There aren't many visual reminders that the 2011 Chevrolet Silverado HD trucks are virtually all new beneath the sheetmetal. If we were talking about a midsize sedan that might be a problem, but truck owners will be happy all the development money went into a new Duramax engine, an all-new frame, and significant upgrades to payload and towing capacities instead of new body panels.
The heart of any heavy duty truck is its engine and Chevy is offering enhancements to both the 6.0-liter gas V-8 and the 6.6-liter turbo-diesel Duramax V-8 engines for 2011. Changes to the 6.0 gasser are minimal (basically just a revised camshaft design) but that's enough to potentially change the horsepower and torque output.
The biggest powertrain news is the revised Duramax engine and Allison transmission combo. Environmentalists will be happy the diesel powerplant reduces NOx emissions by at least 63 percent over the outgoing truck and B20 biodiesel can now be burned in the Duramax without any problem. Diesel exhaust fluid (a urea mixture) is needed to meet emissions regulations, but the tank is big enough to last approximately 5000 miles for most users. Horsepower, torque, and fuel economy figures are all expected to improve for the new Duramax, but final SAE certification hasn't happened yet. It's worth noting the fuel economy of trucks this heavy isn't monitored by the EPA (so it won't appear on the window sticker) but Chevy is already hoping third parties will do fuel economy tests once the trucks are on sale this summer.
Enhancing the available engines and transmissions wouldn't do a whole lot without structural improvements to the trucks, so Chevy developed an all-new frame and suspension for the heavy duty trucks. Literally everything on the frame is new other than stabilizer bar connectors up front and the physical size of the components is astounding. Looking at the frame makes the 20,000 lb towing capacity seem like an understatement. The fully boxed frame rails are seriously beefy and the crossmembers are much, much larger than last year's.
Front suspension components have been upgraded so every four-wheel-drive crew cab truck can now support the weight of a snowplow. The independent suspension also keeps the front tires in constant contact with the ground and allows for greater adjustment of the alignment for different loads the truck may face. No other heavy duty truck offers an independent front suspension. Out back there are asymmetrical leaf springs that help control axle hop.
Towing as much as 20,000 pounds or hauling 6,335 pounds requires some serious brakes, so the Silverado is fitted with 14.0-inch rotors front and rear as well as a revised calibration for the hydroboost system to give better pedal feel. Trucks equipped with the exhaust brake will be even easier to control on hills. Chevy still offers an integrated electronic brake controller to help manage trailer brakes.
Electronic aids are also making their way into the realm of heavy duty pickups with the 2011 Chevrolet Silverado HD. Electronic stability control will be standard for single-rear-wheel trucks as well as ABS, hill start assist, and trailer sway control. Since the Silverado is a GM product, expect to find an OnStar button on the rearview mirror as well.