1972 Gmc 1500 Custom 4-wheel-drive Pick-up Factory Tachometer A/c Dual Exhaust on 2040-cars

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GM files for Z71 Trail Boss trademark

Try as they might to keep their plans a secret, automakers have their hands tipped through a variety of methods – be they through loose lips, spy shots or patent and trademark applications. That's how we know, in this instance, that General Motors is working on (or at least considering) an off-road machine wearing the name Z71 Trail Boss – the name which our compatriots at AutoGuide.com tell us that GM has registered for use on light-duty trucks. Now if that alphanumeric designator sounds familiar, it should. GM has long used it to designate the off-road packages on many of its body-on-frame trucks from Chevy and GMC. These days you can order a Z71 package on the Chevy Colorado, Silverado, Tahoe and Suburban and on the GMC Canyon, Sierra and Yukon. The package typically includes components like a beefed-up suspension bits, high-capacity air cleaner and underbody protection plates. The Trail Boss designator would seem to suggest something further reaching than a suspension package, though. Just what it would entail we don't know; minds immediately start running toward Chevy or GMC going after the Ford F-150 Raptor, but we'll likely be looking at something closer to the Trailhawk packages Jeep offers on the likes of the Renegade and Cherokee. Featured Gallery 2015 Chevrolet Tahoe Z71 View 16 Photos News Source: AutoGuide.comImage Credit: Chevrolet Chevrolet GM GMC Truck SUV Off-Road Vehicles patent trademark

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.

2022 GMC Sierra spotted with minimal camouflage

By all accounts, GM's current full-size truck twins, the Chevrolet Silverado and GMC Sierra, are good trucks that are in many ways competitive with the sales-leading Ford F-150 and a fresh Ram 1500 that's regularly nipping at the Bowtied truck's tailgate. Considering the cashflow generated by the segment, though, it's no surprise to see a refreshed version of the GMC Sierra testing with some light camouflage hiding some of the upgraded bits and pieces. We'll get to what we can see in just a moment, but first we'll point out what we can't see in these spy shots. What the GM pair really needs is a competitive interior. The current Silverado and Sierra are bridled by dashboards, door panels and instrument clusters that simply aren't good enough when compared to their Ram and Ford competitors. We've spoken with a few designers from GM, and they are well aware of the criticisms that have been levied at their full-size truck duo, so we'd be shocked if there wasn't a heavily revised interior lurking for the trucks' next refresh. Hopefully a future set of spy photos will give us a better look at what's inside, because from this far-away, through-the-windshield look doesn't give us much information. Will the Sierra share an interior with the redesigned Yukon? We'll just have to wait and see, but suffice it to say that any improvement will be welcome. Moving to the exterior, we can clearly see that the blocky, angular look of the current Sierra will continue through this refresh. A tiny look through the heavy tarp covering the truck's face reveals a black plastic mesh grille, but we're sure there's plenty of chrome hiding under there, too. We're left to wonder if that opening allows for a camera or radar to peek through, but rumors suggest GM's well-regarded Super Cruise could be on the menu within the next few years. We have no idea what's under this test truck's hood, but we wouldn't imagine there will be much change to the current truck's solid list of powertrain options. Here's hoping the 3.0-liter Duramax inline-six diesel engine gets the cooling it needs to raise its tow rating to match its class-leading efficiency, because it's arguably otherwise the best light-duty diesel offering in America. We know the automaker is working on electric powertrains, too, but we expect to see those debut first in the Hummer-branded truck that will be sold in GMC dealerships.