2004 Gmc Sierra 3500 Base Standard Cab Pickup 2-door 6.6l on 2040-cars

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2024 GMC Sierra HD AT4X and Extreme AEV muscle their way into the lineup

The new AT4X variant of GMC's 2024 Sierra HD pickup series officially joins the stable this week, giving pickup truck box-checkers yet another off-road trim to chase. Well, two trims, technically, as GMC took the opportunity to announce that the AT4X will also be offered with an upfit package from American Expedition Vehicles, appropriately named the Extreme AEV Edition that takes its cues from the same package offered on the Sierra 1500 AT4X. And with its introduction, the 2024 GMC Sierra HD lineup is now complete.  GMC's Sierra AT4X models mirror the ZR2 packages offered on the updated Chevrolet Silverado. If you paid any attention at all to the Silverado HD ZR2's introduction earlier this month, you'll be familiar with the formula. Key upgrades include a 1.5-inch factory lift, standard electronic locking rear differential, Multimatic DSSV shocks and 35-inch Goodyear Territory all-terrain tires. It also gets beefier skid plates —  both the steel protecting the transfer case and the aluminum piece up front. With the updated 6.6-liter Duramax diesel, GMC says it'll tow up to 18,500 pounds.  "GMCÂ’s AT4X trim, which will be available across the entire GMC truck lineup, offers customers more premium and capable choices when it comes to ‘do-it-allÂ’ capabilities," said GMC VP Duncan Aldred. "Each model delivers unique strengths, with the all-new Sierra HD AT4X taking it to the max, enabling you to go virtually anywhere, with the towing power to bring your recreational toys, gear or camper along for the journey." And by "do it all," he means all the luxury stuff too, judging by the Obsidian Rush interior, which GMC says includes massaging leather front seats and real ash wood trim. The better from which to feel the shove of the AT4's two available 6.6-liter engines, one a gasoline-burner rated at 401 horsepower and 464 pound-feet of torque, the other a Duramax turbodiesel making 470 horsepower and 975 pound-feet of torque. You'll need the latter if you want to hit GMC's advertised towing capacity.  And don't forget the Extreme AEV Edition, which will surely come with a Denali-rivaling (and still TBA) price tag. The stamped steel bumpers stand out right away, as do the integrated front recovery points and winch mount. The package also adds more skid plates protecting the steering gear and transfer case. Its 18-inch "Salta" wheels are also unique.  GMC says it will be cranking out 2024 Sierra HD AT4Xs and Extreme AEV Editions by the third quarter.

'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).

2018 GMC Sierra Denali can help you tow without breaking a sweat

Towing a trailer once meant that only those who possessed certain knowledge would be able to go fishing, tow a race car or pull a camper safely. For me, it took four long years of practice working a job behind the wheel of a jacked-up Ford F-250, hauling tons upon tons of mowing equipment for my local parks department, to become proficient. Just how far things have come since then became evident after a recent trip to Utah with GMC, in which we used the half-ton Sierra Denali to tow a set of Polaris side-by-sides through the state. Modern safety technology and a suite of electronic aids make towing simple enough that anyone with a driver's license and something to haul can do it. This revelation came behind the leather-wrapped and heated steering wheel of GMC's outgoing 2018 Sierra Denali. Sitting in the plush, heated and cooled captain's chair, I could barely feel the 6,000 pounds I was towing behind me. Even GMC's smallest full-size truck engine, a 5.3-liter V8 generating 355 horsepower and 383 lb-ft of torque, felt like overkill for what used to amount to a heavy load. With Utah's pristine landscape, the plush confines of the cabin and the uneventful nature of modern towing, mile after mile just streamed by at highway speeds without incident (or excitement). When we finally reached our destination a few hours later, one of GMC's representatives who had chosen to sit in the rear of the cab asked me what I thought about the drive. I pondered for a few minutes and answered with this: "Modern pickup trucks have removed nearly every skill-based variable once associated with towing. I could drive this truck and trailer confidently with just one finger." Consider the near overabundance of towing-assistance systems in the GMC Sierra Denali that I piloted through Utah. Let's start with the most basic of towing skills — something that's now been relegated to the annals of history: reversing a pickup to meet the trailer's hitch. Once upon a time, this required knowing a truck's dimensions and understanding proximity, as well as having a keen eye, a steady foot for both the gas and the brake and the patience to get it right. Now, though, pickups such as the Sierra Denali offer customers a trailer reverse camera system that helps the driver align truck to hitch with pinpoint accuracy.