Proving It in the Desert: GM’s New Full-Size Trucks Put to the Test

General Motors let the hype simmer long enough on its new 2007 Chevrolet Silverado and GMC Sierra. We sat through a dog-and-pony show during that July heat wave in Milford, Mich., and all I got to do was touch some sheet metal and take home a notebook full of specs on the new GMT900 platform full-size trucks.

It was mid-October and Cindy Brauer, managing editor of Automotive Fleet, and I was finally about to get the hee-haws out in the Arizona desert and on a closed track at GM’s Arizona Proving Grounds.

Reaching the lineup of trucks in the morning, I noticed first off that GM didn’t get overly aggressive with the exterior styling, favoring instead strong yet understated lines, a broader stance and a faster windshield angle. GM made sure to further differentiate between Chevy and GMC styling this time around.

Stepping inside, GM left no stone unturned — the fit and finish raising the bar for a pickup. The redesigned “low and forward” instrument panel is a welcome change from the 90-degree angled dashboards of this truck’s previous generations and other manufacturers’ older models.

Both interior offerings, the “pure pickup” and the “luxury-inspired” interior of the SLT/LTZ trim are ergonomic, roomy, and refined. Fleet drivers will appreciate the storage options: the enormous 20.1-L center console, the locking under-seat storage, and the double glove boxes (on the pickup trim).

GM created the segment’s leading front legroom and rear head and hip room. Combined with the 170-degree rear access door, the big boys should fit in the back without complaint.

We headed into the desert in the Sierra’s “luxury-inspired” SLT trim. Why not call it straight out luxurious?  The SLT/LTZ trims are loaded with interior appointments that rival any upscale SUV.

Upon reaching the off-road course, I was thankful Cindy didn’t push me out of the driver’s seat.

The course was a hilly hardpack gravel road that brought us through sagebrush and cacti with a backdrop of redbrick red desert mountains. We cornered around giant boulders, hugged cliffs, dipped down through dry washes, and crested blind hills into the sun.

This is where the hee-haws come in.

Manufacturers are one-upping each other with more horsepower; indeed, we took every hill with plenty of power to spare. While pure horsepower is a relatively easy thing to market, you can’t really define suspension and handling on a spec sheet. And this is the driving characteristic that sets the new GM full-size trucks apart.

The drive is solid and balanced, owing to the new, fully boxed frame and wider front and rear tracks. The rack-and-pinion steering is responsive and inspires confidence. Dips were dampened by the superior isolation characteristics of the Hotchkiss-type rear suspension. The tires grabbed the gravel and didn’t let go.

Dave Brown, one of the GM engineers in charge of suspension and handling, rode with us for a leg. He started going on about how the steering system is mounted on the front frame’s engine cross member to eliminate slack or vibration.

I trail off when it comes to the tech talk, especially when I’m gripping the wheel and can simply feel it working beneath me.  

This horse was ready to give me more in both the power and handling departments. I was in the mood for a more serious desert stomping to fully articulate the suspension. Not on that day.

I surrendered the reins to Cindy. She is not tall and had a bit of a time entering the cab. As the truck has plenty of ground clearance, anyone under 5’-5” should consider the optional step bar.

The expansive hood took her some getting used to, but initial trepidation behind the wheel gave way fairly quickly as she found her comfort level. About 10 miles into the desert Cindy got to test the large-capacity brake system and StabiliTrak (standard on crew cab models) when we rounded a blind corner to face an oncoming tractor-trailer. In short, it works.

Later we jumped in another model and tore off again to assault the desert, paying no mind to the wooden box weighted to the truck’s capacity in the bed. We barely noticed.

The new cargo management system is worth mentioning. Whereas the old rails were mounted on top, the new side rails with dual tracks and 500-lb. load points produce many more combinations of storage boxes and racks. The spring-mounted liftgate is easy on the wrists, too.

The next day we tested the trucks at GM’s Proving Grounds in Mesa against the cones and competitors’ full-size trucks.

The slalom course confirmed my suspension and handling exclamations of the GMT900 platform trucks. I took the cones tight with no fishtailing and only a hint of tire squeal.

We pulled a horse trailer with ease through a wider slalom course close to the 10,500-lb. max tow weight.

Somehow, GM gave these trucks more interior room, bigger engines, better suspension, more payload and towing capacity and managed to make them 200 lbs. lighter than the previous generation. Kudos. The bar has been raised.

The new 2007 Chevy Silverado and GMC Sierra will have hit showrooms by the time you read this.