1999 Chevrolet Tahoe Lt Sport Utility 4-door 5.7l 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.

2014 Chevrolet Silverado and GMC Sierra debut all-new designs, three new engines

General Motors has finally dropped the curtain on the 2014 Chevrolet Silverado and 2014 GMC Sierra. Both trucks have undergone substantial revisions with updated versions of the company's 4.3-liter V6, 5.3-liter V8 and 6.2-liter V8 engines. In a shot across the bows of both Ford and Chrysler, GM says it won't use a V6 engine adapted from passenger car applications. Instead, it developed the 4.3-liter engine based on its proven truck-duty architecture.
All three mills will boast direct injection fuel systems as well as a new cylinder head design. Combined with a revised piston, the new engines feature a smaller combustion chamber with a compression ratio of 11:1 or higher depending on the application. Cylinder deactivation and continuously variable valve timing are all part of the recipe, and each engine is paired with a six-speed automatic transmission with auto grade breaking. So far, no fuel economy or horsepower figures have been released, though GM says the new engines will best their predecessors in both areas.
Outside, the trucks feature a number of enhancements to reduce drag and wind noise, and GM claims both the Silverado and Sierra will offer buyers some of the quietest cabins in the class. Extended cab models now feature front-hinged rear doors to allow easier access to the back passenger area, and Crew Cab buyers can now select between a five-foot, eight-inch bed or a six-foot, six-inch bed. Buyers with a mind toward going off road will also rejoice in the return of the Z71 package, complete with Rancho shocks, front tow hooks and additional under-body protection.

Chevy Volt sales drop in June, Nissan Leaf inches upwards

Different month, same story. That's the gist of the monthly US sales numbers from the Chevy Volt and the Nissan Leaf. These were the first two mass-market plug-in vehicles to go on sale in the US and we've been comparing their sales numbers for what seems like ages now. So far, the 2014 tale of the tape shows the all-electric once again trumping the plug-in hybrid. The last time the Volt outsold the Leaf was in October 2013. Chevrolet sold 1,777 Volts in June. That was good enough to be the Volt's best sales month of the year, but it's down 34 percent from the 2,698 units sold in June 2013. In fact, it's on par with the 1,760 Volts sold in June 2012. Given the steady sales, General Motors might need to push up the release of the next-gen Volt to gin up excitement, especially if it also offers some of the things that current Volt drivers say they want improved: more range, a lower price and a fifth seat. GM also said it sold 85 Spark EVs in June, an increase of 215 percent over June 2013 Nissan sold 2,347 Leafs last month. The good news continues for Nissan, which says it sold 2,347 Leafs last month. That's an increase of 5.5 percent over 2013 numbers and makes 2014 the best June ever for Leaf sales. Let's credit Texas. Toby Perry, Nissan's director of EV sales and marketing, said in a statement that, "Since the Texas state incentive went into effect in May, we've seen a big jump in Leaf sales in the Austin, Dallas and Houston markets. Our dealers are telling us that they saw more traffic in their stores, and they had their best Leaf sales performance in the last weekend in June." Even with that increase, Atlanta remains the top Leaf market. Nissan has sold 12,736 Leafs in the US so far this year; Chevy 8,615 Volts. Our detailed monthly sales write-up of green cars in the US, including plug-in vehicles, hybrids and diesel cars, is coming soon. For now, we invite you to discuss these numbers in the Comments. Related Gallery 2013 Nissan Leaf View 55 Photos News Source: GM, Nissan Green Chevrolet Nissan Electric Hybrid PHEV ev sales