2005 Gmc Sierra Z71 Crew Cab 4x4 on 2040-cars

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Next-gen GM SUVs caught wearing new boxy bodies [w/video]

We recently drove the brand-new 2014 Chevrolet Silverado and found it to be vastly improved compared to the outgoing model. And now that The General's pickup trucks have been squared away, it's time to focus our attention onto their passenger-friendly companions, the Chevrolet Tahoe and GMC Yukon (above).
Our spy photographers have passed along a huge smattering of photos (and a video), showing the new SUVs out testing. Both the short- and long-wheelbase models were spied, and while the overall shape of the vehicles hasn't changed all that much, we expect the updates to be substantial. In addition to new powertrain options, like GM's new small-block V8, we expect the interiors of both SUVs to get massive makeovers, providing better materials throughout their cabins and quieter, more refined environments. We even hear that some trick new suspension developments may be in store for upper-end models.
Visually, these spy shots allow us to see a couple of new details on the SUVs' front and rear fascias, including LED running lamps on the Yukon and some interesting LED taillamp treatments. Of course, the obvious third party missing from this set of photos is the Cadillac Escalade, but as we reported earlier, GM is working to further differentiate the 'Slade from the rest of the fullsize SUV lineup, and is working to make the new model "much less ostentatious."

'Killing a Duramax' Gale Banks YouTube series methodically tunes a diesel to death

Learning or perfecting a skill by watching YouTube videos is known as attending YouTube University. GM Authority picked up on one of the video site's more fascinating courses, hosted by Gale Banks; in a fair world, he should be referred to as Professor Banks when it comes to diesel engines and truck tuning. A few months after GM introduced the updated L5P 6.6-liter Duramax diesel V8 in the 2020 Chevrolet Silverado HD and GMC Sierra HD that ships with 454 horsepower and 910 pound-feet of torque, Banks decided he wanted to methodically tune the engine to death. The purpose of the resulting series, called "Killing a Duramax," is to push more power out of the engine in order to discover which parts break and when — or, as Banks puts it, force-feed the Duramax "until the crank hits the street and the heads hit the hood." With that knowledge, Banks can figure out all the weak points on his way to building what he calls a "Superturbo," that being a supercharged, twin-turbo race engine with more than 1,000 hp. What makes the series fascinating is Banks' knowledge, paired with the company's comprehensive iDash engine monitoring system that keeps tabs on a glut of parameters every step of the way. So for instance, you get Banks explaining the differences between inches of mercury and barometric pressure, how those are different from the water content of the air measured in grains, then showing those readouts on the iDash, then explaining in detail how they affect the air density in the Duramax system. The stock Borg-Warner variable turbo gets a lot of airtime — Banks accuses it of being "out to lunch" because he feels it's the weakest link on the engine. That turns into a turbo teardown and a deep explanation of performance pitfalls, such as when air pressure on the turbine begins to diverge from the boost pressure coming from the compressor. Banks says he can keep close tabs on where power's coming from, because the iDash monitors the horsepower contribution provided by the ambient air, the turbo, and the intercooler separately. The major changes so far are a stouter Precision 7675 turbo and TurboSmart wastegate (episode 5), a twin intake (episode 6), a custom liquid-cooled intercooler from a marine engine, a new GM oil cooler and synthetic oil (episode 10), and new injectors (episode 11).

2022 GMC Sierra AT4X First Drive Review | Luxury off-roader

BORREGO SPRINGS, Calif. – What does the 2022 GMC Sierra AT4X have in common with the Aston Martin Vulcan, Mercedes-AMG GT, Camaro ZL1 and Ford GT? The answer: Multimatic DSSV spool-valve dampers. These dampers – or shock absorbers as theyÂ’re also called – are a lot like the adaptive dampers found in many sport and luxury vehicles. In a general sense, they allow drivers to select how soft or firm a ride they want, but the Multimatic dampers are quicker to respond and have additional benefits related to off-roading.  Off-roading is the main reason this new AT4X model has been added to the Sierra lineup this year, along with its elevated levels of luxury. ItÂ’s a big step up from the existing less-capable AT4 trim, which misses out on the DSSV dampers, electronically locking front and rear differentials, and 32-inch Goodyear Wrangler DuraTrac Mud-Terrain tires. The timing of this debut coincides with a significant overhaul for the entire 2022 Sierra lineup, including revised styling, a more muscular 2.7-liter turbo-four engine, and most notably, an interior overhaul that replaces this generationÂ’s dull and outdated dashboard with a fresh, modern and more competitive interpretation bolstered by a large 13.4-inch touchscreen powered by the Android Automotive OS. Upping the luxury further is a new, fully-loaded Denali Ultimate trim that includes the Super Cruise automated driving system, though our time in the revised 2022 Sierra was almost entirely in the AT4X. In addition to the off-road equipment and interior improvements listed above, the Sierra AT4X features the 420-horsepower 6.2-liter V8 as standard equipment, improved underbody skid plates, and a new Terrain drive mode. But thatÂ’s not all, because the AT4X is also differentiated by the X-less AT4 with a cabin thatÂ’s almost as extravagant as that luxurious Denali model, minus the availability of Super Cruise. Ventilated seats with massage functions, premium leather upholstery, wood trim and Bose audio are all standard. Altogether, this big truck could be the perfect way to get to your next glamping adventure. We had the opportunity to check out the AT4XÂ’s capabilities within the Anza-Borrego Desert State Park, a few hours east of San Diego. There, we encountered long stretches of dried riverbeds, narrow chokepoints as well as steep climbs and descents. After dropping pressures in the Goodyear mud-terrain tires to a flaccid 15 psi, we skimmed through the silted riverbeds with ease.