First Look: 2011 Chevrolet Silverado Heavy Duty
Duramaxed-Out: It's what's Underneath that Counts
Truck sales may have taken a beating over the past few years, but they're still among the top-selling vehicles in the U.S., so it's not surprising that automakers are continuing to invest heavily in offerings like the updated 2011 Chevrolet Silverado Heavy Duty, which is making its debut at the 2010 Chicago auto show.
Though it may look nearly identical to the existing Silverado HD, save for small refinements to the hood, grille and front bumper, don't let that fool you. The real story lies beneath, where Chevrolet has made big improvements to the structure and powertrain that the company promises will make this truck a segment-leader in towing and hauling, all the while burning cleaner and making more power.
Starting under the hood, Chevrolet is rolling out the latest version of the 6.6-liter Duramax turbodiesel V-8, which has been reworked internally to increase strength and improve efficiency. How much, Chevy won't say yet, but the company promises that the new mill will put out "significantly" more power than the current engine, which churns out 365 hp and 660 lb-ft of torque. If you don't need that much twist, there's always the 6.0L Vortec gasoline V-8 which is mostly unchanged save for a new camshaft that increases torque at low RPM.
If you want to sample Chevy's latest gizmos, though, you'll want to stick with the oil burner. Internally, the Duramax has seen its oiling system upgraded substantially and the engine can now be run on B20 biodiesel without any modification. Altogether, Chevy says the improvements are good for an 11% increase in highway fuel economy and a range of 680 miles thanks to a 36-gallon fuel tank.
Those aren't the only new tricks the Duramax has learned either. With a urea solution injected into the exhaust stream from a 5.3-gallon tank that will reportedly last 5,000 miles between fill-ups, Chevy says it has reduced NOX emissions by 63%. A new diesel particulate filter now lasts for 700 miles between regenerations, a full 300 miles longer than the outgoing truck.
The real gem, though, is the new exhaust brake. Like the system that debuted on the Ram Heavy Duty, when activated the system increases exhaust backpressure and uses the diesel's high compression to slow the truck down. Rather than simply turning the exhaust brake on or off, the system varies the engine braking depending on conditions to help slow the vehicle smoothly. When used with the cruise control, it can maintain the truck's speed down a grade without the driver having to step on the brakes and deactivate cruise control.
Helping to smooth out the power delivery and engine braking is the latest Allison 1000 six-speed automatic transmission. Allison has gone through the box and wrung out every last bit of mechanical efficiency, all while beefing it up to handle the extra torque of the upgraded diesel motor. The transmission controller, meanwhile, has been reprogrammed to work with the exhaust brake to keep braking as smooth and controlled as possible.
Other features include a class-leading 250 lb-ft of torque available to the PTO, a Tow/Haul mode for better control and transmission safety, a cab warm-up feature that can increase the load on the engine on cold mornings to get the heater warmed up faster and manual shifting control. Those sticking with gasoline will get an upgraded 6L90 six-speed automatic transmission, an upgrade from the 6L80 found on current models.
The end result, which can be combined with an upgraded transfer case on 4WD models, is a beefy diesel drivetrain that can handle a claimed class-leading maximum tow rating of 20,000 lbs for fifth-wheels and 16,000 lbs for a ball hitch, along with a claimed class-leading payload capacity of 6,335 lbs. In other words, more than enough to blow the Ram HD and the Ford F-Series Super Duty out of the water (though specs on the 2011 Super Duty haven't been announced yet). Not enough? Gross Vehicle Weight Rating increases to 13,000 lbs while Front Axle Weight Rating jumps to 6,000 lbs.
Making all that pulling power possible are 11 all-new frames to underpin the 11 cab and box configurations. Fully-boxed all the way around, Chevy says the new frames are five times stiffer on their own while the hydroformed front sections are 125% stiffer. Chevy even did haulers and outfitters a favor and added access holes in the frame for a gooseneck trailer hitch.
Below the new frames is a completely redesigned front suspension that's been strengthened to allow any 4WD model to be fitted with a snow plow. Chevy says the new design is smoother riding and more easily adaptable to handle specific workloads than the competition. Backing it up is a new asymmetrical leaf-spring rear suspension with wider leafs, resulting in a higher payload capacity and less axle-hop. New shocks and hydraulic body mounts smooth everything out.
Though Chevy boasts that its new exhaust brake system made it possible for an engineer to tow a trailer over the Rockies with minimal use of the brake pedal, the company went ahead and upped the brakes as well. Now there are 14-in. rotors standard on all four corners to match the truck's increased weight and tow ratings and the steering has also been enhanced.
While the 2011 Chevrolet Silverado Heavy Duty may not offer the stark visual upgrade that our Truck of the Year, the Ram HD, does, it more than makes up for it in substance. With its big new diesel and chunky frames, the Silverado HD has stolen the big truck spotlight for now, but there's a new Super Duty lurking on the horizon that could give the Chevy a run for its money. Stay tuned, the truck wars are getting interesting.