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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 readying aluminum-body fullsize pickups

Ford's extensive use of aluminum in its 2015 F-150 is a big deal. A really big deal. Big enough, in fact, that General Motors is reportedly changing its fullsize pickup strategy. According to The Wall Street Journal, The General has locked in partnerships with Alcoa Inc. and Novelis Inc. - companies that will supply aluminum for the next-generation Chevrolet Silverado and GMC Sierra trucks.
"Ford's introduction of the 2015 F-150 pickup truck was a game changer, and it's the first, not the last, conversion of this type," Novelis spokesperson Charles Belbin told the Journal. The switch to aluminum has allowed Ford to shave roughly 700 pounds off its fullsize truck's curb weight. And while official mileage ratings have not been announced, the weight loss should go a long way for improving efficiency, especially when combined other efficiency-minded improvements including better aerodynamics and new, turbocharged V6 engines.
Of course, aluminum-bodied cars are nothing new. But extensive use of aluminum in a major, best-selling product like the Ford F-150 is expected to kick off widespread use of this weight-saving material as availability rises and cost decreases. The WSJ reports that GM had originally explored the idea of moving to aluminum pickups back in 2008, but abandoned the idea due to cost concerns amid economic woes.

2017 GMC Acadia, tech and design, Indycar Boston | Autoblog Podcast #476

Episode #476 of the Autoblog Podcast is here. This week, Dan Roth, and guest George Kennedy talk about the 2017 GMC Acadia, this year's New England Motor Press/MIT Technology conference on the intersection of technology and design, and the failure of the efforts to bring an Indycar race to Boston. It all starts with the Autoblog Garage - check it out! Check out the rundown with times for topics, and thanks for listening! Autoblog Podcast #476 Topics 2017 GMC Acadia Tech intersecting Design Grand Prix of Boston In The Autoblog Garage 2017 GMC Acadia 2016 Toyota Highlander Hybrid 2016 BMW 750i 2016 Honda Civic Coupe Touring Hosts: Dan Roth Guests: George Kennedy Rundown Intro & Garage - 00:00 GMC Acadia - 1:00 Tech/Design - 34:13 Indycar Boston - 46:52 Total Duration: 54:22 Get The Podcast iTunes – Subscribe to the Autoblog Podcast in iTunes RSS – Add the Autoblog Podcast feed to your RSS aggregator MP3 – Download the MP3 directly Feedback Email – Podcast at Autoblog dot com Review the show in iTunes