2011 Sierra Denali HD 4WD

2011GMC Sierra Denali HD

by Bruce Hubbard

The Auto Advisor Group

A touch of the pedal and the  2011 GMC  Sierra Denali pushes you back in the seat like a powerful sports car. This large truck can get to 60 miles per hour from a stop in under 9 seconds. Quarter mile in under 16 seconds with  top and a speed of nearly 90 miles per hour on average.  

The new 6.6L Duramax diesel delivers more power than the previous model. The Duramax GMC states gets 11-percent greater highway fuel economy, up to 63-percent lower emissions, B20 biodiesel capability and quicker acceleration.

The new Sierra Denali or its twin the Chevrolet Silverado both are faster than the Ford F250 Diesel. However, the Ford 250 has more horses and torque and ability to tow. The F250 HD 400 horsepower and 800 foot pounds of torque.  Matching Ford ratings is available from the RAM Heavy Duty for another $500 above the Cummins Diesel and upgrade to offer 800 foot pounds of torque. The RAM still retains 350 horsepower. 

The 2011 GMC Sierra Denali has the superb Allison six-speed transmission. The enhanced Allison 1000 is strengthened to handle the higher torque capability of the new 6.6L Duramax engine, while also helping to improve fuel economy and provide seamless assistance with a new exhaust brake system. Greater efficiency is delivered through reduced “spin loss” – meaning, the transmission channels more of the engine’s power to the axles, allowing it to do more with less fuel.

The Allison 1000 also features driver shift control with tap up/tap down shifting and a patented elevated idle mode cab warm-up feature. Also, the tow/haul mode reduces shift cycling for better control and improved cooling when towing or hauling heavy loads. The six-speed configuration retains its two overdrive gears for optimal efficiency.

“The new Sierra Denali HD is the latest expression of GMC’s Denali philosophy of blending capability with premium features and styling,” said Lisa Hutchinson, GMC product marketing director.  The Sierra Denali HD is truly a magnificent truck that is capable in any work environment.

The 2011 GMC Sierra Denali 4WD Crew Cab truck has all the luxury one would expect in the finest sedans or coupes. Optional are heated and cooled leather seats plus a heated steering wheel!  All the luxury items a real work truck deserves. Back up camera, a great navigation system plus Bose audio system  that is state of the art. Inside the cabin we find the Sierra Denali-specific brushed aluminum trim. The 2011 Denali HD also has power-adjustable pedals.

The interiors feature numerous storage compartments, providing covered access for everything from work gloves to laptops. For those who use their truck as a mobile office, Sierra Denali HDs deliver with available mobile WiFi, USB connectivity, Bluetooth connectivity, XM Satellite Radio and a navigation system. Multiple charge points enable multiple electronic devices to operate simultaneously; and when equipped with the available navigation system, XM NavTraffic offers real-time updates of traffic conditions (in selected areas) that can help plan the most effective route to the job site.

The new Sierra Denali HDs are crew cabs available only in the 2500 series (3/4-ton), 2WD and 4WD configurations, as well as the 3500 Series (1-ton) 2WD and 4WD in both single-rear-wheel and dually versions. The 3500 series is also available in standard (6-foot 6-inches) and dually long box (8-foot) versions. The 4WD 2500 Denali HD I drove in the back roads of Pennsylvania I enjoyed.

The Denali four-bar, chrome grille with round air inlets distinguishes the Sierra Denali HDs on the outside, along with body-color bumpers, chrome door handles, chrome accents 18- and 20-inch polished forged aluminum wheels.

The exterior is offered in three colors: Black, Stealth Gray and White. 

The new model has a greater towing capability 21,700 lbs. and payload 6,635 lbs. supported by all-new fully-boxed, high-strength-steel frames and strong suspensions for maximum capability and exceptional ride characteristics.

For the long haul drivers will be happy with the larger gas tank and fuel economy improvements for up to 680 miles between fill-ups with the 6.6L Duramax turbo diesel.

On the hilly back roads in Pennsylvania I used the new standard  “smart” exhaust brake feature for greater control on grades and reduced brake pad wear.

Other features I like in the Sierra Denali include trailer sway control, integrated trailer brake control, hill start assist, automatic grade braking, intelligent brake assist and larger brakes.

The trailer sway control system provides an added measure of confidence when towing a trailer. The system senses conditions of trailer sway and intervenes with braking and/or reduced engine power to bring the trailer under control and keep it on its intended path. The system uses electric trailer brakes when a trailer is plugged into the standard wiring harness of the truck, and its performance requires no input from the driver.

