2007 Chevrolet Silverado/GMC Sierra in Detail

2007 Chevrolet Silverado

With all-new and differentiated exterior designs

By Text & Photos edited by Clinton Deacon
October 2, 2006 6:08 AM
Filed Under: American, Chevrolet

Press Release

Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Overview (I)

Strong exterior designs:

Spacious and functional interiors:

Exceptional driving experience:

Comprehensive safety and security:

Unique features and options:

General Motors introduces the new 2007 Chevrolet Silverado and GMC Sierra heavy-duty pickups, with all-new and differentiated exterior designs, two unique interiors and class-leading power and efficiency. The redesigned pickups incorporate brand-distinct exterior and interior designs that are greatly differentiated from the light-duty trucks, along with a choice of gas and diesel powertrains. Capabilities are enhanced and complement new, segment-leading and segment-exclusive features.

Silverado and Sierra are offered in a range of 2500HD (three-quarter-ton) and 3500HD (one-ton) models, reaffirming GM's nearly 100-year legacy of building heavy-duty trucks. The 2007 models offer unprecedented levels of performance, capability and refinement. Silverado is available in WT, LT and LTZ trim; Sierra is available in WT, SLE and SLT trim - all with differentiated appearance and interiors.

"There's not a broader, more powerful or more capable lineup of heavy-duty pickups in the industry," said Gary White, GM North America vice president and vehicle line executive of full-size trucks. "But along with the capability and functionality that our customers expect, the 2007 Silverado and Sierra heavy-duty trucks meld exceptional refinement and surprising attention to detail."

The range of configurations - three cab styles, three cargo box styles and five wheelbase lengths - delivers tremendous choice. Some full-size truck manufacturers do not even offer three-quarter-ton or one-ton heavy-duty trucks. And among those that do, the 2007 Silverado and Sierra HD pickups offer many segment-best capabilities, including 18,500-pound (8,392 kg) gross combined vehicle weight rating for vehicles with a gas V-8 and a 13,000-pound (5,897 kg) conventional trailer weight rating enabled by a larger-capacity trailer hitch platform. Maximum towing capacity is 16,700 pounds (7,575 kg), when equipped with a fifth-wheel hitch.

"GM's heavy-duty pickup heritage is built on the promises of function and dependability," said White. "The new Silverado HD and Sierra HD trucks offer exceptional capability, while building on the reputation that has put GM full-size pickups at the top of numerous quality surveys."

Chevy Silverado and GMC Sierra 2500HD and 3500HD models will arrive in the first quarter of 2007. Production of the new trucks is shared among several assembly plants, including Fort Wayne , Ind. , and Pontiac and Flint , Mich.

Bold and distinctive exterior designs

The new Silverado and Sierra heavy-duty models have bolder, muscular designs that are differentiated from their light-duty siblings. This includes new grilles, headlamps, hoods and front fenders - all conveying broad-shouldered, ready-for-anything strength. The trucks also feature more distinct brand differentiation than any previous generation.

Chevy Silverado has a wider and taller dual-port grille, with a prominent gold bow tie emblem at the center. Large, reflector-optic headlamps and corner lights wrap around the front end and flow into flared front fenders, enhancing the truck's broad stance. The fender flares have a chiseled, squared-off appearance and complement the strong power dome hood design.

GMC Sierra has a distinctive front end with a prominent GMC emblem set in a large, chrome-ringed grille (black grille surround on work truck models). The grille is flanked by large, jeweled-appearance headlamps. Chrome bumpers with body-color top and end caps are standard. SLE models feature large foglamps set into the bumper, creating an upscale appearance that further reflects GMC's brand identity.

The trucks' door handles feature large, grab-style designs that are easy to open with gloves. Other details also enhance the strong appearance and functionality includes larger front recovery hooks. A faster, 57-degree windshield angle reduces wind noise and improves fuel efficiency.

The trucks are more refined looking, too, with doors that extend over the rockers for a smooth, uninterrupted look, and lamps that have a jeweled appearance. Tolerances between panels are greatly reduced - including a 50-percent reduction in the space between the cab and cargo box.

Cab and cargo box configurations

Silverado and Sierra heavy-duty trucks are offered in regular, extended and crew cab configurations, which are complemented with standard (6-foot 6-inch) and long (8-foot) cargo box lengths. Silverado and Sierra 3500HD models also are available with the Dually dual rear wheel configuration on a long (8-foot) box. New features, such as 170-degree-opening rear access doors with fully retractable power windows on extended cab models, offer increased versatility.

The pickup boxes have been redesigned with enhanced versatility, increased strength and greater capacity. A one-piece wheelhouse and inner box side add strength and a smoother, more integrated appearance. The boxes are 1.18 inches (30 mm) deeper in the front and 1.57 inches (40 mm) deeper at the rear, with stronger inner walls that offer improved performance when fitted with ladder racks, tool boxes and other accessories. Cargo bed volume is 60.7 cubic feet (1,718 L) with the regular box and 75.5 cubic feet (2,138 L) with the long box.

Dually cargo boxes are made of all steel, including new, hydroformed sheet metal outer fenders. They have a smooth, integrated appearance and enhanced strength. All Dually models feature marker lights on the fenders and new, sleek cab roof lights that are aerodynamically integrated into the top of the cab.

New tailgate designs include a lock and an available EZ Lift feature, with torque-rod assist. Despite being larger than previous models, the new tailgates are easier to use, thanks to revised construction that reduces overall mass. The tailgates are easily removed by simply opening to 45 degrees and pulling straight out and away from the vehicle.

A new, innovative cargo management system is available on all Silverado and Sierra models and is complemented by a range of dealer-ordered accessory packages. Three rails that run the length of the box sides and the forward box wall are secured with high-strength anchors and, unlike competitors' systems, incorporate upper and lower tracks. Four adjustable tie-down brackets are included with each system and can be located anywhere on the tracks, each rated for a load point of 500 pounds (227 kg).

At the heart of a comprehensive accessories portfolio for the new pickups is a group of specific accessory products designed to integrate into the cargo management system. The rails enable the use of an overhead utility rack rated at 500 pounds (227 kg) loading capacity, a sliding diamond plate toolbox, a sliding bed divider, diamond plate side storage boxes or a bicycle mount. These accessories use either the upper or lower rails, allowing numerous combinations that can easily fit together or bypass one another as they slide along the rails. The tool boxes and bicycle mount use a codeable lock, enabling the vehicle key to be used for locking and unlocking these accessories.

Segment-leading interior designs with superior craftsmanship

Chevy Silverado and GMC Sierra HD pickups are quieter, more spacious and refined inside, with increased passenger comfort and storage space. They each feature two new and distinct interior designs that reflect their respective brand identities, including specific trim, appointments and gauge cluster appearance.

Silverado and Sierra HD base and midlevel trim models include a functional pure pickup interior design theme with a contemporary adaptation of GM's ergonomic cockpit instrument panel design. In addition, this interior includes specific door panels with large door pull and release handles, new seat construction and configurations, unique center console and underseat storage systems, and two glove boxes (a traditional lower glove box and a covered upper storage compartment).

