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2015 Sierra All Terrain HD looks ready to hit heavy-duty trails

GMC is getting its heavy-duty trucks ready for the mud this summer with its All Terrain package for the Sierra 2500HD and 3500HD. Meant to blend style, tech and ruggedness, the pack includes a lot of extra chrome outside and an off-road package underneath.
The 2015 Sierra All Terrain HD trucks naturally come standard with four-wheel drive with an electronically controlled transfer case to handle things in the dirt. The Z71 off-road package is also standard, which includes Rancho twin-tube shocks, hill descent control and a skid plate. To add some style when off the beaten path, the pack includes chrome trim on the mirror caps, lower bumper and grille surround, plus LEDs around the headlights and 18-inch wheels (20-inchers are optional on the 2500HD). The 3500HD also gets chrome, adjustable outside camper mirrors. The interior receives a technology upgrade thanks to the standard rearview camera and IntelliLink infotainment that can act as a Wi-Fi hotspot through OnStar 4G LTE, read text messages and includes Siri Eyes Free for iPhone users.
The All Terrain package goes on sale on both trucks this summer and is offered on either the SLE or SLT trim levels in double cab and crew cab models. The standard engine is the 6.0-liter V8 with 360 horsepower and 380 pound-feet of torque, but the Duramax 6.6-liter, diesel V8 with 397 hp and 765 lb-ft is also available. The gas engine is mated to a Hydra-matic six-speed automatic, and the diesel uses an Allison six-speed automatic. Scroll down to read the full announcement about these heavy-duty off-roaders.

GM exploring ways to raise half-ton Duramax diesel tow rating

Lots of truck owners cheered when GM announced fuel economy numbers for the 2020 Chevrolet Silverado with the 3.0-liter Duramax diesel inline-six. Even after Ram let loose its EPA mileage ratings for the 2020 Ram 1500 EcoDiesel, the Chevy oil-burner still took the trophy. The victory was years in the making, GM engineers spending an entire four-year development cycle refining the LM2 Duramax to increase mileage. The tradeoff, as well all know by now, is towing; the Duramax in half-ton duty pulls a maximum 9,300 pounds in the Silverado. Rivals across town can do more, the Ford F-150 PowerStroke rated at 11,500, the Ram 1500 EcoDiesel game to pull 12,560. GM engineer John Barta told Muscle Cars & Trucks that more hauling chops could be on the way, explaining, "We’re actually looking at upgrading some of the materials around (the engine bay) to see if we can maybe raise our tow rating." Engine bay materials are at issue due to thermal complexities underhood. John Barta, GM's assistant chief engineer of diesel engine controls, said the Duramax's inline-six configuration allowed engineers to get emissions hardware like the combined selective catalytic reduction, diesel oxidation catalysts, and diesel particulate filter unit closer to the engine, where it heats up quicker, getting emissions down quicker. But that filter puts another heat source in those confines, enforcing a cap on the tow rating to keep the engine and other systems from overheating. "If you look under the hood," he said, "youÂ’ll see a significant amount of silver ‘moon tapeÂ’ around to make sure things arenÂ’t getting overheatedÂ… if we were to go up in higher towing, which we can, we start impacting the possibility of deteriorating some of the components.” There isn't much space for more grille, so swapping for a better grade of "moon tape" or a different kind of material could reduce engine bay heat, extracting a higher tow rating in the process.  It's important to note a point Barta's been making for months about the Duramax figures, though. "Even though itÂ’s nice to brag about big numbers, in reality, light duty customers are not towing that large with their trucks," and, "We do know that (95 percent) of our light duty customers donÂ’t tow over 9,000 pounds." On our First Drive of the 2020 Silverado diesel we called out the tow rating, but emphasized that the Chevy and GMC have more important challenges to overcome.

Least reliable cars and trucks of 2022

Related: Most reliable cars and trucks of 2022   Every year, Consumer Reports ranks new cars based on their predicted reliability. We often see Toyota, Lexus, and a few other automakers near the top. But on the other side of the coin, the list of least reliable vehicles sometimes contains surprises.   The organization surveys its members to determine the vehicles that exhibited the most problems over the prior year. Owners are asked about creaks and rattles, the durability of parts and trim, and mechanical issues. Consumer Reports assigns a weight to each problem and then uses them to create a score, with 100 being the best. Some familiar names appear on the list of least reliable vehicles (in order with the lowest predicted reliability score at the top), but there are a few eyebrow-raising models, followed by CR's score: Ford F-150 Hybrid: 4 Hyundai Kona Electric: 5 Lincoln Aviator: 8 Nissan Sentra: 9 Ford Explorer: 16 Chevrolet Bolt: 17 Chevrolet Silverado 1500/GMC Sierra 1500: 19 Jeep Gladiator: 21 Mercedes-Benz GLE: 23 Jeep Wrangler: 24 Consumer Reports noted that sedans are the most reliable vehicle category and found that trucks are far lower on the list. That said, the survey showed that trucks from American brands tended to have better reliability scores, so it’s surprising to see GMÂ’s big two and the Ford F-150 on the list. Part of their problematic ownership experience could be due to the fact that all three trucks have received recent updates, and the Ford was completely redesigned for 2022. New tech, fresh drivetrain components, and other improvements can upset the balance of reliability and make newer models look less dependable than their older counterparts. Related video: Green Chevrolet Ford GMC Hyundai Jeep Lincoln Mercedes-Benz Nissan Car Buying Truck Crossover Hatchback SUV Electric Hybrid Sedan Consumer Reports reliability