The hill start assist system is automatically engaged when sensors detect the vehicle is on a grade of about 5 percent or greater. It holds the brakes for about 1.5 seconds or until the gas pedal is pressed, preventing rollback. It is particularly effective when towing, giving the driver time to switch from the brake pedal to the gas pedal without rolling.

Depending on the model, Sierra HD models offer Segment-leading fifth-wheel towing capacity of 21,700 pounds.  Conventional towing capacity increases to a segment-best 17,000 pounds. Improved payload capability of 6,635 pounds on a complete vehicle.  Segment-leading Gross Combined Weight Rating increases to 29,200 pounds.  Gross Vehicle Weight Ratings increases up to 17 percent to 13,000 pounds.   Front Axle Weight Rating increases by up to 25 percent to 6,000 pounds.

The frames have increased cross sections and use more high-strength steel for greater durability, higher towing capacity and improved ride and handling; the front sections are hydroformed. GM states that bending and beaming stiffness of the frames is increased 92 percent and 20 percent, respectively, with the fully boxed sections enhancing torsional stiffness by a factor of five. Also, larger engine and transmission mounts, coupled with a 125-percent-stiffer front frame structure, provide greater vibration control, while hydraulic body mounts are incorporated under the cab section on extended and crew cab models for a more isolated feel inside.

Engineers addressed common customer and aftermarket uses when designing the new frames, including adding access holes to the rear frame section to enable easier installation of fifth-wheel/gooseneck-style hitches. Also, the frame-mounted hitch for conventional trailering is stronger, with a box-tube design. It supports up to 17,000 pounds.

A completely redesigned independent front suspension system offers up to a 25-percent greater front axle weight rating – up to 6,000 pounds front gross axle weight rating  – so a snow plow can be used on all 4WD cab configurations with the available snow plow prep package. Sierra’s signature short-long arm/torsion bar front suspension design is retained, but now features new, forged steel upper control arms that are stronger and lighter than their predecessors.

The new lower control arms are made of precision-machined cast iron to handle the greater loads. Five different torsion bar rates support five different front gross axle weight ratings (a single torsion bar was previously used for all models). This helps stabilize the range of trim heights of various models under load, while enhancing appearance, handling, durability, tire wear and alignment. The trim height is adjusted on each bar via a single bolt, easily allowing the height to be changed to account for the weight of a snow plow or other accessories.

The Sierra Denali HD front suspension now uses a pair of urethane jounce bumpers on each side, instead of one, for improved load management; and there’s a new upper shock mount attachment design that’s positively connected to the frame with two fasteners. This design eliminates squeaks and clunks, while supporting higher load capability and increased durability.

The 2500HD models feature a two-stage leaf-spring design, while 3500HD models have a three-stage design. All models feature 3-inch-wide (76 mm) leaf springs that are 20-percent wider than previous models. The larger leaf-spring design supports increased rear gross axle weight ratings across the board. On the 2500HD models, the rating is 6,200 pounds  – up from 6,084. On 3500HD models, the rating increases to 7,050 pounds on single-rear-wheel models and 9,375 pounds on dual-rear-wheel models – the latter representing a nearly 14-percent increase over the previous 8,200-pound rating.

Longer wheelbases – ranging from 133.6 inches  to 167.7 inches – and wider front/rear tracks enhance the ride and handling characteristics of the Sierra 2500HD and 3500HD, giving them a greater feeling of smoothness and control. The longer wheelbases and wider tracks are complemented by the new, stiffer frames, new jounce bumpers, shock mounts and hydraulic body mounts to provide a solid, smooth and isolated driving experience. New shocks were specially valved to support the new trucks’ weight ratings, while balancing excellent ride characteristics.

A revised steering system designed to support the trucks’ greater front gross axle weight rating also enhances the driving experience. It includes a new, larger steering gear, power steering pumps and linkages. The pumps (different parts for gas and diesel models) deliver greater pressure for reduced steering effort in low-speed and parking maneuvers; they are also quieter. On some models, the new linkages feature a compliant joint added at the pitman attachment to enhance handling.

The standard four-wheel disc system is completely revamped to deliver smoother, more immediate and confident-feeling performance. Four-wheel, four-channel ABS is standard on all single-rear-wheel models and a three-channel system is standard on dual-rear-wheel models. The front and rear rotors are larger in diameter – 14 inches (355 mm) – and width on all models to support their increased capacity, weight ratings and trailering ratings, while the calipers are stiffer and stronger.