New luxury-inspired premium interiors are standard on Silverado LTZ and Sierra SLT. They offer richly appointed features, including a distinct instrument panel design, large-capacity center console (20.1 L), specific door panels, seats and other trim elements. Features on the premium interiors include power-adjustable heated bucket seats, leather surface seats, leather-covered steering wheel and selective chrome trim.

Spaciousness in each interior trim level is enhanced with new, "low and forward" instrument panels that provide a more airy feel to the cabin as well as a panoramic field of vision. The instrument panels are mounted approximately 3.5 inches (90 mm) down and forward on the pure pickup interiors, while the premium interior instrument panel is located 5 inches (127 mm) down and forward. Both instrument panel designs are integrated into their specific door panels to create a swept appearance.

The spacious interior and enhanced field of vision create an environment that enables better outward vision. Legroom, headroom and hip room also have increased. The recline angle and fore/aft travel of the front seat have been increased.

All interiors are refined and craftsmanship is highlighted by flush surfaces, tight gaps and tolerances on the instrument panel, center stack, clusters and other components. Most gaps on the instrument panels and clusters have been narrowed to 0.5 mm or less. Attention to detail was given to concealing fasteners and metal structural components of all seats. There is no exposed hardware in the interior or door sills. New, soft-touch and low-gloss finishes for the instrument panels and other trim pieces are used throughout. The color and grain of the materials were carefully selected to provide a premium look. Sculpted headliners of new woven fabric and door trim, as well as sculpted seat backs, enhance the perception of precision in the new interiors.

Complementing the interiors' finely crafted look and feel is segment-leading quietness. All trim levels - even base work truck models - benefit from a comprehensive system that delivers a passenger environment almost devoid of noise. This is achieved with the use of strategically placed sound-deadening and sound-absorbing material in the body structure - including liquid-applied dampener on the floor and front-of-dash - as well as the inherent, vibration-minimizing traits of the stiffer frame and quieter attributes of the aerodynamically tuned exterior. Also, improved door sealing and a doors-over-rockers design help eliminate road and wind noise.

Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Overview (II)

Additional highlights of Chevy Silverado and GMC Sierra interiors include:

Driving experience and capability

A new, Gen-IV 6.0L gasoline V-8 engine with variable valve timing and an enhanced, more powerful version of the Duramax 6.6L turbo-diesel are the engine choices for the Silverado and Sierra 2500HD and 3500HD models. Both engines offer segment-leading power and torque ratings. The gas engine is backed by a new, Hydra-Matic 6L90 six-speed automatic transmission, which features grade braking capability. Duramax-powered trucks are backed by the reknown six-speed Allison 1000 automatic transmission.

The standard engine is the new, 6.0L gas V-8. It is rated at a best-in-class 353 horsepower (233 kW) and 373 lb.-ft. of torque (506 Nm) on single rear wheel configurations.* Variable valve timing helps improve performance and fuel economy. A new, Hydra-Matic 6L90 six-speed automatic transmission is paired with the engine. This powertrain combination offers a higher maximum gross combined weight rating (GCWR) – 18,500 pounds (8,392 kg) – than previous gas-powered combinations and is the segment leader for vehicles with a small-block V-8 gas engine. The 6L90 has a wide, 6.04:1 overall ratio – including two overdrive gears – that helps deliver an excellent balance of performance and fuel economy. It also offers manual range selection and tap up/tap down control.

A cleaner, more powerful Duramax 6.6L turbo-diesel engine is available. It continues to lead the segment in power and torque, with power ratings increased to 365 horsepower (272 kW) and 660 lb.-ft. of torque (895 Nm). Upgrades to the engine and a new diesel particulate filter system help provide a 90-percent reduction in particulate matter and a 50-percent reduction in NOx (compared with current standards), meeting a new federal government mandate. All diesel manufacturers are required to meet the new emissions standard, starting in calendar year 2007.

The renowned Allison 1000 six-speed automatic transmission is partnered with the Duramax 6.6L turbo-diesel engine. It delivers good fuel economy, quietness and control. It features a class-first range selection function, which allows the driver to easily select the desired gears to match driving conditions, such as towing a trailer on a steep grade.

Working in concert with the powertrains are a strong chassis and responsive suspension systems. The vehicle frame is comprised of a sturdy ladder design that is reinforced with cross braces. It features a segmented design that enables easy and accurate adaptation of numerous lengths to accommodate the trucks’ five wheelbase lengths. The frame sections are joined with strong, overlapping segments that bolster overall strength and rigidity.

The strength of the frame and enhanced capabilities enabled by the powertrain systems allow the 2007 Silverado and Sierra heavy-duty trucks to offer a larger, 2.5-inch trailer hitch receiver platform. This enables the trucks to pull a segment-leading maximum of 13,000 pounds (5,897 kg) with conventional trailers. Trucks with fifth-wheel hitches can tow up to 16,700 pounds (7,575 kg), when properly equipped.

Additional features:

All heavy-duty models are available with an integrated trailer brake controller. It is integrated with the ABS system and provides immediate and measured brake force signaling to electric-controlled trailer brake systems. There is no requirement for external and/or aftermarket brake control systems. The brake controller switch is conveniently mounted on the lower-left section of the instrument panel.

Safety details

Silverado and Sierra heavy-duty models are designed to help drivers avoid crashes and protect passengers in the event one occurs. The robust ladder frame and strong body structure provide occupant protection. The frame is designed with crush zones that crumple to absorb crash energy, while the new body structure incorporates the strategic use of high-strength steel and structural adhesives designed to help maintain passenger compartment integrity and manage energy in a crash.

Additional safety features include:

All retail models come standard with the OnStar Generation 7 system, including a one-year subscription to the Safe & Sound plan. The OnStar service includes the General Motors Advanced Automatic Crash Notification (AACN) system, making crash data available to emergency services to potentially dispatch the appropriate life-saving personnel and equipment to crash scenes faster. If the vehicle is in a crash that activates an air bag, the OnStar system automatically notifies an OnStar advisor, who will check on the occupants or summon emergency help if necessary. OnStar also can assist authorities in locating a vehicle if it is reported stolen and provides remote door-unlocking service (when the vehicle is equipped with power locks).

*SAE certification. A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005. This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing. GM was the first auto manufacturer to begin using the procedure and expects to use it for all newly rated engines in the future.


Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Chassis

Designed to pull their weight for any task while simultaneously delivering a smooth, responsive ride, 2007 Chevy Silverado and GMC Sierra heavy-duty chassis and suspension systems are enhanced to support the trucks’ increased capabilities, including segment-leading maximum conventional trailer weight rating (13,000 pounds / 5,897 kg) and gross combined vehicle weight rating (18,500 pounds / 8,393 kg). Enhancements include revised suspension tuning and a new steering gear. New 17-inch aluminum wheels and tires also are available.

“Silverado and Sierra heavy-duty pickups are known for their balance of great ride and handling while performing under load,� said Jim Mikulec, vehicle performance manager. “The new 2007 models build on that reputation with refinements that bolster driver control and enhancements that support their increased capabilities.�

In addition to their greater capabilities, the heavy-duty trucks are offered with an integrated trailer brake controller that eliminates the need for add-on brake controller systems.

