Diesel Power
Mobile Icon BtnMobile Icon Btn RO
Newsletter

2015 Chevrolet Silverado HD/GMC Sierra HD First Drive

The General Completes The Package

Text By , Photography by Courtesy of General Motors

When General Motors last overhauled the Chevrolet Silverado HD and GMC Sierra HD chassis in 2011, we joked that they became some of the best trucks no one knew about. The reason for this was that the aging body and interior remained identical to the old trucks, falling behind that of the competition, while the foundation had some of the best bits in the business. With the 2015 model year, all that will change as the robust chassis finally gets the worthy interior and styling it’s been waiting for.

To allow us to become better acquainted with these new trucks, Chevy and GMC invited us out to Arizona to see them firsthand. We were also offered the option of taking the new HDs, as well as competing trucks, out on various drive loops, with and without a load, to a get a feel for how the trucks perform in the real world.

The familiar chassis remains basically untouched for 2015 and utilizes the only independent front suspension setup in the heavy-duty market. With torsion bars up front and the asymmetrical leaf springs out back, there aren’t any surprises with the Silverado and Sierra’s layouts. All HDs receive a short-long arm front suspension with forged steel upper and cast-iron lower arms for exceptional durability. No air springs are available, but to maintain ride quality, a two-stage rear leaf setup is used on 2500s, while 3500s benefit from a three-stage design. The only major difference to the fully boxed and hydroformed frame is the more extensive use of high-strength steel in strategic areas.

Also untouched for the 2015 model year is the 6.6L LML Duramax V-8. Still mated to a six-speed Allison transmission, the Duramax continues to be rated at 397 hp and 765 lb-ft of torque, numbers that -- at least on paper -- fall short of the competition. However, representatives from each respective GM brand will be quick to point out the trucks are driven in the real world (not on spec sheets) and they feel they put as much, or more, usable power to the road as any truck, allaying any fears that Chevy or GMC fans will be left behind by their Ford- or Ram-driving counterparts.

They make a valid point, as the GM twins sport the segment’s best 7,374 pounds of max payload capacity and the highest conventional tow rating of The Big Three at 19,600 pounds. Only the fifth-wheel numbers fall short, maxing out at 22,500 pounds -- far below Ram’s 30,000-pound model.

Where Chevy and GMC really upped the ante, though, is with all-new styling and interiors that mirror the upgrades given to the 2014 ½-tons. The new truck cabins are as impressive and technologically advanced as anything on the market.

High-strength steel is now used in about two-thirds of the body structure, improving strength and lessening unwanted noise, a major focus during development. With engineers working hard on a quiet driving experience, the trucks have been tuned in the wind tunnel to improve aerodynamic efficiency and decrease wind noise. The results are a new body that has inlaid and triple-sealed doors and one of the quietest cabins available today. The improved airflow allows for better thermal management of the powertrain and lets the Duramax maintain full power, even under load and at altitude.

Even the cargo boxes, which are available in either a 6-foot, 6-inch or 8-foot length, have been improved and strengthened. Similar to the beds on the ½-ton Silverado and Sierras, the boxes feature two-tier loading capability, integrated tie-downs, and an optional EZ Lift-and-Lower tailgate. Access to the bed has been improved with the addition of a CornerStep rear bumper.

Beyond the new styling and body improvements, the cabs are available in regular, double (replacing the extended cab and now featuring forward-hinged doors), and traditional crew. The rear doors are longer and, thanks to revised seats, the back seating positions now have an additional 2 inches of rear legroom. Front seat occupants are rewarded with a well-laid-out instrument panel shared with the ½-ton trucks. A six-gauge cluster and driver information center report vital information to the driver, while a new 8-inch touch screen brings a level of user friendliness to the onboard technology never imagined with the old system.

Speaking of technology, the Silverado and Sierra are packed full of it. A fully kitted truck will net you easy-to-use navigation, MyLink (Chevy) or IntelliLink (GMC), 4G LTE connectivity with WiFi hot spot functionality, and a host of ports and power outlets that would put your desktop to shame. For example, the center console houses a large storage cubby (one of many) with a 110-volt outlet, five USB ports, and an SD card slot. No one will be fighting over charging ports in this truck.

Whether you walk into the Chevy or GMC dealer, you’ll have the choice of more than 150 configurations of the new truck, as well as multiple trim levels. On the Chevrolet side, trim levels include Work Truck (WT), LT, and LTZ, while GMC customers get to choose from SLE, SLT, and Denali. An available Z71 off-road package includes Rancho monotube shocks, Hill Descent Control, skidplates, unique interior and exterior trim, and an optional rear locker.

All these upgrades result in a competitive, capable, and refined truck, as evidenced by our time behind the wheel. During our drive, we found the Silverado and Sierra to be as competitive as anything in the segment, and the new styling and interior bring the models full circle. As expected, the Duramax is fantastically responsive, the chassis is stable (with or without a load), and the brakes offer a firm pedal with very good feedback to the driver. The whole package inspires confidence -- especially when towing.

The highlight of our short drive was testing the Silverado and Sierra’s integrated cruise control system, which combines the cruise control, auto grade braking, and diesel exhaust braking into one highly proficient function. With a 10,000-pound trailer attached, we attempted several long grades with the exhaust brake on and cruise control set at a specific speed. Unlike the competition, which required some manual gear selection and/or braking to maintain close to a preset speed, GM’s integrated cruise control seamlessly maintains the exact pre-selected speed without any driver intervention at all. Integrated cruise control is an industry exclusive and is just one more way the Silverado and Sierra maintain trust with a load hanging off the back.

For those Chevy and GMC fans who have been holding out for an update, we think you’ll find the new trucks will exceed your expectations. With a new look and tons of new features, GM can once again be proud that the company has trucks that can go toe to toe with the competition. In fact, we have plans in the works to revisit our King of the Hill shootout later this year, and see just how well these new HDs match up to their cross-town rivals in the real world.


2015 Chevrolet Silverado 3500HD Crew Cab 4x4 SRW
Base price: $60,000 (est.)
Engine type: 6.6L 90-degree V-8
Valvetrain: OHV, four valves per cylinder
Aspiration: Variable-geometry turbocharger, air-to-air intercooler
Mfg. hp at rpm: 397 hp at 3,000 rpm (est.)
Mfg. torque at rpm: 765 lb-ft at 1,600 rpm (est.)
Transmission: Six-speed Allison 1000
Axle ratio: 3.73:1
Suspension (f/r): SLA IFS, torsion bars/Live axle with three-stage asymmetrical leaf springs
Steering: Power-assisted recirculating ball
Brakes (f/r): 13.98-inch vented disc/ 14.17-inch vented disc
Wheels/Tires: 20x8.5-inch aluminum/ LT265/60R20 all-terriain
Curb weight: 7,500 pounds (est.)
Max payload capacity: 2,793 pounds (est.)
Max towing capacity:17,100 pounds (est.)

Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
Diesel Power