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 when Cindy Brauer, managing editor of Automotive Fleet, and I finally got to test these trucks in the Arizona desert and on a closed track at GM’s Arizona Proving Grounds.

Exterior Design: Subtle Yet Strong

Reaching the lineup of trucks in the morning, I noticed first off that GM didn’t get overly aggressive with the exterior styling. Instead, they favored 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.

Interior Upgrades: Fit, Finish, and Functionality

Stepping inside, GM left no stone unturned — the fit and finish truly raise 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” SLT/LTZ trim, are ergonomic, roomy, and refined. Fleet drivers will appreciate the storage options:

• Enormous 20.1-L center console

• Locking under-seat storage

• 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, even the tallest passengers should fit comfortably in the back.

Driving the Sierra: Luxury Meets Performance

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 desert mountains. We cornered around giant boulders, hugged cliffs, dipped through dry washes, and crested blind hills into the sun.

Power and Suspension: The Key Differentiators

Manufacturers are constantly one-upping each other with more horsepower. Indeed, we took every hill with plenty of power to spare. While pure horsepower is easy to market, suspension and handling are harder to define on a spec sheet. This is where the new GM full-size trucks truly stand out.

The drive is solid and balanced, thanks 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 part of the drive. He explained how the steering system is mounted on the front frame’s engine cross member to eliminate slack or vibration.

As much as I appreciate the tech talk, I was more focused on gripping the wheel and simply feeling the truck perform beneath me.

A Smooth, Confident Ride

This truck was ready to deliver more in both the power and handling departments, and I was eager for a more serious desert stomping to fully articulate the suspension. But not on that day.

I surrendered the reins to Cindy, who had a bit of a challenge entering the cab. With the truck's high ground clearance, anyone under 5’-5” should consider the optional step bar.

After getting accustomed to the expansive hood, Cindy quickly found her comfort level. About 10 miles into the desert, she got to test the large-capacity brake system and StabiliTrak (standard on crew cab models) when we rounded a blind corner and faced an oncoming tractor-trailer. In short, it works.

Cargo and Handling: Built for Heavy Loads

Later, we jumped into another model and took off again, this time with the truck’s bed weighted to full capacity. The new cargo management system, with side rails featuring dual tracks and 500-lb. load points, offers many combinations of storage boxes and racks. The spring-mounted liftgate is also easy on the wrists, making loading and unloading a breeze.

Testing on the Track: Performance Confirmed

The next day at GM’s Proving Grounds in Mesa, we tested the trucks on a slalom course. This confirmed my earlier impressions of the GMT900 platform’s superior suspension and handling. I took the cones tight with no fishtailing and only a hint of tire squeal.

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

Lighter and More Powerful

Somehow, GM managed to give these trucks more interior room, bigger engines, better suspension, and more payload and towing capacity while making them 200 lbs. lighter than the previous generation. Kudos to GM for raising the bar once again.

By the time you read this, the new 2007 Chevy Silverado and GMC Sierra will have already hit the showrooms.