Robust frame

Serving as the backbone of the Silverado and Sierra heavy-duty pickups’ strength and capability, the vehicle frame is comprised of a sturdy ladder design that is reinforced with numerous cross braces. It features a segmented design that enables easy and accurate adaptation of numerous lengths to accommodate the trucks’ five wheelbase lengths. The frame sections are joined with strong, welded, overlapping segments that bolster overall strength and rigidity. There are five wheelbase lengths to accommodate the trucks’ broad range of configurations.

The front frame section is constructed of hydroformed side rails; GM pioneered the use of hydroformed frame rails for full-size trucks on the previous-generation vehicles. The process uses highly pressurized fluid – up to 20,000 psi – to shape the frame rails. This provides a strong, more accurate frame section that enables very precise location of suspension components.

The midsection of the frame features a ladder-type design, with strengthening cross braces. The midsection retains the basic configuration of previous models, with minor revisions to accommodate new body mounts and diesel particulate filter equipment. The rear frame section supports the rear leaf spring suspension, axle and trailer hitch platform and, like the midsection, it features strategic cross braces for strength and stiffness.

Integrated trailer brake controller

New Silverado and Sierra heavy-duty trucks are now available with an integrated trailer brake controller. It is integrated with the ABS system and provides immediate and measured brake force signaling to electric-controlled trailer brake systems. As it is fully integrated with the vehicle’s ABS and electric systems, there is no requirement for external and/or aftermarket brake control systems – response is simultaneous with the application of the vehicle brakes. The trailer brake controller switch is located at the lower-left of the instrument panel.

“This is a feature anyone who tows a trailer will really appreciate,� said Mikulec. “There’s no need to have an aftermarket system wired up – this factory-installed system does it all within the vehicle’s new electrical architecture.�

Increased capacity tow hitch receiver

To maximize the towing capacity of the 2007 Silverado and Sierra heavy-duty pickups, the tow hitch platform is upgraded and features a 2.5-inch receiver, versus the previous two-inch design. This enables a higher-capacity tow hitch to be used and increases the maximum conventional trailer weight to a segment-best 13,000 pounds (5,897 kg). The hitch receiver platform is mounted directly to the vehicle frame.

The increased-capacity hitch platform complements the gross combined weight rating (GCWR) of 18,500 (8,392) pounds for both gas- and diesel-powered vehicles – a segment-best for small-block gas-powered heavy-duty trucks.

Suspension systems

The front suspension for all Silverado and Sierra heavy-duty models uses an independent short-long arm ( SLA ) design with torsion bars. Shock absorber valving is tuned to balance smooth, compliant ride and handling traits whether the truck is loaded or empty. A Hotchkiss-type live axle rear suspension features a robust rear axle design and two- or three-stage multi-leaf springs that support the vehicles’ towing and payload capabilities.

There are two suspension packages available: Z85 and Z71. The Z85 suspension is standard on 2WD and 4WD models; the optional Z71 Off Road suspension is new on 2007 heavy-duty models and includes additional chassis and suspension equipment, including skid plates.

All Silverado and Sierra heavy-duty models ride on a wide, 68.6-inch (1,742 mm) front track. The rear track on 2500HD trucks is 66 inches (1,676 mm); the rear track on 3500HD is 74.7 inches (1,897 mm). The wide track widths give Silverado and Sierra heavy-duty models a firmly planted feel and contribute to their smooth, responsive ride and handling.

Steering details

A new steering control box is used with the recirculating ball steering system on all heavy-duty models, delivering improved returnability for a greater feeling of control and on-center feel. The steering ratio remains at 24:1.

The new steering gear also is lighter in weight than the previous steering box. Power-assisted steering is standard on all models.

Large-capacity brake system

A high-capacity, four-wheel disc brake system with four-wheel ABS provides Silverado and Sierra heavy-duty trucks with superior stopping capability. ABS is standard on all models. The brake system includes large-diameter front and rear disc rotors and stiff brake calipers.

The front rotors are thick, with large cooling vents, and are acted upon with stiff, cast iron, dual-piston brake calipers. The calipers reduce the tendency for flexing during hard or prolonged braking and, with the large rotors, contribute to a direct and strong brake pedal feel. The rear disc brakes feature standard vented discs and a single-piston rear brake caliper design that contributes to reduced brake noise and more immediate braking response.

The brakes are complemented by the Hydroboost brake application system, including a larger master cylinder and active brake booster. Engineers tuned the application system to optimize pedal feel and system responsiveness. Less pedal pressure is required to provide a more immediate brake response.

Wheels and tires

New 17-inch tires and aluminum wheels are available on the heavy-duty models. They complement the standard 16-inch wheel-and-tire combinations on single rear wheel models. Sixteen-inch steel wheels are standard; 16-inch aluminum wheels are available. Models equipped with the Z71 Off Road package come with 17-inch aluminum wheels. All Dually models are offered with 16-inch wheels.

All models are available with either all-season tires or all-terrain tires. Sixteen-inch tires are sized at 245/75R16; the 17-inch tire size is 265/70R17.


Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Design

With the capabilities to back up their chiseled good looks, the 2007 Chevy Silverado and GMC Sierra 2500HD and 3500HD heavy-duty trucks convey strength from every angle. Silverado and Sierra each have distinct designs, rooted in the functionality demanded of heavy-duty trucks. They also deliver a significant increase in fit, finish and refinement.

Distinct design differentiation, including unique sheet metal, separate Chevy and GMC models and reflect their respective brand philosophies. The heavy-duty models also are substantially differentiated from their light-duty siblings, with bolder grilles, taller hoods and brawnier front-end sheet metal. As with the light-duty models, the 2007 Silverado and Sierra heavy-duty trucks’ larger grilles are flanked by prominent headlamps and reflect the functional ethic of the trucks, as the grilles enable increased cooling.

“Heavy-duty trucks are first and foremost about capability, and the new Silverado and Sierra don’t sacrifice function for form,� said John Cafaro, design director for full-size trucks. “These trucks meld high refinement and precision with a strong, broad-shouldered design that commands respect.�

As with the ’07 Silverado and Sierra light-duty trucks, the heavy-duty trucks are sleeker and more aerodynamic, including a faster, 57-degree windshield angle. This helps reduce wind noise and improve fuel economy despite a larger frontal area. The trucks are more refined looking, too, with doors that extend over the rockers for a smooth, uninterrupted look, and lamps that have a jeweled appearance. Tolerances between panels are greatly reduced – including a 50-percent reduction in the space between the cab and cargo box.

The trucks are offered with three cab designs – regular, extended and crew cab – and four cargo boxes, including standard (6-foot 6-inch) and long (8-foot); and Dually standard (6-foot 6-inch) and Dually long (8-foot) lengths. New features, such as 170-degree-opening rear access doors with fully retractable power windows on extended cab models, offer increased versatility. The new rear fenders on Dually models use hydroformed sheet metal technology, providing a sleek, integrated appearance and enhanced strength.

