2014 Gmc Sierra 1500 Slt on 2040-cars

Auto blog

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.

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.

GM recalling 54k Cadillac SRX, HD pickup models

There are more recalls to report General Motors, but these latest actions pertain to newer examples of the Cadillac SRX, Chevrolet Silverado HD and GMC Sierra HD. With so much scrutiny on the company's recall strategy, GM is under increasing pressure to call in defective models more quickly, and it appears to be doing so here.
Here in the US, the automaker is recalling 50,571 Cadillac SRX crossovers from the 2013 model year fitted with the 3.6-liter V6 because the transmission control module programming can cause a three- or four-second lag in acceleration at low speeds. The explanation filed with the National Highway Traffic Safety Administration states, "if the following sequence occurs within two seconds: during an upshift from first to second gear (8-10 mph), the driver then brakes the vehicle to less than 5 mph, and then accelerates again," the delay can occur. According to Automotive News, the recall effects 56,400 vehicles worldwide, and the company is not aware of any crashes caused by the problem. The fix consists of a transmission control module (TCM) reflash.
In a separate recall, GM is repairing 51 Chevrolet Silverado HD and GMC Sierra HD pickups from the 2015 model year in the US. In vehicles with diesel engines and dual fuel tanks, the nuts that connect the fuel pipe to each side of the transfer pump between the tanks may be improperly torqued, which could cause a fuel leak. Obviously, this could be a fire hazard. The remedy is simply tightening the hardware. According to GM spokesperson Alan Adler, there have been no fires actually caused by the potential leak. "Only 21 of the trucks are in customer possession and they can be fixed anytime because there are no parts involved. The others are being fixed at dealerships," Adler said in an email to Autoblog.