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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.

Question of the Day: Worst year of the Malaise Era?

The Malaise Era for cars in the United States spanned the 1973 through 1983 model years, and featured such abominations as a Corvette with just 205 horsepower (from the optional engine!) and MGBs with suspensions jacked way up to meet new headlight-height requirements. There were many low points throughout this gloomy period, of course. The horrifyingly low power and fuel-economy numbers for big V8s during the middle years of the Malaise Era make a strong case for 1974 or 1975— the years of Nixon's resignation and the Fall of Saigon, respectively— as the most Malaisey years. But then the GM-pummeling debacles of the Chevy Citation and Cadillac Cimarron could make an early-1980s year the low point. 1979, the year of the ignominious Chrysler bailout? You choose! Related Video:

'84 MotorWeek Cherokee, Bronco and Blazer comparison indulges your SUV nostalgia

These days, truck-based, full-frame SUVs are somewhat of a rarity on the auto landscape due to the rapid rise in popularity of easier-driving, car-based crossovers. Although, without the gradually building popularity of these chunky, high-riding vehicles decades ago, it's unlikely that America's roads would be filled with so many CUVs today. In its latest dig into the archives, MotorWeek has found a 1984 comparison test of a trio of these early Sport Utility Wagons, as long-time host John Davis called them, that helped get acceptance of this segment going. This is a red, white and blue test of the SUVs from American automakers at the time and pits the Chevrolet Blazer, Ford Bronco and Jeep Cherokee (specifically in Wagoneer guise) against each other. Driving manners and interior usability are considered in the evaluation, but Motorweek actually takes these vehicles off road, too. Among the bigger revelations is the improvement in on-road ability in the past 30 years. While specific 0-60 times aren't given, all three models take around 10 seconds just to get to around 50 miles per hour in the 500-feet on-ramp acceleration test. Check out this clip to see just how far this segment has progressed in the past three decades or just get a blast of nostalgia from these now vintage models. News Source: MotorWeek via YouTube Chevrolet Ford Jeep SUV Off-Road Vehicles Classics Videos Ford Bronco chevy blazer