Also, a host of new and improved features are woven into the Silverado HD and Sierra HD, including improved lighting – with sleeker, integrated roof lamps on Dually models – a stronger cargo box with more cargo capacity and reduced-effort tailgates. An innovative cargo management system is available with a diverse range of work and lifestyle accessories, giving the trucks unmatched capability for any task.

Silverado design

Silverado 2500HD and 3500HD designs reflect Chevy’s heritage as the industry’s toughest, most dependable and longest-lasting truck. It features a large, wide dual-port grille with chrome surrounds and a prominent gold Chevy bow tie emblem. The width conveys a broad-shouldered stance, which is enhanced by prominent, vertically stacked headlamps – with reflector optics – and corner lamps that wrap tightly around the front corners.

The Silverado also features a large, distinctive wraparound front bumper, which is accented in chrome on LS and LT models; the bumper is body-color on LTZ models. The grille, lighting elements and bumper flow into flared front fenders that give the truck a decidedly powerful and muscular stance. And while the front fenders flare outward, the signature power dome hood flares upward, suggesting the power generated beneath it.

The door handles are robust, grab-style designs, which are designed for easy use with gloves. The popular Z71 Off Road package is offered for the first time on heavy-duty models (single-rear wheel only) and features unique exterior appointments and body side identification. Silverado also offers larger front recovery hooks.

Silverado models are offered with a range of 16-inch and all-new 17-inch wheels. Seventeen-inch wheels are standard with the Z71 package.

Sierra design

GMC Sierra 2500HD and 3500HD are designed with a strong and refined appearance befitting the brand’s professional grade philosophy, including muscular character lines and rounded, precisely formed edges. The front end appearance, front fenders, bumpers, hood, grille, headlamps, taillamps and rear fenders are unique to the heavy-duty models. A “center-focused� hood is broader and taller, and flows outward to meet the front fenders. Those fenders are flared, enhancing the truck’s firmly planted stance.

A prominent GMC emblem set in a chrome-ringed grille (black grille surround on Work Truck models) is a brand hallmark. The grille is bolder and signals the vehicles’ more robust capabilities. The grille is also larger, promoting enhanced cooling to the Vortec 6.0L gas or Duramax 6.6L turbo-diesel engines. Additional cooling is available via inlets in the bumper. The grille is flanked by large, jeweled-appearance headlamps.

Chrome bumpers with body-color top and end caps are standard. SLE models feature large foglamps set into the bumper, creating an upscale appearance that further reflects GMC’s brand identity. All door handles feature large, grab-style designs that are easy to open with gloves. Other details also enhance the strong appearance and functionality of the Sierra, including larger front recovery hooks.

A family of 16- and all-new 17-inch aluminum wheels and tires is available.

Body structure and exterior details

The new heavy-duty trucks use a single-piece body side stamping and bolt-on door hinges, which foster significantly increased fit and finish. The single-piece stamping reduces production complexity, as multiple pieces of sheet metal are not required to be welded together to form the body side. The bolt-on hinges – rather than weld-on hinges – enable more accurate door-roof alignment. The new hinges and improved door sealing also help reduce door closing effort. Changes to the latch mechanisms also improve opening and closing efforts on the rear access doors of extended cab models.

Build precision is seen in the flush, virtually seamless transition between the hood and front fenders, along with very tight tolerances around the grille, fenders and front bumper. The hood-to-fender gap is targeted at 4 mm. The grille-to-bumper gap has been reduced to 17 mm and headlamp-to-fender gap is reduced to 1.5 mm. The accuracy of the body and tighter tolerances enhance aerodynamics.

Wind noise also is minimized with the trucks’ sleek shapes, which deliver best-in-class aerodynamics. Additional contributors to low wind noise include outside mirrors – including adjustable trailer mirrors – shaped in GM’s wind tunnel and new door seals. The primary door seal uses a sculpted shape with internal chambers and hinging, which allows the seal to collapse on itself for a tighter fit. An auxiliary door seal is attached to prevent movement or “walking� during driving, ensuring continuous contact with the door edge. Also, an improved windshield-to-roof seal contributes to interior quietness with a tighter fit between the windshield and the roof.

A fast, 57-degree windshield rake is a large contributor to the trucks’ aerodynamic proficiency. Other contributors include:

Rear access doors: The rear access doors on extended cab models open a wide 170 degrees, offering virtually unobstructed passenger and cargo loading. This feature is especially helpful in close areas, where side access is limited. The 170-degree opening is one of three stop detents in the hinge mechanism; the other two are at 60 degrees and 90 degrees. Fully retractable power windows are available on the 170-degree rear access doors, making the combination a segment exclusive for Silverado and Sierra.

Dually fenders and pickup box details

Silverado and Sierra heavy-duty models are offered with three pickup bed configurations: standard (6 foot 6 inches), long (8 foot) and Dually (8 foot). The Dually outer fenders are made of hydroformed sheet metal, for a smooth, integrated appearance and enhanced strength. Dually models also feature marker lights on the rear fenders and on the cab roof.

The pickup boxes have been redesigned with enhanced versatility, increased strength and greater capacity. A one-piece wheelhouse and inner box side adds strength and a smoother, more integrated appearance – it also eliminates the “pencil� lower fender support brace of previous models.

Cargo boxes are 1.18 inches (30 mm) deeper in the front and 1.57 inches (40 mm) deeper at the rear, with stronger inner walls that use a single steel panel instead of two welded pieces. The stronger boxes offer improved performance when fitted with ladder racks, tool boxes and other accessories. The new inner box panels also enabled a slight increase in bed width.

All models and box lengths come with a two-tier loading design, with pockets stamped into the inner side panels that are designed to accept several 2 x 8s across the width of the box. Provisions for bulkhead dividers also are built in.

New tailgates

New tailgate designs on Silverado HD and Sierra HD include a lock and an available EZ Lift feature, with torque-rod assist. Despite being larger than previous models, the new tailgates are easier to use, thanks to revised construction that reduces overall mass. The EZ Lift torque-rod assisted tailgate has a minimum effective weight of only 15.7 pounds (7.1 kg). The tailgates use welded-on hinges and stronger handle assemblies.

The tailgates are easily removed by simply opening to 45 degrees and pulling straight out and away from the vehicle. A standard end cap on each tailgate features an integrated spoiler lip that enhances aerodynamics.

Cargo management system

A new, innovative cargo management system is available on all Silverado and Sierra heavy-duty models, and it is complemented by a range of dealer-ordered accessory packages. Three rails that run the length of the box sides and the forward box wall are secured with high-strength anchors and, unlike competitors’ systems, incorporate upper and lower tracks. Four adjustable tie-down brackets are included with each system and can be located anywhere on the tracks. Each is rated for a load point of 500 pounds (227 kg).

