GM has released the 2015 Chevrolet Silverado and GMC Sierra HD lineup. The vehicles feature a number of updates over the previous model, including higher payload and towing capacities and alternative-fuel options.

Silverado 2500HD and 3500HD Models

Silverado 2500HD and 3500HD models available in Work Truck (WT), LT and LTZ trims, and are offered in regular cab, double cab and crew cab configurations (regular cab available only in WT and LT trims). The new double cab model replaces the previous extended cab and features forward-hinged rear doors, which allow easier access in tight parking spaces, according to the automaker.

The trucks are available with all-new, stronger 6-foot-6-inch and 8-foot cargo boxes with standard CornerStep bumpers, EZ Lift-and-Lower tailgates, and other features that make cargo handling easier, according to Chevrolet.

Additional updates for 2015 include:

• All-new exterior styling with enhanced cooling air flow, which enables Silverado’s 6.6-liter Duramax turbo diesel and 6.0-liter Vortec V-8 to better maintain full power, even under heavy loads and high ambient temperatures.

• All new cabs and interiors that provide increased space and comfort, with extensive storage space tailored to the way customers use full-size trucks.

• Chevrolet MyLink, which provides powerful connectivity for work or family with simple, intuitive controls.

• Integrated cruise control, auto grade braking and diesel exhaust braking (on diesel models) that help make tough towing easier.

• An expanded lineup of bi-fuel trucks that run on either gasoline or compressed natural gas (CNG).

• Standard StabiliTrak with Trailer Sway Control on all models including 3500HD duallys.

The 2015 Silverado HD will be available with a number of safety features such as forward collision alert, lane departure warning with an active safety seat, and front and rear park assist. Head-curtain and seat-mounted side airbags are standard on 2500 and available on 3500 models.

An available Z71 package on 2500HD and 3500HD includes Rancho monotube shocks (2500HD only), Hill Descent Control, underbody shields, brushed-metal Z71-logo door sill plates, Z71-logo gauge cluster, uniquely finished interior trim, unique lower front bumper appearance, unique grille with Z71 badge and Z71-logo cargo box graphics.

For 2015, CNG capability will be available on both 2500 and 3500 models in all three cab styles – regular, double and crew. As with previous bi-fuel Silverado models, the CNG fuel delivery and storage system is covered under GM’s limited warranty and is serviceable by Chevrolet dealers. Plus, all components have GM service part numbers for broad availability, providing customers with peace of mind that parts will be available to keep their vehicles on the road, according to the automaker.

The new truck cab is stronger, as well, with nearly two-thirds of the cab structure made from high-strength steel for a confident feel and improved safety, according to the automaker. The foundation of the 2015 Silverado HD lineup is a family of fully boxed frames, which use large cross sections, hydroforming, and high-strength steels in key areas. The stiffness of the frames contributes to improved handling and ride comfort, while the strength of the frames enhances payload and towing capability.

The Silverado HDs employ an independent front suspension specifically engineered for HD pickup use. Torsion bars tailored to the weight ratings of the trucks, allow easier trim height adjustment to account for the weight of snowplows or other accessories. In the rear, asymmetrical leaf springs balance ride and load carrying, and improve control of axle hop.

The sturdy chassis and heavy-duty suspensions contribute to greater payload and towing capabilities, compared to previous models:

• Maximum available payload is a segment-best 7,374 pounds, up from 7,222 pounds

• .Maximum available conventional towing is also segment leading, at 19,600 pounds with the available factory hitch – up from 18,000 pounds.

• Maximum available fifth-wheel towing is 23,200 pounds, up from 22,500 pounds.

The new Silverado HDs are engineered to bring new levels of confidence to tough towing through further refinement of Silverado’s available cruise control, auto grade braking, and diesel exhaust brake, according to Chevrolet. The integration of these features helps the 2015 Silverado HD maintain a set speed up and down grades, even when towing a heavy trailer in mountainous terrain.

On Duramax diesel models, the driver can also engage the diesel exhaust brake, which uses the variable vanes in the turbocharger to smoothly and quietly create additional backpressure in the engine to help slow the vehicle. The combination of the exhaust brake and the automatic transmission downshifts helps the driver maintain the desired speed, even on long, steep highway downgrades.

StabiliTrak with Trailer Sway Control is now standard on all Silverado HDs, including 3500 dually models, providing additional security to the drive.
The 2015 Silverado HD offers three powertrains specifically tailored for tough tasks and dependable service. The standard engine is a 6.0L FlexFuel V-8 with continuously variable valve timing, which is rated at 360 hp and 380 lb.-ft. of torque – and tuned to deliver excellent low-rpm torque. It’s matched with a six-speed automatic transmission.

A bi-fuel version of the 6.0L V-8 is now offered on 2500 and 3500 models in all three cab styles. The system enables customers to switch easily between gasoline and compressed natural gas.

