2012 Gmc Denali Crew Cab 4x4 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 can't keep up with most popular pickup orders

With the market for pickup trucks at its best since before the recession, General Motors can't afford any hiccups with the launch of its new 2014 Chevrolet Silverado and GMC Sierra twins, but it sounds like the popularity of V8-powered trucks is causing some supply-chain issues. Bloomberg reports that GM is experiencing a shortage of 5.3-liter V8 engines because an unnamed parts supplier has been unable to keep up with demand. This is leading GM to restrict the number of V8 Silverado and Sierra trucks that Chevrolet and GMC dealers are allowed to order.
Although it's unclear how long it will take to resolve the parts shortage, GM doesn't have much time to sort it out, as a new Ford F-150 looms on the horizon. At launch, GM's fullsize trucks were offered only with a base 4.3-liter V6 and the 5.3-liter V8, but a burlier 6.2-liter V8 will be available soon. Interestingly, at least at the moment, GM truck buyers don't seem as willing to downsize to V6 power as buyers of the F-150, which gets some 42-percent of its sales from trucks equipped with its EcoBoost V6 engine (not including the normally aspirated base V6).
Working out the kinks in the Silverado and Sierra's supply chain couldn't be more important to the health of the company. Full-size pickups are a huge profit driver - in 2012, the trucks were said to make up about two-third of GM's total profits.

GM issues stop-delivery for 2015 Chevrolet Colorado and GMC Canyon

General Motors is issuing a stop-delivery order for its latest midsize pickups, the 2015 Chevrolet Colorado and GMC Canyon, because the driver's side airbag might not be wired correctly. The total number of vehicles affected is still being determined.
According to the statement from GM, the problem, "affects the vehicles' two-stage airbag system by reversing the deployment sequence and disrupting the deployment timing of the driver airbag stages." That means in an accident the bag may not work correctly.
Most of the affected trucks are still on the assembly line, in transit or unsold at dealers, says GM. Until a way to repair the problem is found, customer deliveries are stopped. However, "a small number" of them are in the possession of buyers. GM is contacting these people by phone and by FedEx letter to have the vehicles returned to dealers. In the meantime, they'll be given a loaner to drive.