At the heart of a comprehensive accessories portfolio for the new pickups is a group of specific accessory products designed to integrate into the cargo management system. The rails enable the use of an overhead utility rack rated at 500 pounds (227 kg) loading capacity, a sliding diamond plate tool box, a sliding bed divider, diamond plate side storage boxes or a bicycle mount. These accessories use either the upper or lower rails, allowing numerous combinations that can easily fit together or bypass one another as they slide along the rails. The tool boxes and bicycle mount use a codeable lock, enabling the vehicle key to be used for locking and unlocking the accessories.

The system provides moveable, high-strength tie-downs for the left- and right-hand sides of the pickup box, onto which a number of work and lifestyle accessories can be attached. Aluminum rails that run the length of box sides allow the use of a commercial overhead rack, sliding tool box, sliding bed divider, sliding side storage boxes or a locking bike mount. Tonneau covers also are available as accessories.

Lighting

Large, bright reflector-optics headlamps blend smoothly into the fenders. Clear lenses and bright metallic reflectors inside the headlamp housings provide a premium, jewel-like appearance. The headlamps have a “four-bulb burn� design, meaning the low beams remain illuminated when the high beams are turned on. Lighting performance is significantly improved over previous models.

Vertically arranged taillamps put out more light than previous models. They use three-cavity housings and premium-look lenses. Cargo area lighting also is improved, with lamps that throw more light than before. They are integrated into the CHMSL housing and designed to flood even the long bed with sufficient light to make nighttime work easier and safer.

Outside mirrors

Streamlined outside mirrors contribute to the trucks’ low wind noise and superior aerodynamics. Power-folding mirrors are available and offer heated glass to clear frost or ice. The power mirrors also have a curb feature that allows the glass to tilt down while the vehicle is reversing, allowing the driver to better judge the distance to the curb or other close objects. Also, in-glass turn signal repeaters operate in tandem with the front and rear signals.

Camper mirrors and trailer towing mirrors are available. Both styles offer extendable mounts and 60 square inches (3,871 sq mm) of glass area. The trailer towing mirrors add power-adjustable, heated glass and turn signal repeaters.

Flat-blade windshield wipers

Silverado and Sierra heavy-duty models use flat blade windshield wipers with unique wiper arms. The flat blade design offers improved glass clearing, providing more uniform pressure on the glass and virtually eliminating the chance for “chatter� due to impaired or frozen joints. The wiper arms are aerodynamically styled to reduce wind noise. Heated windshield washer fluid is available.

Roof rack

New for 2007, a roof rack is available on crew cab models and styled to provide an integrated appearance with the vehicle’s design. Cargo support cross bars are accessories available through dealerships.


Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Interior

The new 2007 Chevy Silverado and GMC Sierra 2500HD and 3500HD pickups have finely crafted, spacious interiors that establish new benchmarks in comfort, versatility and quietness. Two all-new interiors are available – a “pure pickup� interior and a luxury-inspired interior – each reflecting the growing diversity of today’s truck customers.

The new interiors have greater brand distinction, with each model highlighting characteristics that embody its brand – including different, luxury-inspired premium interiors with distinct instrument panels, door panels, console and appointments. All models have a high level of refinement and quality craftsmanship, which is evidenced with the use of premium materials, chrome accents and soft-touch surfaces with low gloss levels. Sculpted headliners and door panels, along with upscale instrument panel controls and gauges, convey a high degree of perceptual quality.

“Heavy-duty pickups have always doubled as rolling offices for many customers, and the new Silverado and Sierra HDs offer the most comfortable, well appointed ‘offices’ on the market,� said Gary White, General Motors North America vice president and vehicle line executive for full-size trucks. “Along with intuitive controls and useful features, the Silverado and Sierra interiors are quiet and refined, with exceptional attention to detail.�

Silverado and Sierra heavy-duty interior highlights:

Brand and model distinction:

Refinement and craftsmanship:

Spaciousness and comfort:

Storage versatility:

Convenience and functionality:

‘Pure pickup’ interiors

Standard on Silverado WT and LT, Sierra WT and SLE models is a highly functional pure pickup interior design that features a contemporary adaptation of GM’s ergonomic cockpit instrument panel. The driver’s cockpit has a gently sweeping arc, putting gauges, vents and controls within arm’s reach. Knobs and controls are larger and easily manipulated by gloved hands, while durable materials and rugged textures are used throughout. The unique instrument panel features an all-new “double� glove box that incorporates a conventional lower glove box, with a covered storage compartment above it.

Brand-unique six-gauge instrument clusters are standard, with the driver information center featuring readouts specific to heavy-duty models, including transmission temperature.

Specific door panel designs on the pure pickup interior include robust door pull handles and large release handles, which are designed for easier use with gloves. Details, such as bottle holders molded into the front door pockets, contribute to the trucks’ overall functionality and intuitiveness.

A new, 40/20/40-split front bench seat is available. It features a large, fold-down armrest console with integrated cupholders and 6.1 liters of storage. A new, locking underseat storage bin provides 9.1 liters of storage and a 12-volt power outlet. Bucket seats are also offered, with both cloth and leather seating surfaces. A large, 20.1-liter covered center console with additional open storage space and cupholders is paired with bucket seats configurations.

Luxury-inspired interiors

Silverado LTZ and Sierra SLT luxury-inspired premium interiors offer richly appointed features, including a distinct instrument panel design, large-capacity center console (20.1 L), unique seats, gauge clusters, steering wheels and other trim. Silverado LTZ design elements include woodgrain trim accents across the instrument panel, HVAC, radio controls, steering wheels and door controls. Sierra SLT features unique woodgrain trim pieces on the instrument panel and door controls, with brushed aluminum-appearance details on the HVAC, radio and steering wheel. Features on the premium interiors include power-adjustable heated bucket seats, leather-surface seats, leather-covered steering wheel and selective chrome trim.

Craftsmanship and quietness

Quality in the craftsmanship of the new Silverado HD and Sierra HD interiors is unsurpassed in the segment. It results from the close attention to details engineered into every facet of the cabin – from the look and feel of interior surfaces and controls, to the flushness of trim and the quietness of the driving experience.

Silverado HD and Sierra HD’s refinement is highlighted by flush surfaces, tight gaps and tolerances on the instrument panel, center stack, clusters and other components. Most gaps on the instrument panel and cluster have been narrowed to 0.5 mm or less. Some gaps have been totally eliminated. Flush-mounted accessories and controls, such as the climate control/radio center stack, create a seamless, more finished appearance – appearing as a single unit rather than components stacked together. Similar attention was given to concealing fasteners and metal structural components of all seats. There is no exposed hardware in the interior or door sills.

The interiors’ functional styling is complemented by new, soft-touch and low-gloss finishes for the instrument panel and other trim pieces. Also, the color and grain of materials were carefully selected to provide a premium look. Sculpted headliners of woven fabric and door trim panels, as well as sculpted seat backs, enhance the interiors’ perception of precision and spaciousness.

Complementing the interiors’ finely crafted look and feel is segment-leading quietness. All trim levels – even work truck models – benefit from a comprehensive system that delivers a passenger environment almost devoid of noise. This is achieved with the use of strategically placed sound-deadening and sound-absorbing material in the body structure as well as the rigidity of the vehicle frame and quieter attributes of the aerodynamically tuned exterior. The sleeker, 57-degree windshield and tuned exterior mirrors all but eliminate wind noise. Also, improved door sealing and a doors-over-rockers design help eliminate road and wind noise.

