2003 Gmc Yukon Xl 2500 Slt Sport Utility 4-door 6.0l on 2040-cars

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Canada opens probe into 250,000 GM pickups, SUVs over brake performance

Transport Canada, the auto safety regulator, has opened a probe into braking issues in nearly 250,000 General Motors full-size pickups and SUVs after U.S. officials launched a similar probe last year, the agency said on its website. The U.S. National Highway Traffic Safety Administration (NHTSA) in November into 2.73 million U.S. 2014-2016 model year SUVs and pickups after receiving 487 reports of hard brake pedal effort accompanied by extended stopping distance that were attributed to deterioration of the engine-driven brake assist vacuum pump. Transport Canada's probe covers 249,700 2015 through 2017 model year vehicles including the Cadillac Escalade, Chevrolet Suburban, Chevrolet Tahoe and GMC Yukon as well as 2014-2017 Chevrolet Silverado LD and GMC Sierra LD vehicles. The U.S. agency said it had reports of nine incidents of vehicles incurring damage as a result of colliding with another vehicle or fixed object at low speeds and reports of two injuries. NHTSA said if the pump fails to operate, the amount of brake power assist can be significantly reduced, extending vehicle stopping distance. The NHTSA sent GM an information request in a Feb. 7 letter. A GM spokesman said he had no update on the investigation. Reporting by David Shepardson; editing by Jonathan Oatis

IIHS gives good ratings to 4 of 8 midsize pickups in crash test

Versions of the Toyota Tacoma, Chevrolet Colorado and GMC Canyon Crew Cab earned top ratings in a new crash test of midsize pickup trucks from the Insurance Institute for Highway Safety, while two versions of the Nissan Frontier earned marginal ratings. But the organization gave poor marks to all eight pickups tested for their dim headlights. Overall, four of the eight pickups evaluated earned good ratings for protecting occupants in all five crash test categories — the Tacoma double cab along with crew cab versions of the Colorado, Canyon and Tacoma. But the poor headlights and lack of an automatic emergency braking system blocked any of the pickups from qualifying for the IIHS's Top Safety Pick awards. The study looked at two pickup body styles using 2017 models: crew cabs, which have four full doors and two full rows of seating, and extended cabs, which have two full front doors, two smaller rear doors and compact second-row seats. It subjected each to five tests, and it evaluated the performance of front crash prevention systems and headlights. The Toyota Tacoma crew cab was the only pickup in that class that earned a good rating for structure in the small overlap test, which replicates what happens when a vehicle clips a tree, pole or another vehicle that has crossed the center line. The model's Access Cab extended-cab version was rated similarly, though its structure was rated acceptable. "This group of small pickups performed better in the small overlap front test than many of their larger pickup cousins," says David Zuby, the Institute's executive vice president and chief research officer. "The exception was the Nissan Frontier, which hasn't had a structural redesign since the 2005 model year." The extended-cab versions of the Chevy Colorado and GMC Canyon earned acceptable ratings, while both the Nissan Frontier king-cab and crew-cab models were rated marginal. Toyota says its 2018 Tacoma will feature upgraded headlights and a standard autobraking system that can detect pedestrians. "Headlights are basic but vital safety equipment. Drivers shouldn't have to give up the ability to see the road at night when they choose a small pickup," Zuby said. Related Video: Auto News Chevrolet GMC Nissan Toyota Safety Truck Videos gmc canyon nissan frontier chevrolet colorado

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.