1969 Chevrolet Camaro 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.

2016 Chevrolet Colorado Diesel First Drive [w/video]

The first thing you notice inside the diesel Chevy Colorado is that it's quiet. Almost too quiet. A lot has been done to quell noise and vibration with this new powertrain, and it shows – or rather, doesn't. There's some characteristic diesel clatter at idle, but even then it's distant and practically disappears as you start moving down the road. At full throttle, when the engine is at its noisiest, the sound isn't particularly diesel-like, just a pleasant intake breath. The accompanying smoothness is almost eerie. When we ask where all the noise went, Chevy's engineers, marketing guys, and PR reps all explain that this refinement is what Americans want. We're still not sure. This is a truck, after all, and the diesel pickup customer is different from the guy buying a diesel Cruze for his highway commute. Chevy contends that they're also not the same as the buyer of a Silverado HD. Although this 2.8-liter Duramax four-cylinder has been in service elsewhere around the globe, its first US application is in the Colorado and its GMC Canyon twin. The engine puts out 181 horsepower and 369 pound-feet of torque, and it does so unobtrusively as a result of a lot of modifications for our market. To keep normal diesel sensations out of the cabin, the intake and oil pan both get acoustic treatments. A new, thicker material is used for firewall sound deadening. Redesigned balance shafts have tighter tolerances to increase smoothness. The diesel powertrain is smoother than the Colorado's gasoline V6. One of the more interesting and certainly unexpected vibration-reduction changes is a special torque converter from German supplier LuK equipped with a centrifugal pendulum absorber. This pendulum spreads from the center of the torque converter as engine speed increases and is tuned to absorb the four-cylinder's second-order vibrations, not just those in a narrow frequency band. It does an admirable job, especially considering the engine's biggish, 0.7-liter cylinders, which lead to bigger vibrations. The result is a powertrain that's smoother than GM's (not particularly smooth) corporate V6, which is available in the standard Colorado. It's quieter than a Cruze diesel and even out-softens some gas direct-injection engines on the market. Paradoxically, it may be the most refined of all of the Colorados. No vibration comes through the steering wheel, pedals, floorboards, or even the rearview mirror. But you can tell it's a diesel when you hit the throttle.

2015 Chevrolet Corvette Z06 Beauty Roll

For those of you paying attention, we've really ramped up the old Autoblog video game these days. Our new series Car Club USA joins Translogic and The List, and there are more Daily Drivers and Short Cuts than ever. But sometimes, all you care about is the car. The Autoblog Beauty-Roll video series has one goal: bring you glossy video of cars, and nothing but. We're collecting moving pictures of all the cars we test, inside and out. Each episode comes with a hit of engine sound – start-up and with a few revs – to round out the package. Set your resolution to max, kick it into full-screen, turn up the sound, and enjoy today's subject, the 2015 Chevrolet Corvette Z06. Oh, and if you'd like more Beauty-Roll, click here to see the back catalog.