Road Test: 2007 Chevrolet Silverado HD
Heavyweight Prize Fighter: In this corner, the 2007 Chevrolet Silverado HD
Unless you've been living under a rock, you know there's a war raging in the heavy-duty marketplace. These are the vehicles designed and sold to do the heavy lifting for job sites, contractors, and even toy-hauling families. If you have something to tow or carry a burdensome load, this is the segment that's battling for your attention. And this year, all three heavy-duty truck manufacturers are coming out with something new. Ford upped the ante first with the introduction of the F-450 Super Duty, then Dodge showed its Ram HD 4500 and 5500 chassis cabs, and now GM has just released its 2007 2500 and 3500 Silverado HDs.
As a follow-up to last year's half-ton Silverado (our 2007 Truck of the Year), GM is introducing the more rugged three-quarter- and one-ton versions, with many of the same exterior and interior design cues.
Unlike Ford's strategy of visually separating the light-duty F-150 from the larger and stronger Super Duty F-250, F-350, and now F-450, General Motors is keeping its pickup-truck line visually connected, no matter what the maximum trailer rating. You'll notice a similarity between the half-ton and heavy-duty's hood and body panels. The Chevy has a wider and taller dual-port grille, similar in shape to the half-ton's. Likewise, the hood has two muscular bulges running down the length, ending at the rear corners with a ridged, plastic covering (that includes a label identifying the engine inside), and it does offer some venting through the hood. The GMC grille has a wide mouth ringed in chrome with a prominent GMC emblem in the center. Its hood has the familiar half-ton power bulge, flanked by a jeweled headlight surround.
Engine choices have been simplified to include one gas and one turbodiesel motor. Gone is the old-school Vortec big-block 8100 altogether, while the new Gen-IV OHV 6.0-liter V-8 is the gas engine of choice. Now with variable valve timing, the 6.0-liter produces 353 horsepower and 373 pound-feet of torque, both at 4400 rpm. Don't be fooled--this isn't just a warmed-over version of the same VortecMAX engine GM's had lying around. This is the industry's first application of a mass-produced overhead-valve V-8 that can adjust cam timing at the same rate for intake and exhaust. The result is more power, better fuel economy, and a small-block V-8 that's about 90 percent cleaner-burning than the comparable engines of just 10 years ago.
This engine also gets a stronger version of the Escalade and Yukon Denali's 6L80-E transmission--now called the 6L90 six-speed. The new transmission has a 32-bit electrohydraulic control module to ensure smooth shifting as well as offering a Driver Shift Controller for thumb-controlled tap-up/down shifting. The system has a Tow/Haul button to help with grade braking and holding shifts longer when loaded.
On the diesel side, the 6.6-liter Duramax turbodiesel V-8 remains the tool of choice for more than 60 percent of heavy-duty buyers, and this latest version has a few improvements: It now runs on ultralow-sulfur diesel, the cylinder block is strengthened, the aluminum heads revised, the variable-fin turbocharger can react faster, the pistons are now aluminum, and, to meet the new 2007 federal emissions regulations, there's a sophisticated series of particulate filters that collect soot and other emissions. These upgrades allow the Duramax to offer a segment-leading 365 horsepower and 660 pound-feet of torque and to be among the cleanest diesels ever sold in the U.S. Of course, all this power and new technology comes at a cost: The diesel option is $7185, plus another $1200 for the mandatory Allison 1000 six-speed transmission. Like the 6L90, the Allison also has a new 32-bit controller to keep the shifts between gears smooth and solid. This transmission also has a Tow/Haul button that can hold gears longer when accelerating under load and downshifts sooner when braking. Additionally, the Allison can be manually controlled with a thumb-shifter on the column stalk. Those who tow (or race) will love this feature. We worked the gas and diesel's transmissions hard under full payload and empty conditions and found the shift hits surprisingly comfortable when empty and responsive when hauling and towing.
The information readouts you get with GM products are a cool bonus, as you can scroll between transmission temperature readings to rear-tire pressures to engine hours. That's information a real truck guy wants access to with real numbers, not just an idiot light or numberless gauge. This powertrain and tech center could be the standard for the category (although, so far Chevy doesn't have a product answer for the new bigger, stronger F-450 Super Duty King Ranch).
Almost as impressive as the improved powertrains, the interiors are upgraded from the previous generation. Like the GMT900 half-tons before them, the HD interiors have three trim levels (WT, LT, and LTZ for Chevy, and WT, SLE, and SLT for GMC), and two dash layouts (Pure Pickup and Luxury Inspired). By now, many know that the Pure Pickup is the more work-friendly of the two: It allows front bench seating and more room for big boots, but also offers a second glovebox and has a different, oversize door grab-handle design. The uplevel interiors offer the same type of large center-stack console as those in the 1500 and GM full-size SUVs. Nav and entertainment systems are available in all configurations, and those heavy-duty owners who have to use their truck more than just heaving bags of concrete or aggregate around will enjoy how quiet and sumptuous the new HD interiors are.
