2004 Gmc Yukon Denali 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.

Chevy Silverado, GMC Sierra 4.3-liter EcoTec3 V6 nets 18 mpg city, 24 highway

There is no doubting that fuel economy has become an important factor in the highly competitive fullsize truck market, with the Ford F-150 EcoBoost V6 and Pentastar V6-powered Ram 1500 setting quite a precedent in recent years. Now it's General Motors' turn. The General has just announced that the new base V6 used in the 2014 Chevrolet Silverado and GMC Sierra 1500 models will return an EPA-estimated 18 mpg city and 24 mpg highway in two-wheel drive trim, regardless of cab configuration.
While these figures don't go so far as to earn GM any "best-in-class" fuel economy claims (thanks to the 25-mpg Ram 1500 HFE), this new 4.3L EcoTec3 V6 does edge the F-150 and Toyota Tundra while boasting best-in-class numbers for torque, payload and towing capacity among six-cylinder rivals. This all-new engine produces 285 horsepower and 305 pound-feet of torque, and it gives the 2014 Silverado and Sierra the highest towing rating among standard V6 models with a 7,200-pound towing capacity - besting the Ram by 700 pounds, the base F-150 by 1,100 pounds and coming within 200 pounds of the V8-powered Nissan Titan. Scroll down for the official press releases from Chevrolet and GMC.

GM recalling 316k vehicles due to headlamp faults

General Motors has announced a recall covering 316,357 vehicles globally, due to the possibility of sporadic or permanent failure of the low-beam headlamps. 273,182 of these vehicles are in the United States, while the remaining affected units are in Canada, Mexico, and elsewhere. This recall includes the 2006-09 Buick LaCrosse (pictured above), 2006-07 Chevy TrailBlazer and TrailBlazer EXT, 2006-07 GMC Envoy and 2006 GMC Envoy XL, 2006-07 Buick Rainier, 2006-08 Saab 9-7X, and 2006-08 Isuzu Ascender. In an email sent to Autoblog, General Motors explains that if the headlamp driver modules are not functioning correctly, "the low-beam headlamps and daytime running lamps could intermittently or permanently fail to illuminate." GM states that this problem does not affect things like high-beams, turn signals, marker lamps, or foglamps. As of this writing, GM states it "has not been able to confirm whether the HDMs in these vehicles caused any vehicle accidents." The National Highway Traffic Safety Administration has been notified, but the recall has not yet posted to the government agency's website. Scroll down to read the full details in GM's email. General Motors is recalling 273,182 Buick LaCrosse sedans and Chevrolet, GMC, Buick, Saab and Isuzu midsize SUVs in the U.S. for possible intermittent or permanent loss of low beam headlamps. Affected models are: 2006-2009 Buick LaCrosse sedans; 2006-2007 Chevrolet TrailBlazer and 2006 TrailBlazer EXT; 2006-2007 GMC Envoy and 2006 Envoy XL; 2006-2007 Buick Rainier; 2006-2008 Saab 9-7X and 2006-2008 Isuzu Ascender midsize SUVs. If the headlamp driver modules is not operating correctly, the low-beam headlamps and daytime running lamps could intermittently or permanently fail to illuminate. This condition does not affect the high-beam headlamps, marker lamps, turn signals, or fog lamps. GM has not been able to confirm whether the HDMs in these vehicles caused any vehicle accidents. The total population, including the U.S., Canada, Mexico and exports from North America is 316,357. The NHTSA was sent the Part 573 information for this recall on November 25. It has not yet posted to the NHTSA website. Featured Gallery 2008 Buick LaCrosse CXS News Source: General Motors Recalls Buick Chevrolet GM GMC Isuzu Saab SUV Sedan chevy trailblazer buick rainier isuzu ascender