1989 Gmc S-15 Special 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.

GMC could have used Jeep's prized grille design on its born-again Hummer

General Motors confirmed it's bringing the Hummer nameplate back on an electric, GMC-badged pickup by publishing a dark photo of its front end. The battery-powered drivetrain under the sheetmetal represents a tectonic shift, but we noticed another flagrant break with tradition: it wears six slot-like inserts instead of seven like on every previous Hummer and countless Jeeps. Adding an extra slot wouldn't have landed GMC in hot water. The seven-slot grille has historically been associated with Jeep, and the company proved it's willing to go to significant lengths to ensure another automaker — especially one it perceives as a rival — doesn't use it. Parent company Fiat-Chrysler Automobiles (FCA) bitterly sued Mahindra over the Roxor's design, including its five-slot grille, and won in 2019, forcing the Indian firm to unveil a redesigned side-by-side for the 2020 model year. And yet, stylists would have very likely been able to get away with it on the Hummer. While General Motors owns Hummer, the brand traces its ancestry to 1970, when American Motors Corporation (AMC) purchased Jeep from Kaiser and changed the name of its General Products Division to AM General Corp. The division manufactured the rear-wheel drive, CJ-based DJ for the United States Postal Service and began developing the Humvee in 1979. Jeep and AM General went their separate ways when Renault began investing in AMC. Foreign companies weren't allowed to own defense contractors, and AMC had more to gain by gradually selling out to Renault than by keeping AM General, so it divested the division to LTV Corporation in 1983. Humvee production started shortly after, but no one protested its seven-slot grille because there was no risk of it stealing sales from a comparable Jeep model. It was manufactured exclusively for the U.S. Army, and civilian sales weren't planned. H2SUV View 4 Photos The original civilian Hummer released in 1992 must have raised more than a few eyebrows but, here again, it didn't directly compete with one of Jeep's off-roaders, so no one complained. It was huge, correspondingly expensive, and its portal axles made the YJ-generation Wrangler wet its pants. It's the H2 concept (pictured above) unveiled at the 2000 Detroit Auto Show that set off alarm bells in Auburn Hills. DaimlerChrysler's lawyers counted the slots in the chrome-plated insert that dominated its front end and shuddered when they reached seven.

2018 GMC Acadia with 'Christmas Aero' modification gets in the wind tunnel

Tis the season of "Big" - big cheer, big parties, big bowls of eggnog, big decorations, and when it comes to your family hauler, big drag. Festive drivers who festoon their crossovers, minivans, and SUVs with wreaths, Rudolph noses, fuzzy antlers, and rooftop Christmas trees undo the years of work that car engineers devote to fractional gains in fuel economy. To put numbers to such fuel-guzzling madness, GMC started with a 2018 Acadia, optioned it with the Xmas Aero Package - both Standard and Plus versions - put it in Lockheed-Martin's wind tunnel. The resulting dip in fuel economy results probably won't surprise anyone who's used a roof rack - or, for that matter, their car's air conditioning. However, it might surprise you to find out which seemingly substantial decoration had no effect, and which seemingly innocuous decoration was about twice as bad as running the A/C on its Mr. Freeze setting. Check out the brief video above for the results. And consider placement of that bow carefully.