2007 Corvette 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.

Consumer Reports criticizes small turbo engines for misleading performance, fuel economy claims [w/video]

Consumer Reports has taken aim at at small-displacement, forced-induction engines, saying the powerplants don't manage to deliver on automaker fuel economy claims. Manufacturers have long held that smaller, turbocharged engines pack all power of their larger displacement cousins with significantly better fuel economy, but the research organization says that despite scoring high EPA economy numbers, the engines are no better than conventional drivetrains in both categories. Jake Fisher, director of automotive testing for Consumer Reports, says the forced induction options "are often slower and less fuel efficient than larger four and six-cylinder engines."
Specifically, CR calls out the new Ford Fusion equipped with the automaker's Ecoboost 1.6-liter four-cylinder engine. The institute's researchers found the engine, which is a $795 option over the base 2.5-liter four-cylinder, fails to match competitors in acceleration and served up 25 miles per gallon in testing, putting the sedan dead last among other midsize options.
The Chevrolet Cruze, Hyundai Sonata Turbo and Ford Escape 2.0T all got dinged for the same troubles, though Consumer Reports has found the turbo 2.0-liter four-cylinder in the BMW 328i does deliver on its promises. You can check out the full press release below. You can also read the full study on the Consumer Reports site, or scroll down for a short video recap.

1983 Motorweek showdown pits Porsche 928S vs. Chevy Camaro Z28

Last month, Motor Trend threw the Camaro Z/28 and Porsche 911 GT3 into the bear pit and let them fight it out. Way back in 1983, MotorWeek had the same idea, comparing the Camaro Z/28 to the Porsche 928S. At the time, the Camaro was America's best selling sports coupe, the 928S was Porsche's top-of-the-line model that also had the highest top speed of any car sold here. And the price differential was even more stark then: $13,600 for the Camaro, $45,000 for the Porsche. That put the Z/28's cast-iron, 5.0-liter V8 with 190 horsepower and 240 pound-feet of torque against the all-aluminum 4.7-liter V8 with 234 hp and 263 lb-ft in the 928S. Even with that and the Camaro being 14 inches longer than the Porsche, the American was a surprising 40 pounds lighter than the German. The show took them to Summit Point Raceway in West Virginia to see how close a relative performance bargain could hang with a the German GT. Both had five-speed manual transmissions, but the high-speed corners and tight sections of Summit Point would test other handling variables, including the "bone-rattling" Camaro's solid rear axle and disc and drum brake setup vis-a-vis the four-wheel disc brakes and independent suspension on the "firm-but-smooth" Porsche. Paradoxically, the larger disparity 22 years ago resulted in a closer result. Check out the video to see how the Summit was won. News Source: MotorWeek via YouTube Chevrolet Porsche Coupe Luxury Performance Classics Videos chevy camaro z28 porsche 928 retro review