2008 Chevrolet Colorado Ls Extended Cab Pickup 4-door 3.7l 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 Design shows what could have been and what might be

We periodically like to check in with GM Design's Instagram account to see what they're cooking up. Even better is when we catch a glimpse of an alternate history of what legendary designers from The General's past were thinking, though those ideas may not have made it into production. This week, for example, the account posted some illustrations from George Camp, whose career at GM spanned nearly four decades, from 1963 to 2001. One of the renderings is of what appears to be a 1971-72 Pontiac GTO Judge, but with two headlights instead of the production unit's quad beams. The rear departs from the canonical version most dramatically, with a massive integrated wing. Other bits that didn't make the production cut include large side vents, a gill-like side marker and rectangular intakes below the headlights that wouldn't be out of place on a modern design today. Amazingly, from what we can make out of the date, it appears that the drawing was done sometime in 1965, which makes it quite prescient.           View this post on Instagram                       A post shared by GM Design (@generalmotorsdesign) There's also a very aerodynamic interpretation of a Corvette ZR-1. To our eyes it splits the difference between the 1986 Corvette Indy concept and a fourth-generation F-body Pontiac Firebird, so perhaps parts of Camp's work on this sketch did make it into physical form. There's also a radical sports car concept from May 1970 that resembles the Mazda RX-500 concept from the same year, a Syd Mead-looking Cadillac coupe, and an Oldsmobile with a cool take on the company's trademark waterfall grille and elements of the Colonnade Cutlass at the rear. Other recent posts include a FJ Cruiser-like off-road EV, a sleek coupe with the Chevy corporate grille, and a rendering of a Silverado-esque pickup that looks far better than the current production version.           View this post on Instagram                       A post shared by GM Design (@generalmotorsdesign) It's pretty easy to lose hours in the account, but it's always fascinating to see GM's visions of what could have been and what might be. Related Video:

General Motors Recalls Nearly 780,000 Cars To Fix Deadly Problem

General Motors is recalling nearly 780,000 compact cars in North America because the engines can shut down unexpectedly and cause crashes. The company says six people have been killed in crashes related to the problem. The recall affects Chevrolet Cobalts and Pontiac G5s from the 2005 through 2007 model years. U.S. safety regulators say the weight of the key ring and rough roads can move the ignition switch out of the run position, cutting the engine and electricity. If that happens, air bags may not work. GM says there have been 22 crashes from the problem. All happened at high speeds. Dealers will replace the ignition switch for free. GM says owners should remove nonessential items from key rings until the problem is fixed. Related Gallery Chevy Impala Earns Highest Accolades From Consumer Reports Recalls Chevrolet GM Pontiac Cobalt