All models are built with a high level of sound-deadening material, including a new spray-on sound-deadener and cast-foam insulators. A fiberglass-sandwich noise insulator is attached to the engine side of the front-of-dash panel and a cast-foam insulator is attached to the cabin side of the panel. This mat covers the entire area behind the dash, with the foam insulator used to ensure optimal fit. There is also a 19-mm-thick insulating material under the carpet and an insulating mat at the back-of-cab that help absorb road noise and vibration.

Spaciousness and comfort

Chevy Silverado HD and GMC Sierra HD are more spacious inside, offering increased passenger comfort. There is more headroom, legroom and hip room; and the fore/aft travel of the front seat has been increased by 1 inch (25.4 mm). The recline angle is increased 20 degrees, providing drivers a greater range of comfort.

Instrument panels: New, “low and forward� instrument panels enhance spaciousness and provide a more airy feel to the cabin as well as a panoramic field of vision. (Outward visibility also is enhanced with the trucks’ faster, 57-degree windshield.) The pure pickup instrument panels are mounted approximately 3.5 inches (90 mm) lower, while the premium interior instrument panel is located 5 inches (127 mm) lower. Both instrument panel designs are integrated into the door panels, creating a swept appearance.

Seating: 2007 Silverado and Sierra heavy-duty trucks are improved with firmer seat cushion foam and more pronounced bolsters that provide increased support and ensure comfort during long drives. The front seats are slimmer, thanks to the outboard safety belts mounted to the body. This new seat and safety belt design allowed engineers to sculpt the front seat backs to provide more room for rear-seat passengers. Heated front seats are available.

Six-way or eight-way power adjustable front bucket seats are available, depending on the trim level. A new 40/20/40-split bench seat available in Silverado LT and Sierra SLE models offers seating for three, as well as concealed, lockable underseat storage and a 12-volt power outlet.

The rear seats for extended cab and crew cab models are improved with more supportive cushion material, firmer support structures and revised seat back angles. Extended cab models offer more legroom. New on extended cab and crew cab models are stadium-style folding rear seats, with a 60/40-split bench design. The seats can be easily folded up to provide a fully open load floor. Or, either section of the split seat can be stowed independently, allowing room for both cargo and a rear-seat passenger.

Entry to the rear seat/storage area of extended cab models is eased with new rear access doors that open 170 degrees.

Storage versatility

The new Chevy Silverado and GMC Sierra heavy-duty trucks offer numerous, versatile interior storage options, providing customers with useful and intuitive convenience.

Glove boxes: A “double� glove box, which includes a large-capacity, conventional glove box, provides 5.6 liters of storage capacity, and a new, covered storage compartment above it offers 3.4 liters of capacity. The lower glove box has an open design that allows storage of larger items. The glove box door is spring-damped, which enhances the quality feel of the interior.

Models equipped with the luxury-inspired premium interior come with a large glove box that offers 25 percent more storage space than previous models. Like the glove box door on base and uplevel models, the premium interior’s glove box door is spring-damped for a quality feel.

Consoles: On pure pickup interiors – when equipped with bucket seats – the Silverado and Sierra come with a new, large covered center console and open storage console extension with bins and cupholders. When equipped with the 40/20/40-split bench seat, Silverado and Sierra come with a versatile pull-down console that opens to offer 6.1 liters of storage space and includes bin dividers. The console has a wide, flat top surface that can be used as a desk or writing surface. It also incorporates cupholders at the front and a 12-volt power source.

Luxury-inspired premium interiors include large center consoles with the segment’s largest storage capacity: 20.1 liters of undivided volume. Instead of running up and over the instrument panel’s center stack, the console flows beneath it, narrowing the gaps to the instrument panel and maximizing storage space. The storage bin is large enough to store most laptop computers. A reconfigurable front cupholder insert is included, as well as molded-in cupholders for rear-seat passengers. There also are two 12-volt power sources in the console – one inside the storage compartment that allows cell phones to be charged discreetly and another at the rear of the console, which allows rear-seat passengers to use for video game or audio devices.

Underseat storage: Storage versatility extends to a new, underseat storage bin that is built into the new 40/20/40-split bench seat that is available on Silverado LT and Sierra SLE models. The lockable storage bin is located under the center seat cushion and is large enough to store a laptop computer. It also has a mat that dampens noise and includes a 12-volt power source. There also is a built-in tray for smaller items, such as pens.

Rear-seat area storage: On extended cab and crew cab models, the new stadium-style folding rear seats can be stowed to allow an open load floor across the rear section of the cab. The bottom cushions are simply folded up with one hand in a single motion, causing the rear seat to move tightly against the rear cab wall. The 60/40-split design of the seats allows both or only one seat section to be folded, enabling both cargo and a single passenger to share the rear-seat area.

Additional interior storage comes from front- and rear-door map pockets, as well as front seatback compartments that are large enough to store a road atlas. Front door panel pockets also accommodate bottles.

Convenience and functionality

Reflecting their diversity of choices, the 2007 Silverado and Sierra heavy-duty trucks are offered with numerous convenience features that are designed and integrated for intuitive function.

The gauge clusters reflect the trucks’ attention to detail, using chrome-ringed instruments with bold graphics and red pointers. A comprehensive driver information center is included on all models, with a digital readout located in the lower portion of the cluster and readouts specific to the heavy-duty models. The gauges have an analog display, with large, easy-to-read graphics. They are lit with ice-blue LED lighting, which provides crisp, bright illumination and a more upscale look. The lighting enhances the precise, jewel-like appearance of the instruments.

All controls on the instrument panels are intuitively placed within easy reach of the driver, with controls designed for easier operation with gloves in base and uplevel models. The controls have a firm, tactile feel that elevates the feeling of sophistication. Flush mounting of the controls is further evidence of the trucks’ precise build quality. An integrated, flush-mounted overhead console is used for some controls.

A manual-control climate control system is standard on all Silverado and Sierra HD models, with a dual-zone automatic system available on extended cab and crew cab models. The dual-zone system allows for up to a 30-degree F difference in temperature settings between the driver and front passengers. All systems feature upgraded controls, quieter operation, more effective cooling and improved side-window defogging. The systems also interface with the available remote starting system, allowing a vehicle to be heated or cooled when started from a distance.

Power rear side windows: Power-operated rear access door windows are available on uplevel extended cab models. The windows fully retract into the door and combine with the doors’ 170-degree openings, for an exclusive feature combination.

Power sliding back glass: Power-operated back glass is available on uplevel extended cab and crew cab models. The window operates with the touch of a button located on the overhead console.

Power sunroof: A large, power-operated sunroof is available on extended cab and crew cab models. Different versions are designed for each cab style. The crew cab sunroof has a tilt/slide design, with a sliding sun shade and express open/close feature. The extended cab sunroof uses a spoiler-type sunroof design that slides back over the roof surface.

