1998 Gmc Jimmy Sle Sport Utility 4-door 4.3l on 2040-cars

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2015 GMC Yukon and Yukon XL hit the floor at LA

The middle child of General Motors' trio of truck-based SUVs, the GMC Yukon and long-wheelbase Yukon XL, received their auto show debut at today's 2013 Los Angeles Auto Show. Showing off a bigger, bolder look, particularly on its Denali trim, the Yukon sports prominent chrome grille instantly identifies GMC's new top-end SUV.
The Yukon is will come to market with a pair of engines. The base 5.3-liter V8 pumps out 355 horsepower and 383 pound-feet of torque, while the higher-end models benefit from the same direct-injected, 6.2-liter V8 as the Escalade. That engine makes 420 horsepower and 450 pound-feet of torque, with fuel economy seeing a likely boost thanks to an active fuel management system. Like the Tahoe, Suburban and Escalade, the Yukon takes advantage of a six-speed, column-mounted automatic transmission.
The cabin has seen significant upgrades in terms of materials and technology, with an eight-inch touchscreen display and IntelliLink standard in both Yukon and Yukon Denali. Fold-flat second and third-row seats come standard, while a power option is available, as well. Other techy features include active noise cancellation and standard Bose stereos.

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 GMC Sierra Regular Cab revealed

Despite initially launching in just the Crew Cab configuration, the lineup of 2014 GMC Sierra and 2014 Chevrolet Silverado trucks will eventually grow to include three cab sizes and three bed lengths. Oddly enough, our first look at the Regular Cab bodystyle has arrived in a General Motors press release discussing the aerodynamics of the new truck, with an image showing a Sierra Regular Cab testing in the wind tunnel. GMC's website says that Regular Cab and Double Cab models will be available by summer.
While it really didn't take too much imagination to figure out what the two-door version would look like, this Regular Cab Z71 looks pretty sharp with its standard-length (6.5-feet) bed - a longer bed will also be offered. In regards to the aero tuning of the 2014 Sierra, these images show just how far GM has gone in maximizing the truck's fuel efficiency and reducing its noise, vibration and harshness (NVH) levels. Interestingly, the press release shows visual evidence that keeping the tailgate up is best for aero - there's always been some Mythbusters-level contention about such things -but GM also says that adding tonneau covers (preferably soft) and running boards can also help improve the overall aerodynamics. Scroll down for all of this aero info in the official press release.