2011 Chevrolet Tahoe 4wd Lt-edition (z71 Off Road Package) 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.

Next-gen GMC Sierra spied with diesel power

The next generation of GM trucks is arriving soon, and we're expecting a huge leap forward over the current lineup. The Chevy Silverado and the GMC SIerra sell extremely well, but haven't done much to move the segment forward in a long time. The Ford F-150 has an all-aluminum body and turbocharged V6 power. The Ram 1500 gained a diesel and coil spring suspension. These spy shots show that diesel may be in the cards for GM. Some quick shots and copious use of flash show what is most likely a tank for diesel exhaust fluid and a diesel particulate filter, both necessary equipment for any modern diesel. It's unclear what form factor that engine will come in, though GM has a number of engines to choose from, including the 2.8-liter inline four that's found in the Colorado and Canyon, though that may be a little light duty for the Silverado and Sierra. Other rumors surrounding the trucks suggest a move to an aluminum cab while retaining a steel bed. That seems like a reasonable move for GM, even if the company was attempting to shame Ford for its move to aluminum a few years ago. Look for more news as early as the Detroit Auto Show in January. Related Video: Featured Gallery 2019 GMC Sierra spy shots View 21 Photos Image Credit: Spied Bilde Spy Photos Chevrolet GMC Truck

GM recalls Cadillac ATS and Chevy Impala for separate issues

The National Highway Traffic Safety Administration added two recalls from General Motors in the government organization's daily update of safety campaigns. Both were for failing to meet Federal Motor Vehicle Safety Standards but for completely separate reasons. The larger recall covers 58,698 units of the 2013-2015 Cadillac ATS, but it doesn't really carry huge safety concerns. In vehicles produced between April 25, 2012, and February 9, 2015, the controls for the tilt and slide of the moonroof are not recessed enough, as required by federal law. According to NHTSA, it's possible that someone could inadvertently activate the auto-close for the roof panel, which the agency claims increases "the risk of personal injury." Dealers will install a new trim plate that will add the necessary clearance. The other campaign covers 1,177 examples of the 2014 Chevrolet Impala from between November 15, 2012, and May 27, 2014. However, this is actually a repeat of a previous recall on the Chevy and the Cadillac XTS from 2014. The affected Impalas here "were remedied incorrectly" under the earlier campaign, according to NHTSA. On these sedans, it's possible the electronic parking brake might not fully disengage and still remain in some contact with the rotor, which is in violation of federal rules. The fault can cause excessive heat from the brakes that could potentially lead to a fire, according to NHTSA. To fix the problem, dealers will reprogram the electronic parking brake control module. Show full PR text RECALL Subject : Inadvertent Press of Roof Panel Switch/FMVSS 118 Report Receipt Date: FEB 24, 2015 NHTSA Campaign Number: 15V106000 Component(s): VISIBILITY Potential Number of Units Affected: 58,698 All Products Associated with this Recall Vehicle Make Model Model Year(s) CADILLAC ATS 2013-2015 Details Manufacturer: General Motors LLC SUMMARY: General Motors LLC (GM) is recalling certain model year 2013-2015 Cadillac ATS vehicles manufactured April 25, 2012, to February 9, 2015. In the affected vehicles, the power-operated roof panels auto-close when the non-recessed "Slide" or "Tilt" switches are pressed. As such, these vehicles fail to comply with the requirements of the Federal Motor Vehicle Safety Standards (FMVSS) No.