Power adjustable pedals: Available power-adjustable pedals (extended cab and crew cab) help drivers of all statures find a comfortable and safe driving position. At the push of a button, the pedals move on an angle upward to meet the leg length of the driver.

Ultrasonic Rear Parking Assist: Ultrasonic Rear Parking Assist provides audible and visual warnings (visual via LED lights) of objects behind the vehicle.

Heated windshield wiper fluid: Another first for Silverado and Sierra is the available heated windshield washer fluid system, which more effectively removes bug spatter and thin layers of ice and frost. When the heated system is activated, washer fluid is directed to a special reservoir and heated to more than 150 degrees F (60 C) very quickly for approximately 20 seconds. Enough fluid enters the reservoir to accommodate four cycles of windshield cleaning.

Rain-sensing windshield wiper system: A rain-sensing windshield wiper system is available. It uses an infrared sensor to automatically turn on the wipers when precipitation is detected. The system varies the speed of the wipers based on the amount of precipitation.

Radios: The new Silverado and Sierra offer a diverse range of radio systems, including single-CD, six-disc, MP3- and DVD-compatible systems. Several radios featured RDS technology, which provides enhanced information for participating FM stations. Steering wheel radio controls are available.

The new family of radios in Silverado and Sierra feature large rotary controls, flush mounting and the capability of seamlessly choosing between AM, FM and XM stations. An auxiliary jack allows the use of personal music devices to be played through the vehicle’s speakers. A six-speaker performance audio system is available, as is a Bose nine-speaker premium sound system. XM Satellite Radio is optional.

Navigation system: Silverado HD and Sierra HD models now offer touch-screen DVD-based navigation radio systems that employ a 6.5-inch touch-screen display. Separate CD/DVD and navigation DVD disc slots allow music or rear-seat entertainment DVDs to be played simultaneously while using the map functions of the navigation DVD. The navigation system maps routes with 2-D or 3-D color map views on the touch-screen display. It offers instant mapping to programmed destinations. Step-by-step audio directions (in English, Spanish or French) are provided. Verbal commands instruct the driver when to turn and the system provides alerts when necessary.

Rear-seat audio system: This system enables second-row passengers of heavy-duty crew cab models to enjoy audio and entertainment options independent of the front seat passengers. The system allows a separate music source to be played through headphones and includes input jacks for items such as personal music devices and video games. The jacks also are compatible with video sources, such as video cameras. Two headphones are included.

Rear-seat entertainment: Available on heavy-duty crew cab models, the rear-seat entertainment system combines a dual-play radio system, rear-seat audio controls and a larger, 8-inch flip-down screen located in an overhead console. It includes two wireless headphones and a remote controller. The screen has a 16:9 aspect ratio and a high, 800 x 400-pixel resolution.


Page 1: Overview (I)
Page 2: Overview (II)
Page 3: Chassis
Page 4: Design
Page 5: Interior
Page 6: Powertrain

Powertrain

The new Chevy Silverado and GMC Sierra 2500HD and 3500HD heavy-duty trucks have class-leading power for any task. A new, more powerful Gen IV Vortec 6.0L gasoline V-8 engine with variable valve timing and a new more powerful version of the Duramax 6.6L turbo-diesel are the engine choices for the trucks. The gas engine is backed by a new, Hydra-Matic 6L90 six-speed automatic transmission, which features grade braking capability. Duramax diesel-powered trucks are backed by the renowned Allison 1000 six-speed automatic transmission.

The standard engine is the new Gen IV Vortec 6.0L gas V-8 (LY6). It is rated at a segment-leading 353 horsepower (233 kW) and 373 lb.-ft. of torque (506 Nm)* – approximately X percent more power and torque than the previous engine. Variable valve timing helps improve performance and fuel economy. Paired with the new six-speed automatic transmission, this powertrain combination offers a higher maximum gross combined weight rating (GCWR) – 18,500 pounds (8,392 kg) – and is the segment leader for heavy-duty pickups with a small-block V-8 gas engine.

Available in the heavy-duty trucks is a new Duramax 6.6L V-8 (LLM) engine that delivers an improved performance rating over the already superior power and torque ratings customers experienced with the previous version. It is rated at a segment-leading 365 horsepower (272 kW) and 660 lb.-ft. of torque (895 Nm). Upgrades to the engine and a new diesel particulate filter system provide a 90-percent reduction in particulate matter and a 50-percent reduction in NO x, over current standards, meeting a new federal government mandate.

“The powertrain choices in the new Silverado and Sierra heavy-duty trucks reaffirm GM’s commitment to delivering the most powerful and most capable trucks in the segment,� said Dr. Terry Woychowski, executive director, vehicle systems engineering and chief engineer for full-size trucks. “Technology, including variable valve timing and a new diesel particulate filter system, enable our powertrains to achieve segment-leading power ratings while at the same time increase efficiency and lower emissions.�

Vortec 6.0L V-8 details

The Silverado and Sierra heavy-duty trucks’ Vortec 6.0L gas V-8 is based on GM Powertrain’s Gen IV small-block V-8 engine family. It shares a basic architecture with other small-block engines, including 4.400-inch bore centers; the same design foundation on which the original and legendary small-block V-8 was developed in the early 1950s.

The 6.0L engine produces a best-in-class 353 horsepower (233 kW) at 4,400 rpm and 373 lb.-ft. of torque (506 Nm)* at 4,400 rpm on 2500HD and 3500 HD single rear wheel models, with peak torque developed early and maintained over a broad rpm range. This provides confidence and ease of operation with a full load or trailer, particularly on steep grades. Additional engine highlights include:

The Gen IV V-8 is engineered to meet stringent emissions standards. In fact, compared to truck engines of a decade ago, the Gen IV engine family is approximately 90 percent cleaner. Cast iron exhaust manifolds matched with dual close-coupled catalytic converters help reduce cold-start emissions, which is the largest source of vehicle emissions.

Variable valve timing

Variable valve timing (VVT) is a standard feature on the heavy-duty truck’s 6.0L engine. It helps optimize camshaft timing to improve low-rpm torque and high-rpm horsepower. GM’s introduction of variable valve timing through the unique dual-equal cam phaser was the industry’s first application of VVT on a mass-produced V-8 cam-in-block engine. The unique dual-equal phaser adjusts the camshaft timing at the same rate for both the intake and exhaust valves.

The system incorporates a vane-type camshaft phaser that changes the angular orientation of the camshaft, thereby adjusting the timing of the intake and exhaust valves to optimize performance and economy, and help lower emissions. It offers continuously variable valve timing in relation to the crankshaft. The cam phaser vane is attached to the camshaft on the front journal. As driving conditions warrant, the cam phaser system can reduce ignition timing at higher rpm levels to increase power. At lower rpm levels, torque is enhanced with increased timing.

Precise camshaft timing is the key to the variable valve timing system’s capability to optimize performance. Cam phasing is directed by the engine’s E38 ECM. It relies on data from a camshaft position sensor – a target ring with four equally spaced segments – that communicates the camshaft’s position quicker and more accurately than previous systems that used just a single segment. Also, a spring-loaded tensioner is used on the timing chain to ensure precise tension.

