09 Gmc Sierra 3500hd Sle 6.6 Duramax 6spd Allison 4x4 Flat-bed New-tires 1own Tx 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.

GM mulling off-road variants of fullsize SUVs

According to General Motors, owners "just love off-roading with [its fullsize body-on-frame sport utility vehicles]," namely the 2015 Chevrolet Tahoe and Suburban and GMC Yukon. If that's the case, it's a bit odd that sales of the previous generation of these models with the Z71 off-road package didn't sell particularly well.
Perhaps, considering this disconnect between owner's thoughts and desires with actual sales, it's not surprising that General Motors is reportedly "considering" an off-road specific model. That means the package would include styling changes and badges along with suspension modifications and larger wheels with appropriately sized fender flares.
There's no indication if the off-road model would be called Z71 or when it may potentially go on sale, assuming it ever goes on sale at all.

2015 Chevy Tahoe, Suburban and GMC Yukon unveiled

General Motors has today unveiled its new family of fullsize SUVs, including the 2015 Chevy Tahoe, its longer Suburban sibling, and their GMC Yukon, Yukon XL and Yukon Denali cousins. More efficient powertrains, improved aerodynamics, increased connectivity and better overall refinement are what Chevy and GMC say will separate their new SUVs from the current generation.
Sporting a tried-and-true body-on-frame architecture, these full-size SUVs feature platforms that are stronger and offer a wider rear track for "a more planted stance," according to Chevy and GMC. Mounted at the front of each SUV is an EcoTec3 powertrain, which consists of a standard 355-horsepower, 5.3-liter V8 (or a 420-hp, 6.2-liter V8 for the GMC Yukon Denali alone) with direct injection, cylinder deactivation and continuously variable valve timing, that's paired with a Hydra-Matic 6L80 six-speed automatic transmission. The setup is said to be more efficient than before, though official EPA fuel economies for each vehicle are not yet available. To help the powertrain achieve the best possible fuel economy in these 5,000+ pound SUVs, the new styling was developed with aerodynamics in mind. For the same reason, electric power steering also makes its debut in the Tahoe/Suburban/Yukon family.
The front fascias of the Chevy Suburban/Tahoe and GMC Yukon are distinct, but from the base of the A-pillars back, they share most of the same styling cues. This now includes inlaid doors that tuck into the door sills, instead of over them, which improves aerodynamics and fuel economy, and lessens interior noise. The hoods and liftgate panels now are made of aluminum in an effort to reduce vehicle weight. Chevy and GMC also tout that the Tahoe/Suburban and Yukon don't share a single piece of sheetmetal or lighting element with the brands' full-size pick-up trucks.