There's nothing new about the cab configurations, however: familiar regular, extended, and crew cabs are offered. Extended-cab HDs will have 170-degree, dual-hinge rear doors for easy access, and the four-full-size door models have rear seats that fold into the seatbacks for a tremendous amount of interior cargo volume. HDs will come with three bed sizes, five wheelbases, three cab models, two different suspension packages (including a new Z71 choice in 4x4 or 4x2), single and dual rear-wheel options on 3500 trucks, and pricing starting from $24,575 (WT Regular Cab 4x2 longbox), working all the way up past $40,000.
GM has finally included an integrated trailer-brake controller with its Z82 trailering package (which also includes a hitch, wiring, and bigger mirrors), much like the system Ford uses in its Tow Boss setup. Maximum trailer ratings (bumper-mounted hitch) for the new Heavy Duties range from 11,600 to 13,000 pounds, with fifth-wheel maximum trailer ratings reaching 16,000 (for a look at various weights and loads, see "By the Numbers"). HDs can carry between 2100 and 5300 pounds on its back, depending on the vehicle. Look for a comprehensive tow test in a future issue. This segment is steadily growing, so we're likely to see more interest in this size category in the years to come, maybe even from import companies.
GMC Sierra HD No big surprises here. Anything you can order on the Chevy you can get from GMC as well, except now there's more visual distinction. Long the red-headed stepchild, GMC is beginning to carve out its own territory away from Chevy. First it was the premium-trim Denali brand, making its way onto pickup trucks and SUVs, and now the Acadia crossover is turning heads and opening GMC up to an entirely new market segment. Don't be surprised if GMC has a few more trick trucks up its sleeve. With all the play in the luxury-truck market, how far away can the Crew Cab Sierra 3500 Denali option package be? Certainly Cadillac can't play there, but GMC can. A few exclusive accessories, some plush carpeting, and a large-screen DVD player and Bose system--we'd tow our boat to the river in one of those. More to come, we're sure.--M.W.
|Chevrolet Silverado HD & GMC Sierra HD|
|Location of final assembly||Pontiac and Flint, Michigan|
|Body style||Regular, extended, crew cabs|
|EPA size class||Full-size truck|
|Drivetrain layout||Front engine, 2WD/4WD|
|Base engine||90° V-8, cast-iron block, alum heads|
|Bore x stroke, in||4.00 x 3.62|
|Valve gear||OHV, 2 valves/cyl|
|SAE horsepower, hp @ rpm||353 @ 6400|
|SAE torque, lb-ft @ rpm||373 @ 4400|
|Recommended fuel||Regular unleaded|
|EPA fuel econ, city/hwy||Not required over 8500 GVWR|
|Optional engine||90° TD V-8, cast-iron block, alum heads|
|Bore x stroke, in||4.06 x 3.90|
|Valve gear||OHV, 4 valves/cyl|
|Fuel induction||Direct injection, common rail|
|SAE horsepower, hp @ rpm||365 @ 3200|
|SAE torque, lb-ft @ rpm||660 @ 1600|
|Recommended fuel||Diesel No. 2|
|EPA fuel econ, city/hwy||Not required over 8500 GVWR|
|Base transmission||6L90 6-speed automatic|
|Optional transmission||Allison 1000 6-speed automatic|
|Axle ratios||3.73:1, 4.10:1|
|Transfer-case model||MP 244|
|Crawl ratio (1st x axle gears x low range)||40.8:1, 34.6:1|
|Wheelbases, in||133.0, 143.5, 153.0, 157.5, 167.0|
|Lengths, in||224.7, 230.3, 240.0, 249.2, 258.7|
|Widths, in||80.0, 95.9|
|Heights, in||75.6, 75.9, 76.3, 76.7, 77.1|
|Tracks, f/r, in||68.6/66, 68.6/74.7|
|Bed sizes LxWxD, in||78.7x62.4x21.0, 97.6x62.4x21.0|
|Base curb weight, lb||5308-7371|
|Payload capacity, lb||2294-5307|
|Towing capacity, lb||12,100-16,000 (fifth wheel)|
|Fuel capacity, gal||26.0-34.0|
|Suspension, f/r||IFS, double A-arm, torsion bars/live axle, leaf springs|
|Steering type||Power recirculating ball|
|Turns, lock to lock||3.25|
|Turning circle, ft||45.3-55.1|
|Brakes, f/r||12.8-in vented disc/12.8-in disc, 4WABS|
|Wheels||17 x 7.0-inch alloy|
|Base price range||$24,575-$41,010|