1997 Gmc Yukon Sle Sport Utility 4-door 5.7liter, 4wd, Low Miles, Tow, Roof Rack on 2040-cars

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Chevy's 6.6-liter Duramax is pretty much all new

To say there's a heated battle in heavy-duty pickups is an understatement, with Chevrolet, Ford, and Ram constantly trading blows of increased torque, horsepower, and towing capacity. The latest salvo is the revised, more powerful turbo diesel 6.6-liter Duramax V8 in the 2017 Chevy Silverado. It has 910 pound-feet of torque, an increase of 145, putting it nearly level with the Ford Super Duty. Here's a closer look at where those gains come from. How exactly did Chevrolet add all that torque plus 48 horsepower? The automaker essentially took a fine-tooth comb to the entire engine. Chevy says it changed 90 percent of the V8, and the cumulative effect of those small changes adds up to big increases. As you might guess, the turbocharger is updated. The larger unit features electric actuation of the variable nozzle turbine (VNT), and what Chevy calls a double axle cartridge mechanism that separates the VNT moving parts from the housing. That helps with heat performance as well, with a claim that the exhaust side of the turbo can run continuously up to 1,436 degrees Fahrenheit. Helping that cause are six exhaust gaskets made of Inconel - an nickel alloy that contains chromium and iron – and upgraded stainless steel for the exhaust manifold. Despite having the same cast iron cylinder block, albeit with some minor enhancements, the engine has new cylinder heads, pistons, piston pins, connecting rods, and crankshaft, which have all been upgraded to handle 20 percent higher cylinder pressures. Alongside the increase in pressure, Chevrolet also increased the cylinder head's structure with a honeycomb design. The pattern features high-strength aluminum with dual layer water jackets that not only improve strength, but also optimize water flow for better cooling. For 2017, the cylinder head also benefits from integrated plenum that aids the engine in getting more air under heavy loads. The cylinder head isn't the only component to get a minor update, as the pistons have a larger diameter pin for improved oil flow. The same detailed improvements has been bestowed to the humble connecting rods (second in our hearts only to the inanimate carbon rod). The new design has the bolts oriented roughly 45-degrees to the rod instead of parallel. The angle split design, as it's called allows for easier passage through the cylinder.

2018 GMC Sierra 2500HD All Mountain concept: Nothing stops it in its tracks

Winter may not be the best time for sports cars, but snow and ice can still provide a ton of fun in the right vehicle. The Porsche Macan GTS I had back in January was a riot in the snow, and it was wearing nothing more than a good set of winter tires. What you really need to conquer the frozen north is tracks. These replace wheels with the same sort of equipment that helps tanks and snowmobiles roll over damn near everything in their paths. That's what makes the 2018 GMC Sierra 2500HD All Mountain concept so awesome. That and the 910 pound-feet of torque from the 6.6-liter Duramax turbo diesel V8. The All Mountain concept is set to debut this week in Veil, Colorado, home to ski slopes, log cabins and nearly year-round snow pack. The truck is based off a standard GMC Sierra 2500HD. The turbo-diesel V8 makes 445 horsepower in addition to the mountain of torque. Power is sent to all four corners through an Allison 1000 six-speed automatic. The new treads come courtesy of Mattracks. The 150 Series tracks aren't cheap — well into five figures with installation — but they give you a nice 16-inch surface at each corner. Other changes and add-ons include graphics on the bodywork, a RIGID E-Series 30-inch light bar, LEDs on the wheel well and underbody, Thule snowboard racks, a roll-up tonneau cover and a new speaker system from Kicker. The truck will stay on display in Veil all winter, though a similar concept will be making its way to various auto shows, starting with Los Angeles next week. Related Video: This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings. Featured Gallery GMC Sierra All Mountain Concept: LA 2017 View 9 Photos Related Gallery 2018 GMC Sierra 2500HD All Mountain concept View 10 Photos News Source: GMCImage Credit: Live photos copyright 2017 Drew Phillips / Autoblog.com GMC Truck Off-Road Vehicles

GM planning to put its fullsize pickups on a big diet, too

General Motors is just coming off a complete redesign of the Chevrolet Silverado and GMC Sierra for 2014, but in the US fullsize truck market, there is no rest for the weary. According to Reuters, plans are already unfurling for both trucks to drop pounds from their curb weight over the next few years, but this will unlikely be able to keep pace with the 700-pound diet targeted for the next-generation Ford F-150, a truck expected to debut late next year.
The biggest weight reduction for these trucks might not be available until the next full redesign, which will likely happen around 2019, but the article says that smaller updates could shave pounds in the meantime. Two examples given include an "aluminum-intensive" version of the Silverado that could shed 250 pounds and debut around the same time as the lighter-weight, aluminum-bodied 2015 Ford, and there is also talk of reducing weight for driveline components such as axles and driveshafts. These changes are all part of an attempt to meet strict new fuel economy standards coming in 2017, targets which will get even tougher in 2025.