The 2011 Sierra 2500HD and 3500HD models have a comprehensive roster of safety features and functional technologies that include:

StabiliTrak electronic stability control system on all single-rear-wheel models larger, four-wheel disc brakes with standard four-wheel ABS a new high-strength steel tubular frame cross member that enhances safety and improves crashworthiness seat pelvic/thorax and head curtain side air bags available on 2500HD

For 2011, the Sierra heavy-duty lineup expands to include 12 2500HD models and nine single- and dual-rear-wheel 3500HD models – including a new 3500HD Crew Cab with a 6.5-foot cargo box. Other models are offered in WT, SLE and SLT trim levels, while popular features such as the EZ Lift tailgate and rearview camera system are retained.

The interiors have excellent attention to detail and are quieter – thanks to the range of the truck's enhancements. The stronger chassis, quieter Duramax engine and even details like a quieter power steering pump contribute to the Sierra HD delivering exceptional quietness.

The 2011 Sierra HDs drive farther without stopping to refuel. A new, 36-gallon fuel tank is standard on all models and, with the improved fuel efficiency of the powertrains, enables a cruising range.

All 2011 Sierra 2500HD and 3500HD trucks work under the best warranty coverage in America: a five-year/100,000-mile limited powertrain warranty, plus roadside assistance, courtesy transportation and other features that provide assurance that GMC backs its trucks for everything the road offers.

The steering is superb in the 2011 GMC Denali HD. Important when you trailer a large boat and want to keep it on the highway.

When I hit the brakes I was secure in knowing the big HD could stop quickly. In fact it stopped from 70 miles per hour  in just 216 feet. All the diesel trucks from Ford and Ram stopped just as quickly.

The GMC Denali package cost is $1305 more than a similar Sierra SLT. The main Denali package has a monochromatic exterior appearance. The base price for a gasoline Denali HD is $46,860, the diesel option jolts the sticker north by $7195. The Allison transmission  is another $1200, bringing the base price of the diesel to $55,255. My test vehicle also had the optional navigation system ($2250), a sunroof ($895), 20-inch polished aluminum wheels ($850), chrome running boards ($689), heated and cooled front seats ($650), a rearview camera ($450), a heated steering wheel ($150), and a pair of engine covers for the grille and bumper opening that are required on diesel trucks sold in cold-weather states ($55).

Although the total of $61,189.00 plus is expensive consider that the Diesel and Allison almost add $10,000.00 to the base price.  Ford and RAM come in close the 60 k when outfitted with their diesel package and similar options.

 “GMC has been one of the industry’s strongest truck brands for more than 100 years, and we back the 2011 Sierra HDs with a comprehensive five-year/100,000-mile powertrain warranty that provides the best coverage in America,” said Hutchinson. “From greater diesel power to the segment-best warranty, these trucks deliver strength and peace of mind on all fronts.”

Chevrolet takes the heavy-duty pickup battle to the test track – and the mountain roads – in "HD to HD," a video series that pits 2011 Silverado HD pickups against the competition in real-world tests of capabilities that matter to real-world truck buyers.

"We wanted to get away from spec-sheet comparisons and show how these trucks perform in the real world," said Rick Spina, global vehicle line executive for full size trucks. "To do so, we engaged an independent company to test the Silverado HD with the Duramax diesel and Allison transmission head-to-head with the competition, and record those tests for everyone to see."

The tests include acceleration, passing, and braking tests, all conducted with a loaded bed, or in some cases, a loaded trailer.  Other tests measure the effectiveness of the exhaust brakes on long downgrades and the stiffness of the frames during twist-ditch simulations. Competitors were diesel-powered 2011 Ford Super Duties, and in some tests, 2011 Dodge Ram HDs.

For example, in a zero-to-60 test of three-quarter ton models with a 1,500-pound load, designed to simulate merging onto a busy freeway, the Silverado 2500HD outpaced the F-250 Super Duty, 7.66 seconds to 8.36 seconds, despite the slight advantage in published horsepower and torque ratings for the Ford.

"We worked hard on the Duramax-Allison combination to deliver torque smoothly throughout the entire power band," said Spina.  "That is what gives us class-leading acceleration." It is very impressive to drive the GMC Duramax . The Allison moved me up to 70 MPH in no time.

Silverado HD pickups showed a similar advantage in acceleration tests on a 7-percent grade, and in passing tests at both sea level and at 6,000 feet above sea level while towing loaded trailers.

I love all the Diesel products that the Big Three offer.  The GMC Sierra and Chevy Silverado have up to date exterior designs and great interiors.  But, you can get the most luxurious interior with the Ford King Ranch or high end Ford Heavy Duty. Don’t forget the Ram HD it has great looks and wonderful interiors offered. If you like after market accessories no one has more than the 2011 RAM with MOPAR.