2015 Gmc Sierra 2500hd Denali - Testdrivenow review by auto critic steve hammes

When choosing the right heavy duty truck for you a lot of the decision making centers around the engine and not so much the type of nuanced leather appointed front seats it may have, but those features now come into play in the new 2015 GMC Sierra Denali HD.GMC’s ¾- and 1-ton heavy duty trucks were last redesigned for the 2011 model year at which point a luxuriously trimmed Denali model debuted, offering a more premium tool in this workhorse segment. And now, major updates greet the 2015 models with all-new exterior styling featuring better aerodynamics and improved cooling, a modernized interior carried forward from the Sierra 1500, and a host of smart features to make towing easier on the truck as well as the driver.Sierra HD models are offered in regular cab, the new double cab and crew cab styles, in either 2 or 4-wheel drive, matched with either a 6’6” or 8’ box and the 3500 grade can be ordered as a dually. But this top-of-the-line 2500 Denali model comes exclusively in the incredibly spacious Crew Cab configuration with the standard-sized box.Owners can keep the standard gasoline fed 6.0-liter V8 or upgrade to this 6.6-liter Duramax diesel at a significant cost of $8,588. It comes bundled with an Allison 6-speed automatic transmission, a less aggressive rear axle ratio and an engine block heater. Known for their bullet-proof reliability, better mileage and turbo induced prodigious levels of torque, diesel engines and their associated clatter are like a badge of honor in this segment. But a reality check shows that it’s the gas engine that provides greater maximum payload capacity and equal trailer towing in addition to providing similar mileage – I averaged around 14mpg for the week.At the hitch, this rig can tow 13,000 pounds and you can fill-up the bed with over 2,500 pounds of payload and with a 36 gallon fuel tank it’s possible to drive over 600 miles between fill-ups.The diesel flaunts its trailering advantage when using a fifth-wheel by permitting up to 17,100 pounds. New for 2015 is a system that integrates cruise control, auto grade braking and an exhaust brake for ultimate driver confidence while towing. And though it’s not geared to be a street truck, I’d sure like to feel more energy from this big engine even if it is lugging around over 3 ½ tons.The most surprising thing about this truck is how sluggish it feels. I know; it’s a big, heavy duty machine. But 765 pound feet of torque has never felt so lifeless. The first inch of travel pedal produces negligible momentum. And from a company that used to produce the smoothest riding trucks in the biz this one still feels and sounds very trucky.And that’s why the Denali badge seems a bit bastardized here. Yes, there’s an exclusive 8” touch screen with IntelliLink, a Bose audio system, heated and cooled leather seats, a heated steering wheel and a power sliding rear window but the entire package seems a bit half-hearted. And while the Sierra HD is certainly very quiet inside and full of useful features – including the optional Driver Alert Package with the vibrating Safety Seat – there’s a quality level concerning fit and finish that seems less than Denali-approved. I’d also expect to see features like smart key access and push button start, power folding outside mirrorss, better ventilation for rear seat passengers, and more cleverness in the bed. But as long as Denali models account for more than 1/3 of all HD Crew Cab sales, it’ll be here to stay.Pricing for this Denali starts at $54,835 and totals $64,575 as tested with 20” wheels, a sunroof and dual alternators to keep all the goodies running.