The proven Duramax 6.6L turbodiesel and Allison 1000 six-speed automatic transmission combination will continue to be available on 2500HD and 3500HD models. Rated at 397 horsepower and 765 lb.-ft. of torque, it features piezo-actuated fuel injectors for improved performance and efficiency, and a variable vane turbocharger that also acts as an exhaust brake to help control vehicle speed when needed on long downgrades.

The Allison 1000 transmission features a driver shift control with tap up/tap down shifting and a Tow/Haul mode that reduces shift cycling for better control and improved cooling when towing or hauling heavy loads, according to the automaker.

Sierra 2500HD and 3500HD Models

Sierra 2500HD and 3500HD models – including Sierra Denali HD –are offered with the Duramax 6.6L turbo-diesel engine all Allison 1000 six-speed transmission powertrain combination.

Trim levels include a Sierra base model, as well as SLE, SLT and Denali. The distinctive Sierra Denali HD, which accounts for more than one-third of Sierra HD crew cab sales, is offered exclusively as a crew cab, matching do-it-all capability with an exclusive package of design and upscale interior amenities, according to the automaker.

Regular, double cab and crew cab models are offered across the lineup. 2500HD and 3500HD regular cab models are matched an 8-foot box, while 2500HD double cab and crew cab models are available with 6-foot-6-inch or 8-foot boxes. Sierra 3500HD double cab is offered exclusively with the 8’ box, while 3500HD crew cabs are available with the 6-foot-6-inch and 8-foot boxes. Dual-rear-wheel configurations are also available on 3500HD.

Gasoline and Duramax diesel powertrains are offered across the lineup, including an expanded bi-fuel option that allows the gas engine to run on compressed natural gas (CNG). The Duramax has been developed to operate for at least 200,000 miles on a rough-duty cycle without the need for a major overhaul.

The powertrains contribute to the new Sierra HDs’ greater payload and towing ratings than previous models, including the segment’s highest payload – 7,374 pounds – and the highest conventional trailering rating – 19,600 pounds. The maximum fifth-wheel/gooseneck trailering rating increases to 23,200 pounds.

Additional new and enhanced features for the 2015 Sierra HD lineup include:

• Standard CornerStep rear bumper, EZ Lift and Lower tailgate (standard on SLE, SLT and Denali), standard locking tailgate, standard upper tie-downs and other features that make cargo handling easier.

• Standard StabiliTrak with Trailer Sway Control on all models, including 3500HD dually.

• Integrated cruise control, auto grade braking and diesel exhaust braking, for greater driving control and reduced brake wear on grades.

• Enhanced cooling airflow, which enables the Duramax turbo diesel and 6.0L gas engine to better maintain full power, even under heavy loads and high ambient temperatures.

New 6-foot-6-inch and 8-foot boxes are stronger and more durable, easier to use and offer greater cargo flexibility, according to GMC. They come with a two-tier loading design and offer more than four feet of loading space between the wheel houses, allowing standard 4-foot x 8-foot sheets of plywood to stack flatly on the box floor.

The new CornerStep rear bumper – also introduced on Sierra 1500 – is standard. It features integrated steps at each corner designed to accommodate large boots, with textured pads for sure-footed grip. The EZ Lift-and-Lower tailgate is standard on SLE, SLT and Denali models, along with LED cargo box lighting. A factory-installed spray-in bed liner is available.

All Sierra HD models feature fully boxed frame assemblies – 18 different assemblies that accommodate more than 150 possible vehicle configurations across the lineup.

A short-long arm/torsion bar front suspension features forged steel upper control arms and precision-machined cast iron lower control arms. Five different torsion bar rates support five different front gross axle weight ratings to help stabilize the range of trim heights of various models under load – including snow plows – while enhancing appearance, handling, durability, tire wear and alignment.

At the rear, an asymmetrical leaf-spring design minimizes axle hop and enhances traction control efficiency. A two-stage leaf-spring design is used on 2500HD models and three-stage design is employed on 3500HD model.

Sierra HD’s advanced vehicle control technologies are designed to make tough jobs easier and more comfortable, while also contributing to a safe driving experience, particularly when hauling cargo or towing a trailer.
StabiliTrak electronic stability control is standard on all single-rear-wheel models and – new for 2015 – 3500HD dual-rear-wheel models. It incorporates trailer sway control and hill start assist. Additionally, available cruise control, auto grade braking, and diesel exhaust brake features help the vehicle maintain a set speed up and down grades, even when towing a heavy trailer.

With the diesel exhaust brake feature, the turbocharger is used to smoothly and quietly create additional backpressure in the engine to help slow the vehicle. The combination of the exhaust brake and the automatic transmission downshifts helps the driver maintain the desired speed, even on steep grades.

A rear-vision camera system is standard on SLE, SLT and Denali, providing a view of items behind the vehicle. It can also assist with lining up in front of a trailer.