2008 GM Trucks - From Top To Bottom

The smooth-shifting six-speed automatic sports twin Overdrive gears with Sixth being a super-tall 0.66:1 for effi cient and quiet cruising. While we liked the way the engine and transmission worked together most of the time, when you try to settle into an 80-mph interstate cruise, the transmission hunts for the right gear. When climbing even a slight grade, the unexpected Sixth to Fifth downshift is jarring, and it seems that with the engine's torque this shifting is completely unnecessary.

High-End Ride
We learned more as the miles tallied up. You can run this truck hard. The giant 275/55R20 tires deliver a lot of grip, so the Denali feels stable as it responds quickly to commands from the steering wheel, but there's not a lot of road feel. While the ride was firm for those up front, it was completely comfortable. However, our female test participants complained that the ride in back made them want to put on a sports bra because of the bounce. Upon hearing these comments, we did a quick back-to-back with a currentgeneration Ford F-150 Crew Cab and found that the Ford's ride did exhibit less boob bounce.

Another issue surfaced because of the beat-up strips of broken concrete that pass for roads around Detroit. The optional 20-inch chrome rims that were on our tester certainly look great, but compared to the Denali's standard 18-inch doughnuts, the larger wheel/tire combo delivers sharp inputs to the suspension that make their way into the otherwise quiet cabin. If ride quality matters to you, go with the smaller-diameter wheels. And based on our recent experience, driving an '07 Cadillac Escalade (also based on the GMT900 chassis), definitely stay away from 22-inch rims, as the ride was considerably worse with that option.

The Other Side Of The Tracks
The Chevrolet Silverado 1500 WT may have come from the same family tree as the GMC Sierra Denali, but the two branches must have been far from each other.

The silver-blue paint and steel wheels on our regular cab tester helped our imagination visualize magnetic door signs spelling out Bob's Construction or Bill's Plumbing. The workman-like feeling continued when we opened the driver-side door.

Our Silverado had a more rugged, work-oriented interior, compared to the Denali. Beyond the radio and seatbelts, you'd be hard-pressed to find shared pieces. The split bench seat is covered in soft but durable cloth. It could easily sit three across. The windows had cranks, not electric switches. The dash covering was durable vinyl with not even a hint of wood, real or fake. All of the controls were designed to be operable even with a gloved hand. This is a refreshingly simple interior that reminded the author of what trucks used to be like-designed for doing work and not much else.

Our first thought was that the interior would not be as comfortable as the Denali's, but this impression was incorrect. On the road, the bench provided a good seating position and reasonable support. What truly surprised us was the quietness of the interior. Because of the truck's aerodynamic exterior and extensive insulation and sealing, there is almost no wind noise. Road and engine noise are also suppressed.

A downright supple ride complemented the hushed interior. Unlike some live-axle trucks, the Silverado exhibited no axle hop under any circumstances we encountered. The rear end stayed planted, even over expansion joints at highway speeds.

One of the few options on our Silverado was the 4.8L V-8. Matched to a mundane Hydramatic four-speed automatic transmission and a shorterthan- stock 3.73:1 rear axle, the engine's 295 hp moved this 4,400 pounds briskly. The truck never felt slow, although the Denali would have blown its tailgate off because of its better power-to-weight ratio.