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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 recalling nearly 4,000 vehicles over airbag concerns

Four different General Motors vehicles from the 2012 model year are being recalled over a potential airbag issue. The driver's side airbag shorting bar in the 2012 Buick Verano and 2012 Chevrolet Camaro, Cruze and Sonic might make contact with the airbag terminals, even during a crash. If so, the airbag won't deploy when it should, possibly increasing injury to the driver.
The recall is expected to begin on February 13 for the 3,896 units that might be affected. GM will notify owners who can then take their vehicles to dealers to have the airbag coil replaced. A bulletin from the National Highway Traffic Safety Administration below has more info.

GM investing $167m in Spring Hill for new midsize vehicles

General Motors has announced a large investment in its Spring Hill, Tennessee facility. The former home of Saturn production will be getting a $167 million addition to a previously announced $183 million, to cover a pair of new midsize vehicles. The investment is expected to create 1,800 jobs at the factory.
That $350 million is being divvied up for a pair of programs at Spring Hill. The first will take the bulk of the money ($223 million) and create 1,000 of the 1,800 jobs, while the other will take the remaining $127 million and generate the leftover 800 positions. But GM says the investment will cover "midsize vehicle programs." So what could they be?
The leading candidate in our minds is a new crossover for Buick, called the Anthem, that will slot between the Encore and Enclave, but will be slightly smaller than the Equinox and Terrain. As we've explained, the new model will likely be the first product to sport GM's new D2UX platform, which will eventually replace both the Delta and Theta platforms. Spring Hill is already building the Equinox, so there could be some credence to this theory.