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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 recalls select Tahoes, Yukons, Escalades for rear driveshaft issue

GM is recalling a number of its full-size SUVs due to an issue with the rear driveshaft assembly that could ultimately result in driveshaft failure. The actual number of total vehicles involved in the recall is small at just 1,789, but it’s spread out across the entire 2021 model year full-size GM vehicle lineup. That means a small number of every model is being recalled, including the Chevrolet Tahoe, Suburban, GMC Yukon, Yukon XL and the Cadillac Escalade and Escalade ESV. GM traced the issue back to certain driveshaft assemblies with ball bearings that were not properly heat treated. If theyÂ’re not properly heat treated, GM says that the balls may deform over time, causing noise and vibration. Continue to drive in this condition, and GM says the affected joint in the driveshaft assembly could seize, causing loss of drive power. However, the problem wonÂ’t present itself all at once, as GM says there will be a gradual increase of noises and vibrations before total failure. For those few owners with affected vehicles, GM says that it will replace the left and right rear driveshaft assemblies with properly-built units. Per usual with recalls, this will be done at your local dealership at no cost to the owner. If you have one of the recalled SUVs, expect to be notified mid-March. Related video:

GM's 2014 Trucks Receive Five-Star Crash Rating

This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings. The highly-anticipated 2014 Chevrolet Silverado 1500 and GMC Sierra 1500 received Overall Vehicle Scores of five stars from the National Highway Traffic Safety Administration's New Car Assessment Program, the highest possible safety rating. They are the first pickup trucks to receive a five-star rating since more rigorous safety standards were implemented in 2011, according to Autoblog. General Motors said in a written release that new technologies, ultra-high-strength steels and six standard airbags helped the automaker improve the truck's performance in crashes. Related Gallery Ford, Chrysler Offer Power With Smaller Engines In New Trucks GM GMC Safety