inline engine is at 80 and above. The engine also has a very broad torque curve; 90 percent of its peak 275 pounds-feet is available at 1600 rpm, and it's still there at 5600 rpm. This enabled us to leap past Mexican trucks on steep uphill two-lanes with confidence, while allowing the transmission to do dramatically less downshifting. And when the full-throttle upshift comes at about 6000 rpm the engine is only striding, not screaming. The smooth-shifting four-speed automatic transmission is the proven Hydra-matic 4L60-E, used in GM applications from Corvettes to Cadillac Escalades. Our test model was equipped with the standard 3.73:1 rear end differential, with a 4.10 for more oomph in towing. The load leveling suspension uses electronically controlled air bladders fitted to the rear coil springs. It's intended to improve the ride while dealing with off-road nearly as well as the rugged coils. Road inputs are monitored by sensors that tell the system to inflate and deflate the bladders independently, leveling the load horizontally as well as vertically. Because the system uses a small (silent) air compressor, there's a standard 22-foot-long hose which when attached to a valve in the cargo area can inflate anything from tires to toys. We drove the Bravada back-to-back with the TrailBlazer, having the same chassis and suspension but without the air springs, and could clearly see the difference--especially over speed bumps (and those topes are ubiquitous in Mexico). Surprisingly, we found that the air suspension didn't significantly hamper high-speed cornering. And GM engineers at the introduction revealed that there is even an internal debate among them, about how much if any this tilt toward luxury handicaps the Bravada in the hard twisties. The chassis and suspension are also highly developed, with components that might be found on a high-performance sedan: hydraulically assisted rack-and-pinion steering, four-wheel vented anti-lock disc brakes with twin-piston calipers in front, independent front suspension, five-link rear suspension with Bilstein shock absorbers, and that sophisticated air-bladder mechanism on the rear coil springs for a smoother ride. The chassis rails are shaped by hydroforming, a process that makes them stronger and light

Final Word

It's ironic that GM execs have said that the Bravada was intended "to make a strong statement about the division." The division is, or will soon be, dead. So maybe the statement is about nostalgia. But Oldsmobile can go out with its head held high, over the quality and state-of-the-art engineering of its final vehicle.