The only major truck unveiling at this years chicago auto show the new HD silverado debuts the Generals brand new 6.6 liter duramax diesel engine
By Andrew Ganz
To combat freshly revised competitors from Dodge and Ford, Chevrolet has thoroughly revised its Silverado Heavy Duty for 2010. The truck might look more or less the same, but Chevrolet says the frame has been bolstered, a new independent front suspension offers more strength and a more powerful 6.6-liter Duramax diesel will be available.
Chevrolet hasn’t released horsepower and torque specifications for the new Duramax yet, but the automaker says both figures will top the 2010’s 365 horsepower and 660 lb-ft. of torque. In addition, the new Duramax has reduced NOx emissions by 63 percent, is quieter and should offer better fuel economy than the outgoing engine. The new 6.6-liter engine will offer B20 biodiesel capability. It will require diesel exhaust fluid injection refills every 5,000 miles, an improvement over the existing powertrain according to GM.
The engine’s new glow plugs can prepare the engine for starts in as little as 3 seconds in -20F weather.
An enhanced Allison 1000 six-speed automatic transmission will also be part of the new package. It will come with tap up/tap down driver shift control and an elevated idle mode to speed the warm-up process. GM says that the transmission helps 6.6-liter 2500 HD models accelerate to 60 mph in less than 9 seconds, a 0.3 second improvement over the outgoing model.
The Silverado HD will come standard with a mildly modified 6.0-liter V8 hooked up to the automaker’s 6L90 six-speed automatic. A new camshaft profile increases low-end torque for better off-the-line performance and better high-altitude trailering.
GM is especially proud of the Silverado HD’s new exhaust brake system, which uses the turbine control of the turbocharger and the engine’s compression to generate backpressure to slow the truck without using the brakes or transmission. The system is designed to work more efficiently and quieter than existing trailer braking systems in higher altitudes.
Still, Chevrolet has upgraded the the Silverado HD’s brakes to a four-channel ABS system on single rear-wheel models and a three-channel system on dualies. The front and rear rotors are increased to 14 inches in diameter and the booster has been recalibrated.
Wheelbases are increased across the line to go with a the 11 new fully-boxed frames. GM says rigidity us up 92 percent in bending and 20 percent in beaming, while the front structure is 125 percent stiffer than before. The frame-mounted hitch is now stronger thanks to a box tube design; it now supports 16,000 lbs.
The new frames hold an all-new independent front suspension that has a 25 percent greater front axle rating (6,000 lbs.). The basic design is unchanged, but stronger forged steel upper control arms and cast iron lower control arms add strength and reduce weight. GM says that the system improves handling and ride while increasing strength for front end attachments.
The rear leaf spring suspension gains a larger asymmetrical leaf design that are wider than existing models. The 2500HD models get a two-stage leaf spring design, while 3500HDs get a three-stage setup. Gross rear axle ratings are up across the board.
Naturally, towing capacity has increased. a 3500HD crew cab with the long box can tow up to 20,000 lbs. with a fifth-wheel hitch, besting 2010 versions of Dodge’s Ram and Ford’s F-Series Super Duty. Ford has yet to release figures for its redesigned 2011 F-Series Super Duty, however.
Maximum payload is up to 6,335 lbs., again besting 2010 Ram and Super Duty models.
The 2011 Silverado HD will offer 170-degree rear access doors for extended cab models, bolstering interior cargo hauling ability.
A 36-gallon gas tank is now standard, giving the 6.6-liter Duramax a roughly 680-mile range.
Minor styling changes have been made to the front bumper, hood and 20-inch alloy wheels. GM says that the redesigned trucks will go on sale during the summer of 2010. A GMC Sierra version should follow shortly thereafter.
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