Quiet, durable operation

Like all Gen IV small-block V-8 engines, the heavy-duty trucks’ 6.0L is designed for quiet operation, including:

The quiet features of the engine are complemented in the vehicles with strong engine cradles and mounting systems. These systems help reduce vibrations transmitted through the chassis that would otherwise be felt by vehicle passengers.

Backing the new engine’s quietness is the assurance of long-lasting performance. The Gen IV engine family was validated under extreme conditions, with the heavy-duty trucks’ 6.0L engine dynamometer-tested to the equivalent of 200,000 miles – 50,000 miles more than other engines in the family. The engines also feature many long-life engine components that can reduce maintenance intervals and costs. The iridium-tip spark plugs, engine coolant, accessory drive belt and sealing gaskets are some of these items.

Some of the stringent durability testing included cycling engines between the peak torque and peak horsepower rpm points – the equivalent of towing a heavy trailer up a steep grade – for 600 straight hours.

Enhanced 6.6L Duramax diesel

GM Powertrain’s powerful Duramax 6.6L V-8 turbo-diesel engine is revised to meet new, stringent 2007 federal emissions regulations, while delivering increased horsepower and torque. It is rated at a segment-leading 365 horsepower (272 kW) and 660 lb.-ft. of torque (895 Nm).

Upgrades to the engine and a new diesel particulate filter system, along with the use of new, ultra-low sulfur diesel fuel, help the Duramax achieve a 90-percent reduction in particulate matter and 50-percent reduction in NO x, as required by the new emissions standard. All diesel engines manufactured beginning in January 2007 are required to meet the new emissions standard.

“Maintaining power and torque leadership with the Duramax is important because it’s the benchmark that built its class-leading reputation with our customers,� said Charlie Freese, executive director, GM Powertrain Diesel Engineering.

Revised for 2007, the Duramax diesel uses a variable-geometry turbocharger to optimize boost performance over a wide range of operating conditions. This provides the customer with seamless and immediate response, while simultaneously helping to reduce emissions. The turbo, which spins up to 120,000 rpm, is high-speed-balanced for minimal noise and vibration, while contributing to the engine’s overall smoothness and refinement. Maximum boost is 20 psi. Additional details of the Duramax 6.6L V-8 engine’s ’07 enhancements include:

The engine also features a rigid cast iron cylinder block with induction-hardened cylinder bores; four-bolt, cross-drilled main bearing caps; forged steel, nitride-hardened crankshaft; aluminum pistons with jet-spray oil cooling; aluminum cylinder heads with four valves per cylinder; water-cooled turbocharger; integrated oil cooler and a charge-cooled turbocharging system.

Meeting the new emissions standard

To meet the new 2007 emissions regulation, the Duramax 6.6L V-8 engine features:

The 6.6L engine’s DPF is based on GM-patented technology and proven supplier components. It traps diesel particulate matter in a honeycomb-like ceramic “brick� after it travels through an oxidizing catalyst. The exhaust gases are then routed out through the exhaust system. An automatic regeneration process periodically uses exhaust heat to remove the soot from the DPF.

An onboard computer controls fuel injection and oxygen content to adjust the exhaust energy to the appropriate level to clean the particulate trap. The DPF and corresponding components will change the exhaust system length and/or outlet design, depending on the vehicle model. Also, an expanded underbody heat shield is added.

New Hydra-Matic 6L90 six-speed RWD transmission

Supporting the high-performance capabilities of the 6.0L gas engine is the new Hydra-Matic 6L90 six-speed automatic transmission. It has a wide, 6.04:1 overall ratio – including two overdrive gears – that helps deliver an excellent balance of performance and fuel economy.

The 6L90 has a steep, 4.02:1 first gear, which provides a very strong launch feel, and shorter “steps� between all gears, allowing the transmission to quickly find the best gear and reducing hunting on grades – a trait that is especially helpful when towing. The two overdrive gears include a 0.85:1 ratio in fifth gear and a 0.66:1 ratio in sixth. With two overdrive gears, engine rpm is reduced by approximately 19 percent at 60 mph. Lower engine rpm can bolster fuel economy because less fuel is used. A lower-rpm cruising speed also enhances smoothness and reduces noise heard in the vehicle’s cabin.

Gear changes from second to sixth gears are accomplished with clutch-to-clutch control that allows a greater degree of smoothness at lower vehicle speeds. The clutch-to-clutch operation is achieved with three planetary gears, three stationary clutches and two rotating clutches. It is a simple, less complex design that enables the six-speed transmission to be packaged in a size not much larger than a four-speed automatic. All forward gear shifts feature clutch-to-clutch operation.

A new, 32-bit electro-hydraulic control module monitors the transmission to ensure consistent performance. The 6L90 has the capability for adaptive shit controls and other features such as grade braking, and Driver Shift Control with tap up/tap down shifting, which allows the driver to manually select upshifts and downshifts with a button on the column shifter. Tow/haul mode is a driver-selectable feature that reduces shift busyness when towing or hauling a heavy load. Auto grade braking is available when the tow/haul mode is selected and the transmission is not in the range selection mode.

Allison six-speed automatic details

The Allison 1000 six-speed automatic transmission is partnered with the Duramax 6.6L turbo-diesel engine. It is a strong, durable and proven transmission that matches the prodigious torque output of the Duramax diesel engine. This six-speed transmission also delivers good fuel economy, quietness and control. It features a class-first range selection function, which allows the driver to easily select the desired gears to match driving conditions, such as towing a trailer on a steep grade.

The transmission’s sixth gear – essentially a second overdrive gear – enables a wide, 5.08:1 overall forward gear ratio and allows the vehicle’s engine to operate at lower rpm, particularly during higher-speed driving on highways and freeways. Its 0.61 ratio provides a 1,550-rpm engine speed at 60 mph, compared with the five-speed transmission’s 1,800-rpm engine speed at 60 mph. The engine uses less fuel at lower rpm, enabling increased fuel mileage and range.

The range selection feature complements the tow/haul mode and allows the driver to select the desired gears, via a thumb-activated switch on the shifter, providing a feeling of enhanced control in unique driving situations, such as towing on a steep grade. The range selection feature holds the gear pre-selected by the driver, and electronic safeguards prevent the transmission from being shifted in a manner that could cause engine damage or loss of vehicle control. Grade braking and cruise grade braking are available when the tow/haul mode is selected and the transmission is not in the range selection mode.

A low-traction mode also is a feature of the Allison transmission. When the driver selects second gear while stopped and wheel slip occurs, the transmission torque-manages the engine to limit tire slip on slippery road surfaces. The Allison 1000 also has a unique, GM-patented elevated idle mode, which allows for faster interior warm-up. The system, which is activated through the vehicle’s driver information center, is synchronized with the engine. When elevated idle is active, the transmission increases the load on the engine so that it will generate heat more quickly and warm the interior in less time.

*SAE certified. A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005 . This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing. GM was the first auto manufacturer to begin using the procedure and expects to use it for all newly rated engines in the future.